Patent Publication Number: US-2023153342-A1

Title: Clustering and dynamic re-clustering of similar textual documents

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. Non-Provisional Pat. Application No. 16/434,888, entitled “CLUSTERING AND DYNAMIC RE-CLUSTERING OF SIMILAR TEXTUAL DOCUMENTS,” filed Jun. 7, 2019, which claims priority to and the benefit of U.S. Provisional Application No. 62/843,007, entitled “CLUSTERING AND DYNAMIC RE-CLUSTERING OF SIMILAR TEXTUAL DOCUMENTS,” filed May 3, 2019, each of which are hereby incorporated by reference in their entirety for all purposes. 
    
    
     BACKGROUND 
     It is beneficial in a variety of applications to cluster samples of text into groups that are similar. This can be done in order to facilitate textual searching by identifying inter-related groups of text samples within a corpus of text samples. Such grouping can facilitate text search or other text-related processing by limiting the search to text samples within a cluster of related text samples (e.g., a cluster of text samples that are similar to a query text string), avoiding the time and computational cost of searching through the text records that are not within the cluster of related text samples. Additionally, identifying such clusters within the textual portions of records that include non-textual information (e.g., that include geographical information, time stamps, weather-related information, information related to the performance or operation of a technological system) may facilitate operations based on the non-textual information. 
     SUMMARY 
     Natural language processing or other methods can be used to generate clusters of text samples and to identify, for individual text samples, one or more clusters to which the individual text sample should be assigned. This can be done based on a determined similarity between the text samples and/or between a text sample and the text samples in a cluster. This clustering can be done in order to facilitate searching within the text samples (e.g., by limiting the sample-level searching to text samples within an identified cluster relevant to a search query), to facilitate modeling of a managed network whose operations are related to the text samples, to identify and/or automatically implement a course of action that has been effective when implemented in response to other text samples assigned to a cluster, to allow all of the incident reports associated with text samples in a particular cluster to be resolved or to be otherwise manipulated as a group, or to provide some other benefit. 
     In one possible example, a query can include a sample of text describing a problem that a user is experiencing. A machine learning (ML) model or some other algorithm could then be applied to assign the query to a cluster of other textual records (e.g., other queries, incident reports that include queries and/or resolutions thereof, knowledgebase articles) that are similar to the query. Information related to the selected cluster could then be provided to a user and/or to a technician. Such information could include knowledgebase articles, resolved similar incident reports, or some other information that could provide a solution and/or answer to the query. Additionally or alternatively, similar queries or other information in the selected cluster could be provided in order to facilitate determination of a solution and/or answer to the query. This clustering may improve the quality of results provided to the user and/or reduce the amount of time spent by the user before determining and implementing a solution to the problem represented by the query. 
     However, implementing such clustering can be computationally expensive, requiring extensive processor cycles, memory, or other resources to generate an ML clustering model based on a training corpus of textual records. Accordingly, ML models may be re-generated, based on updated training sets of textual records, according to a regular schedule. Users may manually specify clusters that have value and the specified clusters can be retained through re-generation of the ML model in order to retain the benefits of the specified clusters. For example, an identified cluster could correspond to an ongoing event and/or to a class of incidents that the user is likely to continue to experience. Retaining a specified cluster can include defining one of the clusters in the re-generated ML model based on the specified cluster. For example, a cluster in the re-generated ML model could be defined based on the identity of training textual samples belonging to the specified cluster, based on a centroid or other information defining the specified cluster, or based on some other characteristic of the specified cluster. Additionally or alternatively, retaining a specified cluster can include using information about the specified cluster as a seed in the re-generation of the ML model. 
     Between scheduled re-generations of the ML model, additional textual records (e.g., newly-generated incident reports) can be accumulated. These additional records may belong to additional clusters that are not reflected in the ML model, and so may be incorrectly assigned to clusters of the ML model and/or assigned to a set of residual textual records. To avoid the computational cost of completely re-generating the ML model to include the additional textual records, the ML model may be updated via an iterative update algorithm to take into account the information represented by the additional textual records. 
     This can include attempting to form additional clusters of textual records from within a set of residual textual records. When a new textual record is received, it can be compared to the existing clusters. If the new textual record does not fit any of the existing clusters (e.g., by being less similar to each of the clusters than a specified threshold similarity), the new textual records could be assigned to a set of residual textual records. Accordingly, the set of residual textual records comes to include textual records that were determined, by the ML model, not to belong to any of the clusters defined by the ML model. If one or more additional clusters are identified within the residuals, the ML model can be updated to include the additional clusters. In addition, any textual records, from within the set of residual textual records, that correspond to the identified additional clusters can be re-assigned from the set of residuals to the additional clusters. 
     In some examples, user(s) may manually specify, a prioiri, conditions under which cluster formation should happen. Such manually-specified conditions may be specified according to a geographical location, a tag or other metadata, the identity of an individual associated with the textual record (e.g., a user who generated an incident report that forms a part of the textual record), or according to some other consideration. Further clusters may then be identified within the user-specified conditions. This manual pre-clustering can provide a variety of benefits. For example, the clustering algorithm may perform more efficiently by operating on fewer textual records. These methods can also provide benefits by aligning the identified clusters with an organization’s considerations such that the generated clusters are aligned with those considerations. Additionally, the clusters generated within a user-specified condition may be improved due to the pre-partitioning made possible by the user-specified conditions. 
     Transmitting a representation of one or more textual records in a corpus of textual records can include transmitting a variety of different information. In some examples, transmitting a representation of a textual record includes transmitting an identification number (e.g., a global unique identifier (GUID)), time and date stamp, a location within a database, or some other identifying information that can enable an end-user instance to identify the represented textual record in a database or to otherwise access the represented textual record. Additionally or alternatively, transmitting a representation of a textual record can include transmitting a copy of the textual record itself or a portion thereof. For example, transmitting a representation of a textual record can include transmitting a copy of a ‘problem resolution’ field of an incident report. 
     Transmitting a representation of one or more textual records in a corpus of textual records can include transmitting a representation of one or more clusters of the textual records. This can include transmitting an identification number (e.g., a GUID), a location within a database, or some other identifying information that can enable the end-user instance to identify the represented cluster of textual records. Additionally or alternatively, a representation of the contents of the cluster of textual records could be transmitted. This could include transmitting identification information for the textual records within the cluster (e.g., GUIDs, locations within a database), all or part of the contents of the textual records within the cluster (e.g., text from ‘problem resolution’ fields of incident reports within the cluster), the contents of one or more representative textual records associated with the cluster (e.g., a knowledgebase article associated with the cluster, a ‘problem resolution’ field or other contents of an incident report that is near a centroid of the cluster), or some other content associated with the cluster. 
     Note that the methods described herein to determine similarity between textual records, and to perform clustering based on such determined similarities, can be applied to other types of records. For example, records including both textual aspects (e.g., text fields of an incident report that describe a problem, a solution to the problem, or some other information) and non-textual aspects (e.g., dates, geographical locations, enumerated categories, an identifier related to a user or technician, or some other non-textual information of an incident report) could be clustered by an ML model based on both the textual and non-textual information. Indeed, the methods described herein could be applied to determine numerical similarities and/or to perform clustering based on such determined numerical similarities for completely non-textual records (e.g., combined genotype/phenotype information for individuals receiving a treatment, historical usage statistics for users of a media or network service, etc.). 
     Accordingly, a first example embodiment may involve a computer-implemented method that includes: (i) receiving, by a prediction computational instance and from an end-user computational instance, a first textual record, wherein the end-user computational instance is dedicated to a managed network, and wherein the prediction computational instance and the end-user computational instance are both disposed within a remote network management platform; (ii) determining, by an ML clustering model of the prediction computational instance that represents a set of clusters of textual records, that the first textual record corresponds to a particular cluster in the set of clusters of textual records; (iii) transmitting, by the prediction computational instance and to the end-user computational instance, a representation of the particular cluster, (iv) receiving, by the prediction computational instance and from the end-user computational instance, a second textual record; (v) determining, by the ML clustering model, that the second textual record does not correspond to any cluster of textual records of the set of clusters of textual records; (vi) responsive to determining that the second textual record does not correspond to any cluster of textual records of the set of clusters of textual records, adding, by the prediction computational instance, the second textual record to a stored set of residual textual records; (vii) identifying, by the prediction computational instance, an additional cluster of textual records based on the stored set of residual textual records; and (viii) transmitting, by the prediction computational instance and to the end-user computational instance, a representation of the additional cluster of textual records. 
     In a second example embodiment, a computer-implemented method includes: (i) receiving a first plurality of textual records; (ii) determining, based on the plurality of textual records, a first ML clustering model that represents a first set of clusters of textual records, wherein each cluster of the first ML clustering model corresponds to a respective set of textual records within the first plurality of textual records; (iii) receiving additional textual records; (iv) using the additional textual records to update the first ML clustering model via an iterative update process; (v) receiving an indication of a preferred cluster of the first set of clusters of textual records represented by the first ML clustering model; (vi) determining that a model refresh criterion is satisfied; and (vii) responsive to determining that the model refresh criterion is satisfied, determining, based on the additional textual records, a second ML clustering model that represents a second set of clusters of textual records, wherein each cluster of the second ML clustering model corresponds to a respective set of textual records within the additional textual records, and wherein a first cluster within the second set of clusters of textual records of the second ML clustering model is determined based on the preferred cluster. 
     In a third example embodiment, a computer-implemented method includes: (i) obtaining a plurality of textual records divided into clusters and a residual set of the textual records, wherein an ML clustering model divided the plurality of textual records based on a similarity metric; (ii) receiving, from a client device, a particular textual record representing a query; (iii) determining, by way of the ML clustering model and based on the similarity metric, that the particular textual record does not fit into any of the clusters; and (iv) in response to determining that the particular textual record does not fit into any of the clusters, adding the particular textual record to the residual set of the textual records 
     In a fourth example embodiment, an article of manufacture may include a non-transitory computer-readable medium, having stored thereon program instructions that, upon execution by a computing system, cause the computing system to perform operations in accordance with the first, second, or third example embodiments. 
     In a fifth example embodiment, a computing system may include at least one processor, as well as memory and program instructions. The program instructions may be stored in the memory, and upon execution by the at least one processor, cause the computing system to perform operations in accordance with the first, second, or third example embodiments. 
     In a sixth example embodiment, a system may include various means for carrying out each of the operations of the first, second, or third example embodiments. 
     These, as well as other embodiments, aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, this summary and other descriptions and figures provided herein are intended to illustrate embodiments by way of example only and, as such, that numerous variations are possible. For instance, structural elements and process steps can be rearranged, combined, distributed, eliminated, or otherwise changed, while remaining within the scope of the embodiments as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a schematic drawing of a computing device, in accordance with example embodiments. 
         FIG.  2    illustrates a schematic drawing of a server device cluster, in accordance with example embodiments. 
         FIG.  3    depicts a remote network management architecture, in accordance with example embodiments. 
         FIG.  4    depicts a communication environment involving a remote network management architecture, in accordance with example embodiments. 
         FIG.  5 A  depicts another communication environment involving a remote network management architecture, in accordance with example embodiments. 
         FIG.  5 B  is a flow chart, in accordance with example embodiments. 
         FIG.  6    depicts an incident report, in accordance with example embodiments. 
         FIG.  7    depicts a database query architecture, in accordance with example embodiments. 
         FIG.  8 A  depicts an artificial neural network (ANN) configured for learning the contextual meanings of words, in accordance with example embodiments. 
         FIG.  8 B  depicts a set of training data for the ANN of  FIG.  9 A , in accordance with example embodiments. 
         FIG.  9 A  depicts an artificial neural network (ANN) configured for learning the contextual meanings of words, in accordance with example embodiments. 
         FIG.  9 B  depicts a set of training data for the ANN of  FIG.  9 A , in accordance with example embodiments. 
         FIG.  10 A  depicts training an ANN for paragraph vectors, in accordance with example embodiments. 
         FIG.  10 B  depicts training an ANN for paragraph vectors, in accordance with example embodiments. 
         FIG.  10 C  depicts training an ANN for paragraph vectors, in accordance with example embodiments. 
         FIG.  10 D  depicts using a trained ANN to determine the paragraph vector of a previously unseen paragraph, in accordance with example embodiments. 
         FIG.  11 A  depicts the locations of records in a two-dimensional space, in accordance with example embodiments. 
         FIG.  11 B  depicts the records of  FIG.  11 A , having been grouped into clusters, in accordance with example embodiments. 
         FIG.  11 C  depicts the records of  FIG.  11 A , having been grouped into clusters, in accordance with example embodiments. 
         FIG.  11 D  depicts the records of  FIG.  11 A , having been grouped into clusters, in accordance with example embodiments. 
         FIG.  11 E  depicts the records of  FIG.  11 A , having been grouped into clusters, in accordance with example embodiments. 
         FIG.  11 F  depicts the records of  FIG.  11 A , having been grouped into clusters, in accordance with example embodiments. 
         FIG.  12 A  depicts the locations of records in a two-dimensional space, in accordance with example embodiments. 
         FIG.  12 B  depicts the records of  FIG.  12 A , having been grouped into clusters, with some of the records not belonging to any of the clusters, in accordance with example embodiments. 
         FIG.  12 C  depicts the records of  FIG.  12 A , having been grouped into clusters, with some of the records not belonging to any of the clusters, and a set of additional records, in accordance with example embodiments. 
         FIG.  12 D  depicts the records of  FIG.  12 C , having been grouped into clusters, with some of the records not belonging to any of the clusters, in accordance with example embodiments. 
         FIG.  13    is a flow chart, in accordance with example embodiments. 
         FIG.  14    is a flow chart, in accordance with example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Example methods, devices, and systems are described herein. It should be understood that the words “example” and “exemplary” are used herein to mean “serving as an example, instance, or illustration.” Any embodiment or feature described herein as being an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or features unless stated as such. Thus, other embodiments can be utilized and other changes can be made without departing from the scope of the subject matter presented herein. 
     Accordingly, the example embodiments described herein are not meant to be limiting. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations. For example, the separation of features into “client” and “server” components may occur in a number of ways. 
     Further, unless context suggests otherwise, the features illustrated in each of the figures may be used in combination with one another. Thus, the figures should be generally viewed as component aspects of one or more overall embodiments, with the understanding that not all illustrated features are necessary for each embodiment. 
     Additionally, any enumeration of elements, blocks, or steps in this specification or the claims is for purposes of clarity. Thus, such enumeration should not be interpreted to require or imply that these elements, blocks, or steps adhere to a particular arrangement or are carried out in a particular order. 
     I. Introduction 
     A large enterprise is a complex entity with many interrelated operations. Some of these are found across the enterprise, such as human resources (HR), supply chain, information technology (IT), and finance. However, each enterprise also has its own unique operations that provide essential capabilities and/or create competitive advantages. 
     To support widely-implemented operations, enterprises typically use off-the-shelf software applications, such as customer relationship management (CRM) and human capital management (HCM) packages. However, they may also need custom software applications to meet their own unique requirements. A large enterprise often has dozens or hundreds of these custom software applications. Nonetheless, the advantages provided by the embodiments herein are not limited to large enterprises and may be applicable to an enterprise, or any other type of organization, of any size. 
     Many such software applications are developed by individual departments within the enterprise. These range from simple spreadsheets to custom-built software tools and databases. But the proliferation of siloed custom software applications has numerous disadvantages. It negatively impacts an enterprise’s ability to run and grow its operations, innovate, and meet regulatory requirements. The enterprise may find it difficult to integrate, streamline and enhance its operations due to lack of a single system that unifies its subsystems and data. 
     To efficiently create custom applications, enterprises would benefit from a remotely-hosted application platform that eliminates unnecessary development complexity. The goal of such a platform would be to reduce time-consuming, repetitive application development tasks so that software engineers and individuals in other roles can focus on developing unique, high-value features. 
     In order to achieve this goal, the concept of Application Platform as a Service (aPaaS) is introduced, to intelligently automate workflows throughout the enterprise. An aPaaS system is hosted remotely from the enterprise, but may access data, applications, and services within the enterprise by way of secure connections. Such an aPaaS system may have a number of advantageous capabilities and characteristics. These advantages and characteristics may be able to improve the enterprise’s operations and workflow for IT, HR, CRM, customer service, application development, and security. 
     The aPaaS system may support development and execution of model-view-controller (MVC) applications. MVC applications divide their functionality into three interconnected parts (model, view, and controller) in order to isolate representations of information from the manner in which the information is presented to the user, thereby allowing for efficient code reuse and parallel development. These applications may be web-based, and offer create, read, update, delete (CRUD) capabilities. This allows new applications to be built on a common application infrastructure. 
     The aPaaS system may support standardized application components, such as a standardized set of widgets for graphical user interface (GUI) development. In this way, applications built using the aPaaS system have a common look and feel. Other software components and modules may be standardized as well. In some cases, this look and feel can be branded or skinned with an enterprise’s custom logos and/or color schemes. 
     The aPaaS system may support the ability to configure the behavior of applications using metadata. This allows application behaviors to be rapidly adapted to meet specific needs. Such an approach reduces development time and increases flexibility. Further, the aPaaS system may support GUI tools that facilitate metadata creation and management, thus reducing errors in the metadata. 
     The aPaaS system may support clearly-defined interfaces between applications, so that software developers can avoid unwanted inter-application dependencies. Thus, the aPaaS system may implement a service layer in which persistent state information and other data are stored. 
     The aPaaS system may support a rich set of integration features so that the applications thereon can interact with legacy applications and third-party applications. For instance, the aPaaS system may support a custom employee-onboarding system that integrates with legacy HR, IT, and accounting systems. 
     The aPaaS system may support enterprise-grade security. Furthermore, since the aPaaS system may be remotely hosted, it should also utilize security procedures when it interacts with systems in the enterprise or third-party networks and services hosted outside of the enterprise. For example, the aPaaS system may be configured to share data amongst the enterprise and other parties to detect and identify common security threats. 
     Other features, functionality, and advantages of an aPaaS system may exist. This description is for purpose of example and is not intended to be limiting. 
     As an example of the aPaaS development process, a software developer may be tasked to create a new application using the aPaaS system. First, the developer may define the data model, which specifies the types of data that the application uses and the relationships therebetween. Then, via a GUI of the aPaaS system, the developer enters (e.g., uploads) the data model. The aPaaS system automatically creates all of the corresponding database tables, fields, and relationships, which can then be accessed via an object-oriented services layer. 
     In addition, the aPaaS system can also build a fully-functional MVC application with client-side interfaces and server-side CRUD logic. This generated application may serve as the basis of further development for the user. Advantageously, the developer does not have to spend a large amount of time on basic application functionality. Further, since the application may be web-based, it can be accessed from any Internet-enabled client device. Alternatively or additionally, a local copy of the application may be able to be accessed, for instance, when Internet service is not available. 
     The aPaaS system may also support a rich set of pre-defined functionality that can be added to applications. These features include support for searching, email, templating, workflow design, reporting, analytics, social media, scripting, mobile-friendly output, and customized GUIs. 
     The following embodiments describe architectural and functional aspects of example aPaaS systems, as well as the features and advantages thereof. 
     II. Example Computing Devices and Cloud-Based Computing Environments 
       FIG.  1    is a simplified block diagram exemplifying a computing device  100 , illustrating some of the components that could be included in a computing device arranged to operate in accordance with the embodiments herein. Computing device  100  could be a client device (e.g., a device actively operated by a user), a server device (e.g., a device that provides computational services to client devices), or some other type of computational platform. Some server devices may operate as client devices from time to time in order to perform particular operations, and some client devices may incorporate server features. 
     In this example, computing device  100  includes processor  102 , memory  104 , network interface  106 , and an input / output unit  108 , all of which may be coupled by a system bus  110  or a similar mechanism. In some embodiments, computing device  100  may include other components and/or peripheral devices (e.g., detachable storage, printers, and so on). 
     Processor  102  may be one or more of any type of computer processing element, such as a central processing unit (CPU), a co-processor (e.g., a mathematics, graphics, or encryption co-processor), a digital signal processor (DSP), a network processor, and/or a form of integrated circuit or controller that performs processor operations. In some cases, processor  102  may be one or more single-core processors. In other cases, processor  102  may be one or more multi-core processors with multiple independent processing units. Processor  102  may also include register memory for temporarily storing instructions being executed and related data, as well as cache memory for temporarily storing recently-used instructions and data. 
     Memory  104  may be any form of computer-usable memory, including but not limited to random access memory (RAM), read-only memory (ROM), and non-volatile memory (e.g., flash memory, hard disk drives, solid state drives, compact discs (CDs), digital video discs (DVDs), and/or tape storage). Thus, memory  104  represents both main memory units, as well as long-term storage. Other types of memory may include biological memory. 
     Memory  104  may store program instructions and/or data on which program instructions may operate. By way of example, memory  104  may store these program instructions on a non-transitory, computer-readable medium, such that the instructions are executable by processor  102  to carry out any of the methods, processes, or operations disclosed in this specification or the accompanying drawings. 
     As shown in  FIG.  1   , memory  104  may include firmware  104 A, kernel  104 B, and/or applications  104 C. Firmware  104 A may be program code used to boot or otherwise initiate some or all of computing device  100 . Kernel  104 B may be an operating system, including modules for memory management, scheduling and management of processes, input / output, and communication. Kernel  104 B may also include device drivers that allow the operating system to communicate with the hardware modules (e.g., memory units, networking interfaces, ports, and busses), of computing device  100 . Applications  104 C  may be one or more user-space software programs, such as web browsers or email clients, as well as any software libraries used by these programs. Memory  104  may also store data used by these and other programs and applications. 
     Network interface  106  may take the form of one or more wireline interfaces, such as Ethernet (e.g., Fast Ethernet, Gigabit Ethernet, and so on). Network interface  106  may also support communication over one or more non-Ethernet media, such as coaxial cables or power lines, or over wide-area media, such as Synchronous Optical Networking (SONET) or digital subscriber line (DSL) technologies. Network interface  106  may additionally take the form of one or more wireless interfaces, such as IEEE 802.11 (Wifi), BLUETOOTH®, global positioning system (GPS), or a wide-area wireless interface. However, other forms of physical layer interfaces and other types of standard or proprietary communication protocols may be used over network interface  106 . Furthermore, network interface  106  may comprise multiple physical interfaces. For instance, some embodiments of computing device  100  may include Ethernet, BLUETOOTH®, and Wifi interfaces. 
     Input / output unit  108  may facilitate user and peripheral device interaction with computing device  100 . Input / output unit  108  may include one or more types of input devices, such as a keyboard, a mouse, a touch screen, and so on. Similarly, input / output unit  108  may include one or more types of output devices, such as a screen, monitor, printer, and/or one or more light emitting diodes (LEDs). Additionally or alternatively, computing device  100  may communicate with other devices using a universal serial bus (USB) or high-definition multimedia interface (HDMI) port interface, for example. 
     In some embodiments, one or more computing devices like computing device  100  may be deployed to support an aPaaS architecture. The exact physical location, connectivity, and configuration of these computing devices may be unknown and/or unimportant to client devices. Accordingly, the computing devices may be referred to as “cloud-based” devices that may be housed at various remote data center locations. 
       FIG.  2    depicts a cloud-based server cluster  200  in accordance with example embodiments. In  FIG.  2   , operations of a computing device (e.g., computing device  100 ) may be distributed between server devices  202 , data storage  204 , and routers  206 , all of which may be connected by local cluster network  208 . The number of server devices  202 , data storages  204 , and routers  206  in server cluster  200  may depend on the computing task(s) and/or applications assigned to server cluster  200 . 
     For example, server devices  202  can be configured to perform various computing tasks of computing device  100 . Thus, computing tasks can be distributed among one or more of server devices  202 . To the extent that these computing tasks can be performed in parallel, such a distribution of tasks may reduce the total time to complete these tasks and return a result. For purpose of simplicity, both server cluster  200  and individual server devices  202  may be referred to as a “server device.” This nomenclature should be understood to imply that one or more distinct server devices, data storage devices, and cluster routers may be involved in server device operations. 
     Data storage  204  may be data storage arrays that include drive array controllers configured to manage read and write access to groups of hard disk drives and/or solid state drives. The drive array controllers, alone or in conjunction with server devices  202 , may also be configured to manage backup or redundant copies of the data stored in data storage  204  to protect against drive failures or other types of failures that prevent one or more of server devices  202  from accessing units of data storage  204 . Other types of memory aside from drives may be used. 
     Routers  206  may include networking equipment configured to provide internal and external communications for server cluster  200 . For example, routers  206  may include one or more packet-switching and/or routing devices (including switches and/or gateways) configured to provide (i) network communications between server devices  202  and data storage  204  via local cluster network  208 , and/or (ii) network communications between the server cluster  200  and other devices via communication link  210  to network  212 . 
     Additionally, the configuration of routers  206  can be based at least in part on the data communication requirements of server devices  202  and data storage  204 , the latency and throughput of the local cluster network  208 , the latency, throughput, and cost of communication link  210 , and/or other factors that may contribute to the cost, speed, fault-tolerance, resiliency, efficiency and/or other design goals of the system architecture. 
     As a possible example, data storage  204  may include any form of database, such as a structured query language (SQL) database. Various types of data structures may store the information in such a database, including but not limited to tables, arrays, lists, trees, and tuples. Furthermore, any databases in data storage  204  may be monolithic or distributed across multiple physical devices. 
     Server devices  202  may be configured to transmit data to and receive data from data storage  204 . This transmission and retrieval may take the form of SQL queries or other types of database queries, and the output of such queries, respectively. Additional text, images, video, and/or audio may be included as well. Furthermore, server devices  202  may organize the received data into web page representations. Such a representation may take the form of a markup language, such as the hypertext markup language (HTML), the extensible markup language (XML), or some other standardized or proprietary format. Moreover, server devices  202  may have the capability of executing various types of computerized scripting languages, such as but not limited to Perl, Python, PHP Hypertext Preprocessor (PHP), Active Server Pages (ASP), JAVASCRIPT®, and so on. Computer program code written in these languages may facilitate the providing of web pages to client devices, as well as client device interaction with the web pages. 
     III. Example Remote Network Management Architecture 
       FIG.  3    depicts a remote network management architecture, in accordance with example embodiments. This architecture includes three main components, managed network  300 , remote network management platform  320 , and third-party networks  340 , all connected by way of Internet  350 . 
     Managed network  300  may be, for example, an enterprise network used by an entity for computing and communications tasks, as well as storage of data. Thus, managed network  300  may include client devices  302 , server devices  304 , routers  306 , virtual machines  308 , firewall  310 , and/or proxy servers  312 . Client devices  302  may be embodied by computing device  100 , server devices  304  may be embodied by computing device  100  or server cluster  200 , and routers  306  may be any type of router, switch, or gateway. 
     Virtual machines  308  may be embodied by one or more of computing device  100  or server cluster  200 . In general, a virtual machine is an emulation of a computing system, and mimics the functionality (e.g., processor, memory, and communication resources) of a physical computer. One physical computing system, such as server cluster  200 , may support up to thousands of individual virtual machines. In some embodiments, virtual machines  308  may be managed by a centralized server device or application that facilitates allocation of physical computing resources to individual virtual machines, as well as performance and error reporting. Enterprises often employ virtual machines in order to allocate computing resources in an efficient, as needed fashion. Providers of virtualized computing systems include VMWARE® and MICROSOFT®. 
     Firewall  310  may be one or more specialized routers or server devices that protect managed network  300  from unauthorized attempts to access the devices, applications, and services therein, while allowing authorized communication that is initiated from managed network  300 . Firewall  310  may also provide intrusion detection, web filtering, virus scanning, application-layer gateways, and other applications or services. In some embodiments not shown in  FIG.  3   , managed network  300  may include one or more virtual private network (VPN) gateways with which it communicates with remote network management platform  320  (see below). 
     Managed network  300  may also include one or more proxy servers  312 . An embodiment of proxy servers  312  may be a server device that facilitates communication and movement of data between managed network  300 , remote network management platform  320 , and third-party networks  340 . In particular, proxy servers  312  may be able to establish and maintain secure communication sessions with one or more computational instances of remote network management platform  320 . By way of such a session, remote network management platform  320  may be able to discover and manage aspects of the architecture and configuration of managed network  300  and its components. Possibly with the assistance of proxy servers  312 , remote network management platform  320  may also be able to discover and manage aspects of third-party networks  340  that are used by managed network  300 . 
     Firewalls, such as firewall  310 , typically deny all communication sessions that are incoming by way of Internet  350 , unless such a session was ultimately initiated from behind the firewall (i.e., from a device on managed network  300 ) or the firewall has been explicitly configured to support the session. By placing proxy servers  312  behind firewall  310  (e.g., within managed network  300  and protected by firewall  310 ), proxy servers  312  may be able to initiate these communication sessions through firewall  310 . Thus, firewall  310  might not have to be specifically configured to support incoming sessions from remote network management platform  320 , thereby avoiding potential security risks to managed network  300 . 
     In some cases, managed network  300  may consist of a few devices and a small number of networks. In other deployments, managed network  300  may span multiple physical locations and include hundreds of networks and hundreds of thousands of devices. Thus, the architecture depicted in  FIG.  3    is capable of scaling up or down by orders of magnitude. 
     Furthermore, depending on the size, architecture, and connectivity of managed network  300 , a varying number of proxy servers  312  may be deployed therein. For example, each one of proxy servers  312  may be responsible for communicating with remote network management platform  320  regarding a portion of managed network  300 . Alternatively or additionally, sets of two or more proxy servers may be assigned to such a portion of managed network  300  for purposes of load balancing, redundancy, and/or high availability. 
     Remote network management platform  320  is a hosted environment that provides aPaaS services to users, particularly to the operators of managed network  300 . These services may take the form of web-based portals, for instance. Thus, a user can securely access remote network management platform  320  from, for instance, client devices  302 , or potentially from a client device outside of managed network  300 . By way of the web-based portals, users may design, test, and deploy applications, generate reports, view analytics, and perform other tasks. 
     As shown in  FIG.  3   , remote network management platform  320  includes four computational instances  322 ,  324 ,  326 , and  328 . Each of these instances may represent one or more server devices and/or one or more databases that provide a set of web portals, services, and applications (e.g., a wholly-functioning aPaaS system) available to a particular customer. In some cases, a single customer may use multiple computational instances. For example, managed network  300  may be an enterprise customer of remote network management platform  320 , and may use computational instances  322 ,  324 , and  326 . The reason for providing multiple instances to one customer is that the customer may wish to independently develop, test, and deploy its applications and services. Thus, computational instance  322  may be dedicated to application development related to managed network  300 , computational instance  324  may be dedicated to testing these applications, and computational instance  326  may be dedicated to the live operation of tested applications and services. A computational instance may also be referred to as a hosted instance, a remote instance, a customer instance, or by some other designation. Any application deployed onto a computational instance may be a scoped application, in that its access to databases within the computational instance can be restricted to certain elements therein (e.g., one or more particular database tables or particular rows with one or more database tables). 
     For purpose of clarity, the disclosure herein refers to the physical hardware, software, and arrangement thereof as a “computational instance.” Note that users may colloquially refer to the graphical user interfaces provided thereby as “instances.” But unless it is defined otherwise herein, a “computational instance” is a computing system disposed within remote network management platform  320 . 
     The multi-instance architecture of remote network management platform  320  is in contrast to conventional multi-tenant architectures, over which multi-instance architectures exhibit several advantages. In multi-tenant architectures, data from different customers (e.g., enterprises) are comingled in a single database. While these customers’ data are separate from one another, the separation is enforced by the software that operates the single database. As a consequence, a security breach in this system may impact all customers’ data, creating additional risk, especially for entities subject to governmental, healthcare, and/or financial regulation. Furthermore, any database operations that impact one customer will likely impact all customers sharing that database. Thus, if there is an outage due to hardware or software errors, this outage affects all such customers. Likewise, if the database is to be upgraded to meet the needs of one customer, it will be unavailable to all customers during the upgrade process. Often, such maintenance windows will be long, due to the size of the shared database. 
     In contrast, the multi-instance architecture provides each customer with its own database in a dedicated computing instance. This prevents comingling of customer data, and allows each instance to be independently managed. For example, when one customer’s instance experiences an outage due to errors or an upgrade, other computational instances are not impacted. Maintenance down time is limited because the database only contains one customer’s data. Further, the simpler design of the multi-instance architecture allows redundant copies of each customer database and instance to be deployed in a geographically diverse fashion. This facilitates high availability, where the live version of the customer’s instance can be moved when faults are detected or maintenance is being performed. 
     In some embodiments, remote network management platform  320  may include one or more central instances, controlled by the entity that operates this platform. Like a computational instance, a central instance may include some number of physical or virtual servers and database devices. Such a central instance may serve as a repository for data that can be shared amongst at least some of the computational instances. For instance, definitions of common security threats that could occur on the computational instances, software packages that are commonly discovered on the computational instances, and/or an application store for applications that can be deployed to the computational instances may reside in a central instance. Computational instances may communicate with central instances by way of well-defined interfaces in order to obtain this data. 
     In order to support multiple computational instances in an efficient fashion, remote network management platform  320  may implement a plurality of these instances on a single hardware platform. For example, when the aPaaS system is implemented on a server cluster such as server cluster  200 , it may operate a virtual machine that dedicates varying amounts of computational, storage, and communication resources to instances. But full virtualization of server cluster  200  might not be necessary, and other mechanisms may be used to separate instances. In some examples, each instance may have a dedicated account and one or more dedicated databases on server cluster  200 . Alternatively, computational instance  322  may span multiple physical devices. 
     In some cases, a single server cluster of remote network management platform  320  may support multiple independent enterprises. Furthermore, as described below, remote network management platform  320  may include multiple server clusters deployed in geographically diverse data centers in order to facilitate load balancing, redundancy, and/or high availability. 
     Third-party networks  340  may be remote server devices (e.g., a plurality of server clusters such as server cluster  200 ) that can be used for outsourced computational, data storage, communication, and service hosting operations. These servers may be virtualized (i.e., the servers may be virtual machines). Examples of third-party networks  340  may include AMAZON WEB SERVICES® and MICROSOFT® AZURE®. Like remote network management platform  320 , multiple server clusters supporting third-party networks  340  may be deployed at geographically diverse locations for purposes of load balancing, redundancy, and/or high availability. 
     Managed network  300  may use one or more of third-party networks  340  to deploy applications and services to its clients and customers. For instance, if managed network  300  provides online music streaming services, third-party networks  340  may store the music files and provide web interface and streaming capabilities. In this way, the enterprise of managed network  300  does not have to build and maintain its own servers for these operations. 
     Remote network management platform  320  may include modules that integrate with third-party networks  340  to expose virtual machines and managed services therein to managed network  300 . The modules may allow users to request virtual resources and provide flexible reporting for third-party networks  340 . In order to establish this functionality, a user from managed network  300  might first establish an account with third-party networks  340 , and request a set of associated resources. Then, the user may enter the account information into the appropriate modules of remote network management platform  320 . These modules may then automatically discover the manageable resources in the account, and also provide reports related to usage, performance, and billing. 
     Internet  350  may represent a portion of the global Internet. However, Internet  350  may alternatively represent a different type of network, such as a private wide-area or local-area packet-switched network. 
       FIG.  4    further illustrates the communication environment between managed network  300  and computational instance  322 , and introduces additional features and alternative embodiments. In  FIG.  4   , computational instance  322  is replicated across data centers  400 A and  400 B. These data centers may be geographically distant from one another, perhaps in different cities or different countries. Each data center includes support equipment that facilitates communication with managed network  300 , as well as remote users. 
     In data center  400 A, network traffic to and from external devices flows either through VPN gateway  402 A or firewall  404 A. VPN gateway  402 A may be peered with VPN gateway  412  of managed network  300  by way of a security protocol such as Internet Protocol Security (IPSEC) or Transport Layer Security (TLS). Firewall  404 A may be configured to allow access from authorized users, such as user  414  and remote user  416 , and to deny access to unauthorized users. By way of firewall  404 A, these users may access computational instance  322 , and possibly other computational instances. Load balancer  406 A may be used to distribute traffic amongst one or more physical or virtual server devices that host computational instance  322 . Load balancer  406 A may simplify user access by hiding the internal configuration of data center  400 A, (e.g., computational instance  322 ) from client devices. For instance, if computational instance  322  includes multiple physical or virtual computing devices that share access to multiple databases, load balancer  406 A may distribute network traffic and processing tasks across these computing devices and databases so that no one computing device or database is significantly busier than the others. In some embodiments, computational instance  322  may include VPN gateway  402 A, firewall  404 A, and load balancer  406 A. 
     Data center  400 B may include its own versions of the components in data center  400 A. Thus, VPN gateway  402 B, firewall  404 B, and load balancer  406 B may perform the same or similar operations as VPN gateway  402 A, firewall  404 A, and load balancer  406 A, respectively. Further, by way of real-time or near-real-time database replication and/or other operations, computational instance  322  may exist simultaneously in data centers  400 A and  400 B. 
     Data centers  400 A and  400 B as shown in  FIG.  4    may facilitate redundancy and high availability. In the configuration of  FIG.  4   , data center  400 A is active and data center  400 B is passive. Thus, data center  400 A is serving all traffic to and from managed network  300 , while the version of computational instance  322  in data center  400 B is being updated in near-real-time. Other configurations, such as one in which both data centers are active, may be supported. 
     Should data center  400 A fail in some fashion or otherwise become unavailable to users, data center  400 B can take over as the active data center. For example, domain name system (DNS) servers that associate a domain name of computational instance  322  with one or more Internet Protocol (IP) addresses of data center  400 A may re-associate the domain name with one or more IP addresses of data center  400 B. After this re-association completes (which may take less than one second or several seconds), users may access computational instance  322  by way of data center  400 B. 
       FIG.  4    also illustrates a possible configuration of managed network  300 . As noted above, proxy servers  312  and user  414  may access computational instance  322  through firewall  310 . Proxy servers  312  may also access configuration items  410 . In  FIG.  4   , configuration items  410  may refer to any or all of client devices  302 , server devices  304 , routers  306 , and virtual machines  308 , any applications or services executing thereon, as well as relationships between devices, applications, and services. Thus, the term “configuration items” may be shorthand for any physical or virtual device, or any application or service remotely discoverable or managed by computational instance  322 , or relationships between discovered devices, applications, and services. Configuration items may be represented in a configuration management database (CMDB) of computational instance  322 . 
     As noted above, VPN gateway  412  may provide a dedicated VPN to VPN gateway  402 A. Such a VPN may be helpful when there is a significant amount of traffic between managed network  300  and computational instance  322 , or security policies otherwise suggest or require use of a VPN between these sites. In some embodiments, any device in managed network  300  and/or computational instance  322  that directly communicates via the VPN is assigned a public IP address. Other devices in managed network  300  and/or computational instance  322  may be assigned private IP addresses (e.g., IP addresses selected from the 10.0.0.0 - 10.255.255.255 or 192.168.0.0 - 192.168.255.255 ranges, represented in shorthand as subnets 10.0.0.0/8 and 192.168.0.0/16, respectively). 
     IV. Example Device, Application, and Service Discovery 
     In order for remote network management platform  320  to administer the devices, applications, and services of managed network  300 , remote network management platform  320  may first determine what devices are present in managed network  300 , the configurations and operational statuses of these devices, and the applications and services provided by the devices, and well as the relationships between discovered devices, applications, and services. As noted above, each device, application, service, and relationship may be referred to as a configuration item. The process of defining configuration items within managed network  300  is referred to as discovery, and may be facilitated at least in part by proxy servers  312 . 
     For purpose of the embodiments herein, an “application” may refer to one or more processes, threads, programs, client modules, server modules, or any other software that executes on a device or group of devices. A “service” may refer to a high-level capability provided by multiple applications executing on one or more devices working in conjunction with one another. For example, a high-level web service may involve multiple web application server threads executing on one device and accessing information from a database application that executes on another device. 
       FIG.  5 A  provides a logical depiction of how configuration items can be discovered, as well as how information related to discovered configuration items can be stored. For sake of simplicity, remote network management platform  320 , third-party networks  340 , and Internet  350  are not shown. 
     In  FIG.  5 A , CMDB  500  and task list  502  are stored within computational instance  322 . Computational instance  322  may transmit discovery commands to proxy servers  312 . In response, proxy servers  312  may transmit probes to various devices, applications, and services in managed network  300 . These devices, applications, and services may transmit responses to proxy servers  312 , and proxy servers  312  may then provide information regarding discovered configuration items to CMDB  500  for storage therein. Configuration items stored in CMDB  500  represent the environment of managed network  300 . 
     Task list  502  represents a list of activities that proxy servers  312  are to perform on behalf of computational instance  322 . As discovery takes place, task list  502  is populated. Proxy servers  312  repeatedly query task list  502 , obtain the next task therein, and perform this task until task list  502  is empty or another stopping condition has been reached. 
     To facilitate discovery, proxy servers  312  may be configured with information regarding one or more subnets in managed network  300  that are reachable by way of proxy servers  312 . For instance, proxy servers  312  may be given the IP address range 192.168.0/24 as a subnet. Then, computational instance  322  may store this information in CMDB  500  and place tasks in task list  502  for discovery of devices at each of these addresses. 
       FIG.  5 A  also depicts devices, applications, and services in managed network  300  as configuration items  504 ,  506 ,  508 ,  510 , and  512 . As noted above, these configuration items represent a set of physical and/or virtual devices (e.g., client devices, server devices, routers, or virtual machines), applications executing thereon (e.g., web servers, email servers, databases, or storage arrays), relationships therebetween, as well as services that involve multiple individual configuration items. 
     Placing the tasks in task list  502  may trigger or otherwise cause proxy servers  312  to begin discovery. Alternatively or additionally, discovery may be manually triggered or automatically triggered based on triggering events (e.g., discovery may automatically begin once per day at a particular time). 
     In general, discovery may proceed in four logical phases: scanning, classification, identification, and exploration. Each phase of discovery involves various types of probe messages being transmitted by proxy servers  312  to one or more devices in managed network  300 . The responses to these probes may be received and processed by proxy servers  312 , and representations thereof may be transmitted to CMDB  500 . Thus, each phase can result in more configuration items being discovered and stored in CMDB  500 . 
     In the scanning phase, proxy servers  312  may probe each IP address in the specified range of IP addresses for open Transmission Control Protocol (TCP) and/or User Datagram Protocol (UDP) ports to determine the general type of device. The presence of such open ports at an IP address may indicate that a particular application is operating on the device that is assigned the IP address, which in turn may identify the operating system used by the device. For example, if TCP port  135  is open, then the device is likely executing a WINDOWS® operating system. Similarly, if TCP port  22  is open, then the device is likely executing a UNIX® operating system, such as LINUX®. If UDP port  161  is open, then the device may be able to be further identified through the Simple Network Management Protocol (SNMP). Other possibilities exist. Once the presence of a device at a particular IP address and its open ports have been discovered, these configuration items are saved in CMDB  500 . 
     In the classification phase, proxy servers  312  may further probe each discovered device to determine the version of its operating system. The probes used for a particular device are based on information gathered about the devices during the scanning phase. For example, if a device is found with TCP port  22  open, a set of UNIX®-specific probes may be used. Likewise, if a device is found with TCP port  135  open, a set of WINDOWS®-specific probes may be used. For either case, an appropriate set of tasks may be placed in task list  502  for proxy servers  312  to carry out. These tasks may result in proxy servers  312  logging on, or otherwise accessing information from the particular device. For instance, if TCP port  22  is open, proxy servers  312  may be instructed to initiate a Secure Shell (SSH) connection to the particular device and obtain information about the operating system thereon from particular locations in the file system. Based on this information, the operating system may be determined. As an example, a UNIX® device with TCP port  22  open may be classified as AIX®, HPUX, LINUX®, MACOS®, or SOLARIS®. This classification information may be stored as one or more configuration items in CMDB  500 . 
     In the identification phase, proxy servers  312  may determine specific details about a classified device. The probes used during this phase may be based on information gathered about the particular devices during the classification phase. For example, if a device was classified as LINUX®, a set of LINUX®-specific probes may be used. Likewise, if a device was classified as WINDOWS® 2012, as a set of WINDOWS®-2012-specific probes may be used. As was the case for the classification phase, an appropriate set of tasks may be placed in task list  502  for proxy servers  312  to carry out. These tasks may result in proxy servers  312  reading information from the particular device, such as basic input / output system (BIOS) information, serial numbers, network interface information, media access control address(es) assigned to these network interface(s), IP address(es) used by the particular device and so on. This identification information may be stored as one or more configuration items in CMDB  500 . 
     In the exploration phase, proxy servers  312  may determine further details about the operational state of a classified device. The probes used during this phase may be based on information gathered about the particular devices during the classification phase and/or the identification phase. Again, an appropriate set of tasks may be placed in task list  502  for proxy servers  312  to carry out. These tasks may result in proxy servers  312  reading additional information from the particular device, such as processor information, memory information, lists of running processes (applications), and so on. Once more, the discovered information may be stored as one or more configuration items in CMDB  500 . 
     Running discovery on a network device, such as a router, may utilize SNMP. Instead of or in addition to determining a list of running processes or other application-related information, discovery may determine additional subnets known to the router and the operational state of the router’s network interfaces (e.g., active, inactive, queue length, number of packets dropped, etc.). The IP addresses of the additional subnets may be candidates for further discovery procedures. Thus, discovery may progress iteratively or recursively. 
     Once discovery completes, a snapshot representation of each discovered device, application, and service is available in CMDB  500 . For example, after discovery, operating system version, hardware configuration and network configuration details for client devices, server devices, and routers in managed network  300 , as well as applications executing thereon, may be stored. This collected information may be presented to a user in various ways to allow the user to view the hardware composition and operational status of devices, as well as the characteristics of services that span multiple devices and applications. 
     Furthermore, CMDB  500  may include entries regarding dependencies and relationships between configuration items. More specifically, an application that is executing on a particular server device, as well as the services that rely on this application, may be represented as such in CMDB  500 . For instance, suppose that a database application is executing on a server device, and that this database application is used by a new employee onboarding service as well as a payroll service. Thus, if the server device is taken out of operation for maintenance, it is clear that the employee onboarding service and payroll service will be impacted. Likewise, the dependencies and relationships between configuration items may be able to represent the services impacted when a particular router fails. 
     In general, dependencies and relationships between configuration items may be displayed on a web-based interface and represented in a hierarchical fashion. Thus, adding, changing, or removing such dependencies and relationships may be accomplished by way of this interface. 
     Furthermore, users from managed network  300  may develop workflows that allow certain coordinated activities to take place across multiple discovered devices. For instance, an IT workflow might allow the user to change the common administrator password to all discovered LINUX® devices in a single operation. 
     In order for discovery to take place in the manner described above, proxy servers  312 , CMDB  500 , and/or one or more credential stores may be configured with credentials for one or more of the devices to be discovered. Credentials may include any type of information needed in order to access the devices. These may include userid / password pairs, certificates, and so on. In some embodiments, these credentials may be stored in encrypted fields of CMDB  500 . Proxy servers  312  may contain the decryption key for the credentials so that proxy servers  312  can use these credentials to log on to or otherwise access devices being discovered. 
     The discovery process is depicted as a flow chart in  FIG.  5 B . At block  520 , the task list in the computational instance is populated, for instance, with a range of IP addresses. At block  522 , the scanning phase takes place. Thus, the proxy servers probe the IP addresses for devices using these IP addresses, and attempt to determine the operating systems that are executing on these devices. At block  524 , the classification phase takes place. The proxy servers attempt to determine the operating system version of the discovered devices. At block  526 , the identification phase takes place. The proxy servers attempt to determine the hardware and/or software configuration of the discovered devices. At block  528 , the exploration phase takes place. The proxy servers attempt to determine the operational state and applications executing on the discovered devices. At block  530 , further editing of the configuration items representing the discovered devices and applications may take place. This editing may be automated and/or manual in nature. 
     The blocks represented in  FIG.  5 B  are for purpose of example. Discovery may be a highly configurable procedure that can have more or fewer phases, and the operations of each phase may vary. In some cases, one or more phases may be customized, or may otherwise deviate from the exemplary descriptions above. 
     V. Natural Language Processing of Text Queries 
     Natural language processing is a discipline that involves, among other activities, using computers to understand the structure and meaning of human language. This determined structure and meaning may be applicable to the processing of IT incidents, as described below. 
     Each incident may be represented as an incident report. While incident reports may exist in various formats and contain various types of information, an example incident report  600  is shown in  FIG.  6   . Incident report  600  consists of a number of fields in the left column, at least some of which are associated with values in the right column. 
     Field  602  identifies the originator of the incident, in this case Bob Smith. Field  604  identifies the time at which the incident was created, in this case 9:56AM on Feb. 7, 2018. Field  605  is a text string that provides a short description of the problem. Field  606  identifies the description of the problem, as provided by the originator. Thus, field  606  may be a free-form text string containing anywhere from a few words to several sentences or more. Field  608  is a categorization of the incident, in this case email. This categorization may be provided by the originator, the IT personnel to whom the incident is assigned, or automatically based on the context of the problem description field. 
     Field  610  identifies the IT personnel to whom the incident is assigned (if applicable), in this case Alice Jones. Field  612  identifies the status of the incident. The status may be one of “open,” “assigned,” “working,” or “resolved” for instance. Field  614  identifies how the incident was resolved (if applicable). This field may be filled out by the IT personnel to whom the incident is assigned or another individual. Field  616  identifies the time at which the incident was resolved, in this case 10:10AM on Feb. 7, 2018. Field  618  specifies the closure code of the incident (if applicable) and can take on values such as “closed (permanently)”, “closed (work around)”, “closed (cannot reproduce)”, etc. Field  620  identifies any additional notes added to the record, such as by the IT personnel to whom the incident is assigned. Field  622  identifies a link to an online article that may help users avoid having to address a similar issue in the future. 
     Incident report  600  is presented for purpose of example. Other types of incident reports may be used, and these reports may contain more, fewer, and/or different fields. 
     Incident reports, such as incident report  600 , may be created in various ways. For instance, by way of a web form, an email sent to a designated address, a voicemail box using speech-to-text conversion, and so on. These incident reports may be stored in an incident report database that can be queried. As an example, a query in the form of a text string could return one or more incident reports that contain the words in the text string. Additionally or alternatively, one or more elements of an incident report (e.g., a “short description” field) may be used to query a database of knowledgebase articles, other incident reports, or some other corpus of text. This may be done in order to identify other incident reports, resolved past incident reports, reports on the resolution of past problems, knowledgebase articles, or other information that may be relevant to the incident report in order to facilitate resolution of a problem represented in the incident report. 
     This process is illustrated in  FIG.  7   . A text query may be entered into web interface  700 . This web interface may be supplied by way of a computational instance of remote network management platform  320 . Web interface  700  converts the text query into a database query (e.g., an SQL query), and provides the SQL query to database  702 . This database may be CMDB  500  or some other database. Database  702  contains a number of incident reports with problem description fields as shown in  FIG.  6   . Regardless, database  702  conducts the query and returns matching results to web interface  700 . One or more such results may be returned. Web interface  700  provides these results as a web page. 
     For example, if the text query is “email”, web interface  700  may convert this query into an SQL query of database  702 . For example, the query may look at the problem description field of a table containing incident reports. Any such incident report that matches the query - i.e., includes the term “email” - may be provided in the query results. Thus, the incident reports with the problem descriptions of “My email client is not downloading new emails”, “Email crashed”, and “Can’t connect to email” may be provided, while the incident report with the problem description “VPN timed out” is not returned. 
     This matching technique is simplistic and has a number of drawbacks. It only considers the presence of the text of the query in the incidents. Thus, it does not consider contextual information, such as words appearing before and after the query text. Also, synonyms of the query text (e.g., “mail” or “message”) and misspellings of the query text (e.g., “emial”) would not return any results in this example. 
     Furthermore, deploying such a solution would involve use of an inefficient sparse matrix, with entries in one dimension for each word in the English language and entries in the other dimension for the problem description of each incident. While the exact number of English words is a matter of debate, there are at least 150,000 - 200,000, with less than about 20,000 in common use. Given that a busy IT department can have a database of tens of thousands of incidents, this matrix would be quite large and wasteful to store even if just the 20,000 most commonly used words are included. 
     Thus, the above methods of comparison may be replaced by and/or augmented with a variety of methods that compare the semantic content and/or context of text samples. These methods can improve a variety of machine learning techniques to facilitate natural language processing. Such techniques can include determining word and/or paragraph vectors from samples of text, applying artificial neural networks or other deep learning algorithms, sentiment analysis, or other techniques in order to determine a similarity between samples of text. For example, these or other natural language processing techniques can be applied to determine the similarity between one or more text fields of an incident report and other incident reports, resolved incident reports, knowledgebase articles, or other potentially relevant samples of text. 
     VI. Natural Language Processing of Text Queries Based on Semantic Content 
     The degree of similarity between two samples of text can be determined in a variety of ways. The two samples of text could be a text field of an incident report and a text field of another incident report, a text field of a resolved incident report, a knowledgebase article, or some other sample of text that may be relevant to the resolution, classification, or other aspects of an incident report. Additionally or alternatively, one or both of the samples could be segments of text within a larger sample of text. As noted above, a degree of overlap between the identities of words present in the two samples of text and/or a word matrix method could be used to determine the degree of similarity. Additionally or alternatively, one or more techniques of natural language processing could be applied to compare the samples of text such that the context or other semantic content of the texts affects the determined similarity value between the samples of text. 
     Such techniques may be applied to improve text query matching related to incident reports. These techniques may include a variety of machine learning algorithms that can be trained based on samples of text. The samples of text used for training can include past examples of incident reports, knowledgebase articles, or other text samples of the same nature as the text samples to which the trained model will be applied. This has the benefit of providing a model that has been uniquely adapted to the vocabulary, topics, and idiomatic word use common in its intended application. 
     Such techniques can include determining word and/or paragraph vectors from samples of text, applying ANNs or other deep learning algorithms, performing sentiment analysis, or other techniques in order to determine a similarity between samples of text, to group multiple samples of text together according to topic or content, to partition a sample of text into discrete internally-related segments, to determine statistical associations between words, or to perform some other language processing task. Below, a particular method for determining similarity values between samples of text using an ANN model that provides compact semantic representations of words and text strings is provided as a non-limiting example of such techniques. However, other techniques may be applied to generate similarity values between samples of text as applied elsewhere herein. In the discussion below, there are two approaches for training an ANN model to represent the sematic meanings of words: word vectors and paragraph vectors. These techniques may be combined with one another or with other techniques. 
     A. Word Vectors 
     A “word vector” may be determined for each word present in a corpus of text records such that words having similar meanings (or “semantic content”) are associated with word vectors that are near each other within a semantically encoded vector space. Such vectors may have dozens, hundreds, or more elements. These word vectors allow the underlying meaning of words to be compared or otherwise operated on by a computing device. Accordingly, the use of word vectors may allow for a significant improvement over simpler word list or word matrix methods. 
     Word vectors can be used to quickly and efficiently compare the overall semantic content of samples of text, allowing a similarity value between the samples of text to be determined. This can include determining a distance, a cosine similarity, or some other measure of similarity between the word vectors of the words in each of the text samples. For example, a mean of the word vectors in each of the text samples could be determined and a cosine similarity between the means then used as a measure of similarity between the text samples. Additionally or alternatively, the word vectors may be provided as input to an ANN, a support vector machine, a decision tree, or some other machine learning algorithm in order to perform sentiment analysis, to classify or cluster samples of text, to determine a level of similarity between samples of text, or to perform some other language processing task. 
     Word vectors may be determined for a set of words in a variety of ways. In an example, a matrix of the word vectors can be an input layer of an ANN. The ANN (including the matrix of word vectors) can then be trained with a large number of text strings from a database to determine the contextual relationships between words appearing in these text strings. Such an ANN  800  is shown in  FIG.  8 A . ANN  800  includes input layer  802 , which feeds into hidden layer  804 , which in turn feeds into output layer  806 . The number of nodes in input layer  802  and output layer  806  may be equivalent to the number of words in a pre-defined vocabulary or dictionary (e.g., 20,000, 50,000, or 100,000). The number of nodes in hidden layer  804  may be much smaller (e.g., 64 as shown in  FIG.  8 A , or other values such as 16, 32, 128, 512, 1024, etc.). 
     For each text string in the database, ANN  800  is trained with one or more arrangements of words. For instance, in  FIG.  8 B , ANN  800  is shown being trained with input word “email” and output (context) words “can’t”, “connect” and “to”. The output words serve as the ground truth output values to which the results produced by output layer  806  are compared. This arrangement reflects that “email” appears proximate to “can’t”, “connect” and “to” in a text string in database  702 . 
     In an implementation, this could be represented as node I 2  receiving an input of 1, and all other nodes in input layer  802  receiving an input of 0. Similarly, node O 1  is associated with a ground truth value of “can’t”, node O 2  is associated with a ground truth value of “connect”, and node O 3  is associated with a ground truth value of “to”. In the implementation, this could be represented as nodes O 1 , O 2 , and O 3  being associated with ground truth values of 1 and all other nodes in output layer  806  being associated with ground truth values of 0. The loss function may be a sum of squared errors, for example, between the outputs generated by output layer  806  in response to the input described above and a vector containing the ground truth values associated with the output layer nodes. 
     Other arrangements of this text string from database  702  may be used to train an ANN. For instance, as shown in Figure A the input word to input layer  902  of an ANN  900  may be “can’t” and the output words of output layer  906  may be “connect”, “to”, and “email.” In another example, as shown in  FIG.  9 B , the input word may be “connect” and the output words may be “can’t”, “to”, and “email.” 
     In general, these arrangements may be selected so that the output words are within w words of the input word (e.g., where w could be 1, 2, 3, 5, etc.), the output words are in the same sentence as the input word, the output words are in the same paragraph as the input word, and so on. Furthermore, various word arrangements of each text string in database  702  may be used to train ANN (e.g., ANN  800  or ANN  900 ). These text strings may be selected from short description field  605 , problem description field  606 , category field  608 , resolution field  614 , notes field  620 , and/or any other field or combination of fields in an incident report. 
     After an ANN (e.g.,  800 ,  900 ) is trained with these arrangements of text strings, the hidden layer (e.g.,  804 ,  904 ) of the ANN becomes a compact vector representation of the context and meaning of an input word. That is, the weightings from a particular node (e.g., I 3 ) in the input layer to the hidden layer represent the elements of the word vector of the word corresponding to the particular node (e.g., “can’t”). For example, assuming that ANN is fully-trained with a corpus of 10,000 or so text strings (though more or fewer text strings may be used), an input word of “email” may have a similar vector representation of an input word of “mail”. Intuitively, since hidden layer is all that ANN has to determine the context of an input word, if two words have similar contexts, then they are highly likely to have similar vector representations. 
     In some embodiments, an ANN can be trained with input words associated with the output nodes O 1 ... O n  and the output (context) words associated with input nodes Ii... I n . This arrangement may produce an identical or similar vector for hidden layer. 
     Furthermore, vectors generated in this fashion are additive. Thus, subtracting the vector representation of “mail” from the vector representation of “email” is expected to produce a vector with values close to 0. However, subtracting the vector representation of “VPN” from the vector representation of “email” is expected to produce a vector with higher values. In this manner, the model indicates that “email” and “mail” have closer meanings than “email” and “VPN”. 
     Once vector representations have been determined for all words of interest, linear and/or multiplicative aggregations of these vectors may be used to represent text strings. For instance, a vector for the text string “can’t connect to email” can be found by adding together the individual vectors for the words “can’t”, “connect”, “to”, and “email”. In some cases, an average or some other operation may be applied to the vectors for the words. This can be expressed below as the vector sum of m vectors v i  with each entry therein divided by m, where i = {1... m}. But other possibilities, such as weighted averages, exist.  
     
       
         
           
             
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     Regardless of how the aggregations are determined, this general technique allows vector representations for each text string in database  702  to be found. These vector representations may be stored in database  702  as well, either along with their associated text strings or separately. These vector representations can then be used to compare the text strings, cluster or group the text strings, train some other machine learning classifier, or to perform some other task. For example, a matching text string for a particularly query text may be determined by determining a cosine similarity or other similarity value between the vector representation of the query text and the stored vector representations of samples of text in the database  702 . 
     The comparison may identify one or more text string vectors from database  702  that “match” in this fashion. In some cases this may be the k text string vectors with the highest similarity, or any text string vector with a similarity that is greater than a pre-determined value. The identified text string vectors could correspond to a subset of incident reports, within a greater corpus of incident reports that is recorded in the database  702 , that are relevant to an additional incident report that corresponds to the query text string vector. For each of the identified text string vectors, the associated text string may be looked up in database  702  and provided as an output text string. In some cases, the associated incident reports may be provided as well. 
     In some cases, only incident reports that are not older than a pre-determined age are provided. For instance, the system may be configured to identify text string vectors only from incident reports that were resolved within the last 3 months, 6 months, or 12 months. Alternatively, the system may be configured to identify text string vectors only from incident reports that were opened within the last 3 months, 6 months, or 12 months. 
     In this fashion, incident reports with similar problem descriptions as that of the input text string can be rapidly identified. Notably, this system provides contextual results that are more likely to be relevant and meaningful to the input text string. Consequently, an individual can review these incident reports to determine how similar problems as that in the problem description have been reported and addressed in the past. This may result in the amount of time it takes to resolve incidents being dramatically reduced. 
     Additionally or alternatively, these embodiments can be applied to detect and identify clusters of semantically and/or contextually similar incident reports within a corpus of incident reports. For example, clusters of incident reports related to a similar issue that is likely to affect users of an IT system, an ongoing misconfiguration of one or more aspects of an IT system, a progressive hardware failure in a component of an IT system, or some other recurring issue within an IT system. Identifying such clusters of related incident reports can allow the IT system to be repaired or upgraded (e.g., by replacing and/or reconfiguring failing or inconsistently performing hardware or software), users to be trained to avoid common mistakes, rarely-occurring hardware or software issues to be detected and rectified, or other benefits. 
     Such clusters of relevant incident reports can be detected and/or identified by identifying, within the semantically encoded vector space, aggregated word (and/or paragraph) vectors corresponding to the incident reports. A variety of methods could be employed to detect such clusters within the semantically encoded vector space, e.g., k-means clustering, support vector machines, ANNs (e.g., unsupervised ANNs configured and/or trained to identify relevant subsets of training examples within a corpus of available training examples), or some other classifier or other method for identifying clusters of related vectors within a vector space. 
     B. Paragraph Vectors 
     As discussed previously, an ANN model (e.g., 800, 900) uses the surrounding context to provide compact, semantically relevant vector representations of words. After training, words with similar meanings can map to a similar position in the vector space. For example, the vectors for “powerful” and “strong” may appear close to each other, whereas the vectors for “powerful” and “Paris” may be farther apart. Additions and subtractions between word vectors also carry meaning. Using vector algebra on the determined word vectors, we can answer analogy questions such as “King” - “man” + “woman” = “Queen.” 
     However, the complete semantic meaning of a sentence or other passage (e.g., a phrase, several sentences, a paragraph, a text segment within a larger sample of text, or a document) cannot always be captured from the individual word vectors of a sentence (e.g., by applying vector algebra). Word vectors can represent the semantic content of individual words and may be trained using short context windows. Thus, the semantic content of word order and any information outside the short context window is lost when operating based only on word vectors. 
     Take for example the sentence “I want a big green cell right now.” In this case, simple vector algebra of the individual words may fail to provide the correct semantic meaning of the word “cell,” as the word “cell” has multiple possible meanings and thus can be ambiguous. Depending on the context, “cell” could be a biological cell, a prison cell, or a cell of a cellular communications network. Accordingly, the paragraph, sentence, or phrase from which a given word is sampled can provide crucial contextual information. 
     In another example, given the sentence “Where art thou ______,” it is easy to predict the missing word as “Romeo” if sentence was said to derive from a paragraph about Shakespeare. Thus, learning a semantic vector representation of an entire paragraph can help contribute to predicting the context of words sampled from that paragraph. 
     Similar to the methods above for learning word vectors, an ANN or other machine learning structures may be trained using a large number of paragraphs in a corpus to determine the contextual meaning of entire paragraphs, sentences, phrases, or other multi-word text samples as well as to determine the meaning of the individual words that make up the paragraphs in the corpus. Such an ANN  1000  is shown in  FIG.  10 A . ANN  1000  includes input layer  1002 , which feeds into hidden layer  1004 , which in turn feeds into output layer  1006 . Note that input layer  1002  consists of two types of input substructures, the top substructure  1008  (consisting of input nodes Ii... I n ) representing words and the bottom substructure  1010  (consisting of input nodes D 1 ... D m ) representing paragraphs (documents). The number of nodes in output layer  1006  and the top input layer substructure  1008  may be equal to the number of unique words in the entire corpus. The number of nodes in the bottom input layer substructure  1010  may be equivalent to the number of unique paragraphs in the entire corpus. Note that “paragraph,” as used herein, may be a sentence, a paragraph, one or more fields of an incident report, a segment of a larger string of text, or some other multi-word string of text. 
     For each paragraph in the corpus, ANN  1000  is trained with fixed-length contexts generated from moving a sliding window over the paragraph. Thus, a given paragraph vector is shared across all training contexts created from its source paragraph, but not across training contexts created from other paragraphs. Word vectors are shared across training contexts created from all paragraphs, e.g., the vector for “cannot” is the same for all paragraphs. Paragraphs are not limited in size; they can be as large as entire documents or as small as a sentence or phrase. In  FIG.  10 A , ANN  1000  is shown in a single training iteration, being trained with input word context “can’t,” “connect” and “to,” input paragraph context DOC 1, and output word “email.” The output word serves as the ground truth output value to which the result produced by output layer  1006  is compared. This arrangement reflects that “email” appears proximate to “can’t”, “connect”, and “to”, and is within DOC 1. 
     In an implementation, this could be represented as output node O 4  receiving a ground truth value of 1 and all other nodes in output layer  1006  having ground truth values of 0. Similarly, node I 1  has a ground truth value of “can’t,” node I 2  has a ground truth value of “connect,” node I 3  has a ground truth value of “to,” and node Di has ground truth value of DOC 1. In the implementation, this could be represented as nodes I 1 , I 2 , I 3 , and D 1  being associated with values of 1 and all other nodes in input layer  1002  having values of 0. The loss function may be a sum of squared errors, for example, between the output of output layer  1006  and a vector containing the ground truth values. The weight values of the corresponding word vectors and paragraph vectors, as well all the output layer parameters (e.g., softmax weights) are updated based on the loss function (e.g., via backpropagation). 
       FIG.  10 B  shows ANN  1000  being trained with a subsequent context window. This context window derives from the same document, but shifts ahead a word in the document and uses input word context “connect,” “to” and “email,” input paragraph context DOC 1, and output word “server.” In an implementation, these inputs and outputs can be encoded with ground truth values as similarly described above. 
       FIG.  10 C  shows an instance of ANN  1000  trained with another document within the corpus. The context window derives from this document and uses input word context “can’t”, “load”, and “my”, input paragraph context DOC 2, and output word “database.” In an implementation, these inputs and outputs can be encoded with ground truth values as similarly described above. 
     After ANN  1000  is trained, the weights associated with hidden layer  1004  become a compact vector representation of the context and meaning of input words and paragraphs. For example, assuming that ANN  1000  is fully-trained with a corpus of 1,000 paragraphs, with the entire corpus containing 10,000 unique words, each paragraph and each word can be represented by a unique vector with a length equal to the number of hidden nodes in hidden layer  1004 . These unique vectors encode the contextual meaning of words within the paragraphs or the paragraphs themselves. 
       FIG.  10 D  shows ANN  1000  at prediction time performing an inference step to compute the paragraph vector for a new, previously unseen paragraph. This inference step begins by adding an additional input node  1012  to input layer substructure  1010  that represents the unseen paragraph (DOC M+1). During this inference process, the coefficients of the word vectors substructure  1008  and the learned weights between hidden layer  1004  and output layer  1006  are held fixed. Thus, the model generates an additional paragraph vector  1012 , corresponding to the unseen paragraph in the input paragraph vector substructure  1010 , to obtain the new semantic vector representation of the unseen paragraph. Any additional unseen paragraphs can be trained through a similar process by adding input nodes to input layer substructure  1010 . 
     Alternatively, paragraph vectors can be trained by ignoring word context in the input layer, only using the paragraph vector as the input, and forcing the model to predict different word contexts randomly sampled from the paragraph in the output layer. The input layer of such an ANN only consists of paragraph vectors, while the output layer represents a single context window that is randomly generated from a given paragraph. Training such an ANN may result in a vector representation for the semantic content of paragraphs in the corpus, but will not necessarily provide any semantic vector representations for the words therein. 
     Once vector representations have been determined for paragraphs in the corpus, linear and/or multiplicative aggregation of these vectors may be used to represent topics of interest. Furthermore, if the dimensions of paragraph vectors are the same as the dimensions of word vectors, as shown in ANN  1000 , then linear and multiplicative aggregation between word vectors and paragraphs vectors can be obtained. For example, finding the Chinese equivalent of “Julius Caesar” using an encyclopedia as a corpus can be achieved by vector operations PV(“Julius Caesar”) - WV(“Roman”) + WV(“Chinese”), where PV is a paragraph vector (representing an entire Wikipedia article) and WV are word vectors. Thus, paragraph vectors can achieve the same kind of analogies to word vectors with more context-based results. 
     In practice, such learned paragraph vectors can be used as inputs into other supervised learning models, such as sentiment prediction models. In such models, which can include but are not limited to ANNs, Support Vector Machines (SVMs), or Naive Bayes Classifiers, paragraph vectors are used as input with a corresponding sentiment label as output. Other metrics such as cosine similarity and nearest neighbors clustering algorithms can be applied to paragraph vectors to find or group paragraphs on similar topics within the corpus of paragraphs. 
     In the present embodiments, a combination of learned word vectors and paragraph vectors can help determine the structure and meaning of incidents reports, for example incident report  600  as shown in  FIG.  6   . Incident report  600  consists of a number of fields in the left column, at least some of which are associated with values in the right column. For longer text fields, such as short description field  605 , problem description field  606 , resolution field  614 , and notes field  620 , it may be preferable to represent the associated right column text as a paragraph vector, or as multiple paragraph vectors corresponding to respective text segments within the right column text, to gain more contextual meaning rather than aggregating the individual word vectors that form the text. Incident report  600  is presented for purpose of example. Various fields of an incident report can be arranged to be represented as paragraph vectors, word vectors, or weighted combinations of the two. Other types of incident reports, problem reports, case files, or knowledgebase articles may also be used, and these reports may contain more, fewer, and/or different fields. 
     After representing different fields as paragraph vectors, word vectors, or weighted combinations of the two, a single vector to represent the entire incident can be generated by concatenating, generating a vector sum, or otherwise aggregating the word and/or paragraph vector representations of the individual incident fields. With a single aggregate incident vector representation, a system can be configured to identify similar aggregate vectors (and therefore similar incident reports) based on cosine similarity or other metrics as discussed above. Alternatively, a search for similar incident reports may use just the paragraph text of one or more individual fields. In this fashion, text from one or more individual fields in an incident report could be combined into a single paragraph of text. A paragraph vector could then be generated from this single, large paragraph of concatenated text and used to search for similar incidents. 
     This process can be illustrated in terms of the previously described ANN structures. Initially, text strings are obtained from database  702  of  FIG.  7   . As noted above, these text strings may be from parts of incident reports. Then, words are extracted from the text strings. The words extracted may be all of the words in the text strings or some of these words. These extracted words are provided as input to ANN  900  of  FIGS.  9 A- 9 B . The substring contexts of these words are extracted from the text strings. The substring contexts may be one or more substrings containing words before, after, or surrounding the associated words that were extracted. These vector representations may then be used to compare (e.g., using cosine similarity) their respective text samples. 
     The comparison may identify one or more incident reports from database  702  that “match” in this fashion. In some cases this may be the k incident reports with the highest similarity, or any incident report with a similarity that is greater than a pre-determined value. The user may be provided with these identified incident reports or references thereto. 
     In some cases, only incident reports that are not older than a pre-determined age are provided. For instance, the system may be configured to only identify incident reports that were resolved within the last 3 months, 6 months, or 12 months. Alternatively, the system may be configured to only identify incident reports that were opened within the last 3 months, 6 months, or 12 months. 
     In this fashion, incident reports with similar content as that of the input incident report can be rapidly identified. Consequently, an individual can review these incident reports to determine how similar problems as that in the incident have been reported and addressed in the past. This may result in the amount of time it takes to resolve incidents being dramatically reduced. 
     While this section describes some possible embodiments of word vectors and paragraph vectors, other embodiments may exist. For example, different ANN structures and different training procedures can be used. 
     VII. Clustering of Text Queries or Other Records 
     Queries, incident reports, knowledgebase articles, and/or other textual or non-textual records can be clustered together. Such clustering may be performed to provide a variety of benefits. For example, clustering may be applied to a set of records in order to identify patterns or groups within the set of records that have relevance to the operation of a system or organization. Such groups may facilitate the tracking of ongoing problems (e.g., network outages, user confusion interfacing with a network-based service) by measuring a time-dependence of records assigned to a particular cluster associated with the ongoing problem(s). Such groups may facilitate the early identification of newly-emerging problems by, e.g., identifying similarities between newly-received reports. In some examples, clustering may allow similar reports (e.g., reports corresponding to the same cluster(s)) to be manipulated in common, in order to reduce the time required to respond to sets of similar reports. For example, reports that are related to a network outage and that are assigned to a single cluster could all be resolved in a single operation following resolution of the network outage. 
     In some examples, clustering may facilitate the allocation of reports to technicians according to specialty, familiarity, or other factors. Additionally or alternatively, a knowledgebase article, solution flowchart, or other material could be created for each identified cluster in order to facilitate resolution of reports as they are assigned to the clusters. Identifying clusters within a set of queries, incident reports, or other textual or non-textual records can provide additional or alternative benefits. 
     Incident reports, queries, knowledgebase articles, or types of records that may include textual elements and/or non-textual elements can be grouped into clusters in a variety of ways. Such clustering may be performed in a supervised manner in order to generate a clustering algorithm that assigns novel records into clusters according to a manually-classified set of training records. Additionally or alternatively, clustering may be performed in an unsupervised manner in order to generate clusters without the requirement of manually-labeled records, to identify previously un-identified clusters within the training data, or to provide some other benefit. 
     A variety of methods and/or machine learning algorithms could be applied to identify clusters within a set of records and/or to assign records (e.g., newly received or generated records) to already-identified clusters. For example, decision trees, artificial neural networks, k-means, support vector machines, independent component analysis, principal component analysis, or some other method could be trained based on a set of available records in order to generate an ML model to classify the available records and/or to classify records not present in the training set of available records. The inputs to such an ML model could include a variety of features of the records. Such features could be present in the records (e.g., dates and times, status flags, user IDs) and/or determined from information already present in the records (e.g., word vectors, paragraph vectors). The input features could include dates and times or other numerical information related to the records. The input features could include categorical information like user ID numbers or status flags (e.g., ‘open,’ ‘closed-resolved,’ ‘closed-unresolved’). The input features could include information related to textual information (e.g., a ‘problem description’ field) of the records. For example, the input features could be related to word and/or paragraph vectors generated from textual fields of the records and/or other features generated using natural language processing. The input features could be subjected to a mapping (e.g., a nonlinear transformation, a dimensionality reduction) prior to being applied to the ML model. 
       FIG.  11 A  illustrates an example set of records  1100 . For the purposes of illustrating clustering of the records, each record is represented by a respective location within a two-dimensional space. The location of a given record within the space could be related to the value of two features of the given record (e.g., a time of generation of the record and a time of resolution of the record, two dimensions of a paragraph vector generated from text of the record). Alternatively, the location of a given record could be related to a projection of more than two features of the record into the two-dimensional space using a linear or nonlinear dimensionality reduction technique or some other mapping method. 
     Similarity values can be determined for pairs of records in the set of records  1100 . Such similarity values could be used to generate an ML model to cluster the records  1100  such that that records that are ‘similar’ in some sense are assigned to the same cluster, while records that are very ‘dissimilar’ are assigned to different clusters. Such a similarity value could correspond to a distance measure between the records in some space, e.g., the two-dimensional space of  FIG.  11 A , a semantically-encoded vector space related to word and/or paragraph vectors determined from textual aspects of the records, a vector space that includes dimensions relating to the time of generation of the record or other numerical and/or categorical information of the record, etc. Such a distance could be a Euclidean distance, a Manhattan distance, or some other distance measure according to an application. 
       FIG.  11 B  shows each record in the set of records  1100  assigned to one of three clusters  1110 A,  1120 A,  1130 A identified from the set of records  1100 . The assignment of each record is indicated by the shape used to indicate the record; a filled circle for the first cluster  1110 A, an open circle for the second cluster  1120 A, and a square for the third cluster  1130 A. Note that all of the records have been assigned to a cluster; in practice, an ML model used to assign records to clusters could optionally assign records to a residual set of records or take some other action instead of assigning a record to a cluster. This could be done, e.g., to avoid assigning records to clusters when the similarity between the record and any potential cluster is less than a minimum degree of similarity. 
     As noted above, a variety of methods could be used to generate an ML model that assigns records to two or more clusters and/or that assigns records to a set of residual, un-assigned records. Once the ML model has been determined, the ML model can be applied to assign additional records to the identified clusters represented by the ML model and/or to assign records to a set of residual records. The ML model could include parameter values, neural network hyperparameters, cluster centroid locations in feature space, cluster boundary locations in feature space, threshold similarity values, or other information used, by the ML model, to determine which cluster to assign a record and/or to determine that the record should not be assigned to a cluster (e.g., should be stored in a set of residual, un-assigned records). Such information could define a region, within a feature space, that corresponds to each cluster. That is, the information in the ML model could be such that the ML model assigns a record to a particular cluster if the features of the record correspond to a location, within the feature space, that is inside the defined region for the particular cluster. The defined regions could be closed (being fully enclosed by a boundary) or open (having one or more boundaries but extending infinitely outward in one or more directions in the feature space). 
       FIG.  11 C  illustrates such regions  1110 B,  1120 B,  1130 B in the example two-dimensional feature space of  FIG.  11 A . Records of the set of records  1100  fall within the regions  1110 B,  1120 B,  1130 B and thus would be assigned, by an ML model, to clusters that correspond to the regions  1110 B,  1120 B,  1130 B. Records having locations outside of the regions  1110 B,  1120 B,  1130 B could be assigned to a set of residual records. The ML model could include information indicative of the location, shape, extent, or other information about splines, hyperplanes, cells, hyperspheres, or other shapes expressly defining the boundaries and/or extent of the regions  1110 B,  1120 B,  1130 B, within a feature space, that correspond to the clusters represented by the ML model. Additionally or alternatively, the ML model could include network weight parameters, output unit scaling parameters, or other information about a neural network structure or other algorithm that indirectly define the boundaries and/or extent of the regions  1110 B,  1120 B,  1130 B. 
     In some examples, the ML model could include centroids or other location information indicative of the location, within a feature space, of the clusters. A centroid could be a location of an arithmetic or geometric mean of the locations of records in the cluster, a determined geometric center or other defining location of a hypersphere, hyperellipsoid, or other shape fitted to the records of the cluster, or some other location related to the overall location and/or extent of the cluster in a feature space. In such examples, a record could be assigned to a particular cluster when the location of the record, in the feature space, is closer to the centroid of the particular cluster than it is to the centroid of any other cluster. An ML model organized in such a manner could include a k-means classifier. As an illustrative example,  FIG.  11 D  includes three centroids  1115 C,  1125 C,  1135 C in a feature space. Each centroid corresponds to a respective cluster. Records from the set of records  1100  can be assigned to the clusters based on which of the centroids  1115 C,  1125 C,  1135 C is nearest to the location of the record in the feature space. Under such an arrangement, records will be assigned to clusters based on which of the open regions  1110 C,  1120 C,  1130 C the location of the record is within. 
     In some examples, a record could be precluded from assignment to a particular cluster unless a degree of similarity between the cluster and the record is greater than a threshold similarity. This could include a distance between the location of the record and a centroid or other characteristic location of the cluster being less than a threshold distance. Records that are precluded from inclusion in any cluster could be added to a set of residual records. As an illustrative example,  FIG.  11 E  includes three centroids  1115 D,  1125 D,  1135 D in a feature space. Each centroid corresponds to a respective cluster. Records from the set of records  1100  can be assigned to the clusters based on which of the centroids  1115 D,  1125 D,  1135 D is nearest to the location of the record in the feature space and less than a threshold distance d away from the location of the record. Under such an arrangement, records will be assigned to clusters based on which of the closed regions  1110 D,  1120 D,  1130 D the location of the record is within. Note that the threshold distances could vary between the clusters. For example, the threshold distance could be based on a variance of the records assigned to each cluster during training of the ML model. 
     In some examples, the ML model could operate in a specified order to determine whether a record should be assigned to each cluster. For example, the ML model could first determine whether a record should be assigned to a first cluster (e.g., by comparing a distance between a centroid of the first cluster and a location of the record to a threshold distance). If it is determined that the record should not be assigned to the first record, the ML model could operate to determine whether the record should be assigned to a second cluster, and so on. Such a method could have the benefit of reducing the expected computational cost of assigning a record to a cluster (or determining that the record should not be assigned to any cluster). Additionally or alternatively, such a method could allow additional clusters to be added to the model without re-assigning any regions of the feature space to the new cluster that had formerly been associated with any of the pre-existing clusters. This could be done by placing the newly added cluster(s) to the end of the sequence for determining whether the record should be assigned to any of the clusters. 
     As an illustrative example,  FIG.  11 F  includes three centroids  1115 E,  1125 E,  1135 E in a feature space. Each centroid corresponds to a respective cluster. Records from the set of records  1100  can be assigned to the clusters by determining, according to a specified sequence of the clusters, whether the location of the record in the feature space is less than a threshold distance away from the location of the centroid of the cluster(s). Under such an arrangement, records will be assigned to clusters based on which of the closed regions  1110 E,  1120 E,  1130 E the location of the record is within. Note that the threshold distances vary between the clusters. 
     The clustering and ML model training operations described above could be distributed amongst elements of a remote network management platform as described elsewhere herein. For example, an end-user computational instance within the remote network management platform could be dedicated to the management of a particular user and configured to serve web pages, manage the generation and storage of incident reports, maintain and serve a set of knowledgebase articles, manage servers of a managed network, or to perform some other operations related to the maintenance and operation of a managed network of the user. 
     Additional sets of computational resources could be allocated to generate and/or apply ML models based on incident reports, knowledgebase articles, or other textual records related to the end-user computational instance and/or to the managed network. This distribution of tasks can allow ML-related tasks, which can be memory and compute time intensive, to be performed separately from other network management tasks (e.g., serving web pages, managing servers, generating incident reports) so that the performance of those other network management tasks is not degraded when generating or applying an ML model. Additionally, this distribution of tasks could allow resources used to generate and apply ML models to be shared between different users of the remote network management platform to increase efficiency. 
     In some examples, a training computational instance could generate the ML model initially. This could be done in response to a request for such from the end-user computational instance. The training instance can then access a set of incident reports or other records related to the end-user computational instance (e.g., by receiving such information from the end-user computational instance) and use that information to generate the ML model. The generated ML model could then be stored by the training instance for later use, transmitted to the end-user instance for storage/later use, and/or stored in some other location for later use. 
     Additional incident reports or other records could then be assigned into clusters and/or added to a set of residual records using the trained ML model. This could be done by the end-user instance. Alternatively, a prediction computational instance within the remote network management platform could receive a request for such classification from the end-user instance. Such a request could include an indication of the incident report or record to be classified. The prediction instance could then apply the ML model to assign the incident report or other record to a cluster or to the set of residual records. The prediction instance could access the ML model from a local memory or from a database that is not part of the prediction instance. For example, the prediction instance could determine that the relevant ML model is not present in a memory (e.g., hard drive, database) of the prediction instance and, responsive to that determination, the prediction instance could transmit, to the end-use instance, a request for a copy of the ML model. Once the prediction instance has assigned the incident report or other record to a particular cluster, the prediction instance can transmit, to the end-user instance, a representation of the particular cluster. 
     Transmitting a representation of one or more clusters of textual records within a corpus of textual records can include transmitting a variety of information related to the represented cluster(s). This can include transmitting an identification number (e.g., a GUID), a location within a database, or some other identifying information that can enable the end-user instance to identify the represented cluster of textual records. Additionally or alternatively, a representation of the contents of the cluster of textual records could be transmitted. This could include transmitting identification information for the textual records within the cluster (e.g., GUIDs, locations within a database), all or part of the contents of the textual records within the cluster (e.g., text from ‘problem resolution’ fields of incident reports within the cluster), the contents of one or more representative textual records associated with the cluster (e.g., a knowledgebase article associated with the cluster, a ‘problem resolution’ field or other contents of an incident report that is near a centroid of the cluster), or some other content associated with the cluster. 
     Transmitting a representation of one or more textual records in a corpus of textual records can include transmitting a variety of different information. In some examples, transmitting a representation of a textual record includes transmitting an identification number (e.g., a global unique identifier (GUID)), time and date stamp, a location within a database, or some other identifying information that can enable the end-user instance to identify the represented textual record in a database or to otherwise access the represented textual record. Additionally or alternatively, transmitting a representation of a textual record can include transmitting a copy of the textual record itself or a portion thereof. For example, transmitting a representation of a textual record can include transmitting a copy of a ‘problem resolution’ field of an incident report. 
     VIII. Clustering of Text Queries or Other Records 
     Generating an ML model to identify related clusters of incident reports (or other records) within a training set of incident reports, and using that ML model to subsequently assign newly-generated incident reports to the identified clusters, can provide a variety of benefits. However, the process of initially generating the ML model can be computationally expensive. Accordingly, the ML model may be used for an extended period of time following its initial generation. However, as new incident reports are generated over time, the effectiveness of the ML model may be reduced. This could be related to the presence of novel clusters of related incident reports within the newly-generated incident reports, changes in the properties over time of the identified clusters (e.g., movement through a feature space), or other processes. Accordingly, the ML model may be re-generated, based in whole or in part on the newly-generated incident reports, according to a specified schedule or some other criteria. 
     The accuracy of the ML model between these updates may be further increased by performing partial updates based on residual incident reports that have not been assigned to the clusters already identified in the ML model. Such residual incident reports could have been added to the set of residual records due to being less similar to all of the identified clusters than a threshold similarity. For example, the residual incident reports could all be more than a maximum distance, in a feature space, from the centroid or other location of any of the identified clusters. Accordingly, these residual records may represent un-identified clusters in the data and can be periodically analyzed, between full re-generations of the ML model, to determine whether additional clusters should be added to the ML model. This solution has the benefit of being less computationally expensive than a full re-generation of the ML model while allowing the ML model to detect emerging clusters in the newly-generated incident reports. 
       FIG.  12 A  illustrates an example set of records  1200 . For the purposes of illustrating clustering of the records, each record is represented by a respective location within a two-dimensional space. Similarity values can be determined for pairs of records in the set of records  1200  and used to generate an ML model to cluster the records  1200  such that that records that are ‘similar’ in some sense are assigned to the same cluster, while records that are very ‘dissimilar’ are assigned to different clusters. 
       FIG.  12 B  shows each record in the set of records  1200  and a set of three clusters  1210 ,  1220 ,  1230  identified from the set of records  1200 . A subset of the records (indicated by the filled circles) have been assigned into the clusters  1210 ,  1220 ,  1230 . A disjoint subset of the records  1200  have been added to a set of residual incident reports (indicated by the open circles) due, e.g., to those records being less similar to any of the identified clusters  1210 ,  1220 ,  1230  than a threshold degree of similarity. As shown in  FIG.  12 B , such a threshold degree of similarity could correspond to a maximum distance in a feature space, and the threshold level of similarity may vary amongst the clusters. 
     Over time, additional incident reports can be generated.  FIG.  12 C  shows the original set of incident reports  1200  (indicated by closed or filled circles), the identified clusters  1210 ,  1220 ,  1230 , and a set of newly-generated incident reports (closed or filled squares). The ML model has been applied to these additional incident reports to assign some of the additional incident reports (filled squares) to corresponding clusters. Additional incident reports that have been determined not to correspond to any of the identified clusters  1210 ,  1220 ,  1230  have been added to the set of residual incident reports (open squares). 
     Prior to completely re-generating the ML model, the set of residual incident reports can be analyzed in order to identify additional clusters that are not already present in the ML model. This analysis may occur according to a set schedule (e.g., every 15 minutes). Additionally or alternatively, the analysis to identify additional clusters from the set of residual incident reports may occur in response to some other criteria. For example, the analysis may occur in response to a specified number of additional incident reports being added to the set of residual incident reports. 
       FIG.  12 D  shows an additional cluster  1240  that has been identified from the set of residual records (open circles/squares) shown in  FIG.  12 C . Incident reports from the set of residual incident reports that correspond to the newly identified cluster  1240  have been removed from the set of residual incident reports and assigned to the newly identified cluster  1240 . Note that the incident reports assigned to the newly identified cluster  1240  can include both incident reports that were part of the original training set of incident reports as well as incident reports generated subsequently. 
     The algorithm used to identify the additional cluster(s) from the set of residual incident reports could be the same algorithm used to originally generate the ML model. Alternatively, a different method could be applied. The ML model may be expanded to include the newly identified cluster(s). This expanded ML model could be transmitted to the corresponding end-user computational instance (e.g., for distribution to other prediction and/or training instances, for the purpose of protecting the end-user’s data) or to some other database for later use by a prediction instance or by some other system or component. 
     The above-described process can act to iteratively add clusters to an ML model based on a residual set of incident reports. As new clusters are identified, incident reports that belong to the new clusters are removed from the set of residual incident reports. Accordingly, the order in which incident reports are applied to the ML model, and thus potentially added to the set of residual incident reports, can have an effect on the clusters that are identified via this method. In order to ensure that the same set of clusters is identified by multiple different prediction instances (or other instances performing these operations), the ordering of the incident reports can be recorded and made available to the prediction instances. 
     For example, a prediction instance could determine that it has an out-of-date version of the ML model. The version of the ML model could be out of date due to not representing all of the relevant incident reports that had been generated. In response to determining that it’s local version of the ML model is out-of-date, the prediction instance could request, from an end-user instance, information about newly generated incident reports as well as the order in which those incident reports were received. The prediction instance could then apply the newly generated incident reports in order to update the out-of-date version of the ML model. Under such an update scheme, multiple different prediction instances could independently generate identical updated ML models. 
     The above methods can be applied to update an ML model based on incident reports that were not used to initially generate the ML model. Periodically, an ML model updated via these methods may be completely re-generated. This may be done according to a specified schedule or in response to some other criteria (a ‘refresh criterion’) in order to provide more accurate, up-to-date clusters or to provide some other benefit. In some instances, it may be beneficial to preserve, in some manner, one or more of the identified clusters from the previous ML model. This could be done to preserve clusters that have become useful, that have been the focus of significant development work (e.g., to create knowledgebase articles, resolution workflows, or other efforts), that are related to an ongoing concern or event (e.g., a network or service outage), or that are desirable in some other manner. In such examples, a user could specify the one or more clusters to be preserved, and some information related to the specified clusters could be used to re-generate the ML model. 
     Generating an ML model to preserve one or more specified clusters from a previous model could include a variety of processes. In some examples, a corresponding cluster of the new ML model could be set according to a specified cluster. This could include defining the corresponding cluster in the new ML to have the same centroid, maximum distance threshold, or other properties according to the corresponding properties of the specified cluster from the previous ML model. Additionally or alternatively, an initial state or seed of one or more clusters in the new ML model could be set to such information of the specified cluster, such that the corresponding cluster of the new ML model may differ slightly from the specified cluster (e.g., to account for changes in the properties of the underlying process related to the specified cluster). 
     In some examples, the new ML model could be generated such that some or all of the members of the specified cluster remain in the same cluster. This could include using a supervised model generation algorithm with the members of the specified cluster tagged as having the same ‘true’ output classification. The ML model generation algorithm could then operate based on these tags, as well as other information. This could be a hard requirement, requiring all of the members of the specified cluster to be assigned to a single cluster in common by the new ML model. Alternatively, this could be a soft requirement, allowing some of the members of the specified cluster to be separated amongst multiple different clusters in the new ML model. 
     IX. Example Operations 
       FIG.  13    is a flow chart illustrating an example embodiment. The process illustrated by  FIG.  13    may be carried out by a computing device, such as computing device  100 , and/or a cluster of computing devices, such as server cluster  200 . However, the process can be carried out by other types of devices or device subsystems. For example, the process could be carried out by a portable computer, such as a laptop or a tablet device. 
     The embodiments of  FIG.  13    may be simplified by the removal of any one or more of the features shown therein. Further, these embodiments may be combined with features, aspects, and/or implementations of any of the previous figures or otherwise described herein. 
     The example method of  FIG.  13    includes receiving, by a prediction computational instance and from an end-user computational instance, a first textual record ( 1300 ). The end-user computational instance is dedicated to a managed network, and the prediction computational instance and the end-user computational instance are both disposed within a remote network management platform. 
     The example method of  FIG.  13    additionally includes applying an ML pipeline to the target data set ( 1300 ). The example method of  FIG.  13    further includes determining, by an ML clustering model of the prediction computational instance that represents a set of clusters of textual records, that the first textual record corresponds to a particular cluster selected from the set of clusters of textual records ( 1302 ). The example method of  FIG.  13    yet further includes transmitting, by the prediction computational instance and to the end-user computational instance, a representation of the particular cluster ( 1304 ). 
     The example method of  FIG.  13    additionally includes receiving, by the prediction computational instance and from the end-user computational instance, a second textual record ( 1306 ). The example method of  FIG.  13    also includes determining, by the ML clustering model, that the second textual record does not correspond to any cluster of textual records of the set of clusters of textual records ( 1308 ). The example method of  FIG.  13    additionally includes adding, by the prediction computational instance, the second textual record to a stored set of residual textual records in response to determining that the second textual record does not correspond to any cluster of textual records of the set of clusters of textual records ( 1310 ). 
     The example method of  FIG.  13    yet further includes identifying, by the prediction computational instance, an additional cluster of textual records based on the stored set of residual textual records ( 1312 ). The example method of  FIG.  13    also includes transmitting, by the prediction computational instance and to the end-user computational instance, a representation of the additional cluster of textual records ( 1314 ). 
     The example method of  FIG.  13    could include additional or alternative steps. In some examples, the prediction computational instance is a first prediction computational instance and the ML clustering model is a first ML clustering model and the example method of  FIG.  13    could additionally include: (i) receiving, by the first prediction computational instance and from the end-user computational instance prior to receiving the first textual record, a first plurality of textual records; (ii) prior to receiving the first textual record, using, by the first prediction computational instance, a non-stochastic iterative algorithm to determine the first ML clustering model based on the first plurality of textual records; (iii) receiving, by a second prediction computational instance and from the end-user computational instance, a second textual record; (iv) determining, by the second prediction computational instance, that the second prediction computational instance does not contain an up-to-date ML clustering model corresponding to the end-user computational instance; (v) responsive to determining that the second prediction computational instance does not contain an up-to-date ML clustering model corresponding to the end-user computational instance, receiving, by the second prediction computational instance and from the end-user computational instance, the first plurality of textual records, an indication of an ordering of textual records within the first plurality of textual records, and the first textual record; (vi) using, by the second prediction computational instance, the non-stochastic iterative algorithm to determine, based on the first plurality of textual records and the first textual record, a second ML clustering model that represents a set of clusters of textual records, wherein using the non-stochastic iterative algorithm to determine the second ML clustering model includes using each textual record in the first plurality of textual records and the first textual record, in order, to update the second ML clustering model via the non-stochastic iterative algorithm; (vii) determining, by the second ML clustering model, that the second textual record corresponds to a particular cluster selected from the set of clusters of textual records; and (viii) transmitting, by the second prediction computational instance and to the end-user computational instance, a representation of the particular cluster. Using the non-stochastic iterative algorithm to determine the first ML clustering model includes using each textual record in the first plurality of textual records, in order, to update the first ML clustering model via the non-stochastic iterative algorithm. 
     In some examples, determining, by the ML clustering model, that the first textual record corresponds to the particular cluster selected from the set of clusters of textual records includes at least one of: (i) using the ML model to determine word vectors that describe, in a first semantically-encoded vector space, a meaning of respective words of the first textual record and comparing the word vectors to at least one of a location or a volume, within the first semantically-encoded vector space, that corresponds to the particular cluster; or (ii) using the ML model to determine a paragraph vector that describes, in a second semantically-encoded vector space, a meaning of multiple words of the first textual record and comparing the paragraph vector to at least one of a location or a volume, within the second semantically-encoded vector space. 
     In some examples, the ML clustering model includes a respective location, within a vector space, of each set of clusters of textual records represented by the ML clustering model. In such examples, determining, by the ML clustering model, that the first textual record corresponds to the particular cluster selected from the set of clusters of textual records can include: (i) determining, based on the first textual record, a first textual record location within the vector space, and (ii) determining that a distance, within the vector space, between the first textual record location and a location of the particular cluster is less than a threshold distance 
       FIG.  14    is a flow chart illustrating an example embodiment. The process illustrated by  FIG.  14    may be carried out by a computing device, such as computing device  100 , and/or a cluster of computing devices, such as server cluster  200 . However, the process can be carried out by other types of devices or device subsystems. For example, the process could be carried out by a portable computer, such as a laptop or a tablet device. 
     The embodiments of  FIG.  14    may be simplified by the removal of any one or more of the features shown therein. Further, these embodiments may be combined with features, aspects, and/or implementations of any of the previous figures or otherwise described herein. 
     The example method of  FIG.  14    includes obtaining a plurality of textual records divided into clusters and a residual set of the textual records, wherein an ML clustering model divided the plurality of textual records based on a similarity metric ( 1400 ). The example method of  FIG.  14    additionally includes receiving, from a client device, a particular textual record representing a query ( 1402 ). The example method of  FIG.  14    also includes determining, by way of the ML clustering model and based on the similarity metric, that the particular textual record does not fit into any of the clusters ( 1404 ). The example method of  FIG.  14    yet further includes adding the particular textual record to the residual set of the textual records in response to determining that the particular textual record does not fit into any of the clusters ( 1406 ). The example method of  FIG.  14    could include additional or alternative steps. In some examples, the example method of  FIG.  14    could additionally include: (i) receiving, from the client device, a second particular textual record representing a second query; (ii) determining, by way of the ML clustering model and based on the similarity metric, that the second particular textual record fits into a particular cluster of the clusters; and (iii) in response to determining that the second particular textual record fits into the particular cluster of the clusters, adding the second particular textual record to the particular cluster. In such examples, determining that the particular textual record fits into the particular cluster can include determining that the similarity metric indicates that the particular textual record fits into the particular cluster better than the particular textual record fits into all other clusters. Additionally or alternatively, determining that the particular textual record fits into the particular cluster can include determining that the similarity metric indicates that the particular textual record fits into the particular cluster to a degree that exceeds a specified threshold similarity. Additionally or alternatively, the ML clustering model can include a respective location, within a vector space, of each of the clusters of the textual records and determining that the second particular textual record fits into the particular cluster can include: (i) determining, based on the second particular textual record, a second textual record location within the vector space, and (ii) determining that a distance, within the vector space, between the second textual record location and a location of the particular cluster is less than a threshold distance. 
     In some examples, the example method of  FIG.  14    could additionally include: (i) identifying, by way of the ML clustering model, that the residual set of the textual records contains a further cluster; (ii) adding the further cluster to the clusters of the textual records; and (iii) removing constituent textual records of the further cluster from the residual set of the textual records. In some examples, determining that the particular textual record does not fit into any of the clusters can include at least one of: (i) using the ML clustering model to determine word vectors that describe, in a first semantically-encoded vector space, a meaning of respective words of the particular textual record and comparing the word vectors to at least one of locations or volumes, within the first semantically-encoded vector space, that respectively correspond to the clusters; or (ii) using the ML model to determine a paragraph vector that describes, in a second semantically-encoded vector space, a meaning of multiple words of the particular textual record and comparing the paragraph vector to at least one of locations or volumes, within the second semantically-encoded vector space, that respectively correspond to the clusters. 
     X. Conclusion 
     The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those described herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. 
     The above detailed description describes various features and operations of the disclosed systems, devices, and methods with reference to the accompanying figures. The example embodiments described herein and in the figures are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations. 
     With respect to any or all of the message flow diagrams, scenarios, and flow charts in the figures and as discussed herein, each step, block, and/or communication can represent a processing of information and/or a transmission of information in accordance with example embodiments. Alternative embodiments are included within the scope of these example embodiments. In these alternative embodiments, for example, operations described as steps, blocks, transmissions, communications, requests, responses, and/or messages can be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved. Further, more or fewer blocks and/or operations can be used with any of the message flow diagrams, scenarios, and flow charts discussed herein, and these message flow diagrams, scenarios, and flow charts can be combined with one another, in part or in whole. 
     A step or block that represents a processing of information can correspond to circuitry that can be configured to perform the specific logical functions of a herein-described method or technique. Alternatively or additionally, a step or block that represents a processing of information can correspond to a module, a segment, or a portion of program code (including related data). The program code can include one or more instructions executable by a processor for implementing specific logical operations or actions in the method or technique. The program code and/or related data can be stored on any type of computer readable medium such as a storage device including RAM, a disk drive, a solid state drive, or another storage medium. 
     The computer readable medium can also include non-transitory computer readable media such as computer readable media that store data for short periods of time like register memory and processor cache. The computer readable media can further include non-transitory computer readable media that store program code and/or data for longer periods of time. Thus, the computer readable media may include secondary or persistent long term storage, like ROM, optical or magnetic disks, solid state drives, compact-disc read only memory (CD-ROM), for example. The computer readable media can also be any other volatile or non-volatile storage systems. A computer readable medium can be considered a computer readable storage medium, for example, or a tangible storage device. 
     Moreover, a step or block that represents one or more information transmissions can correspond to information transmissions between software and/or hardware modules in the same physical device. However, other information transmissions can be between software modules and/or hardware modules in different physical devices. 
     The particular arrangements shown in the figures should not be viewed as limiting. It should be understood that other embodiments can include more or less of each element shown in a given figure. Further, some of the illustrated elements can be combined or omitted. Yet further, an example embodiment can include elements that are not illustrated in the figures. 
     While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purpose of illustration and are not intended to be limiting, with the true scope being indicated by the following claims.