Patent Publication Number: US-11658972-B2

Title: Isolated cell architecture for cloud computing platform

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related to application Ser. No. 17/036,345, filed Sep. 29, 2020, entitled “TECHNIQUES FOR EFFICIENT COMPUTE RESOURCE HARVESTING,” the entire contents of which is hereby incorporated by reference as if fully set forth herein, under 35 U.S.C. § 120. 
     BACKGROUND 
     Cloud-based platforms have become increasingly common for end-to-end data management in database systems, such as Extract-Transform-Load (ETL) database systems. Such cloud-based platforms may offer entire suites of cloud solutions built around a customer&#39;s data. However, customers can be negatively impacted by computing device failures, service unavailability, and even other customers&#39; usage of the cloud platform. 
     Embodiments described herein address these and other problems, individually and collectively. 
     BRIEF SUMMARY 
     Techniques are provided (e.g., a method, a system, non-transitory computer-readable medium storing code or instructions executable by one or more processors) for enabling provisioning of cloud services for a client in an isolated yet scalable manner. Various embodiments are described herein, including methods, systems, non-transitory computer-readable storage media storing programs, code, or instructions executable by one or more processors, and the like. 
     One embodiment is directed to a method performed by a service application that includes generating a cell associated with a service, the cell comprising at least a container engine, implementing, within the container engine, a number of resources associated with the service, instantiating the cell on a number of computing devices, receiving, from a client, a request for access to the service, and assigning the client to an instance of the cell on one of the number of computing devices. 
     Another embodiment is directed to a computing device comprising a processor; and a memory including instructions that, when executed with the processor, cause the computing device to generate a cell associated with a service, the cell comprising at least a container engine, implement, within the container engine, a number of resources associated with the service, instantiate the cell on a number of second computing devices, receive, from a client, a request for access to the service, and assign the client to an instance of the cell on one of the number of second computing devices. 
     Yet another embodiment is directed to a non-transitory computer readable medium storing specific computer-executable instructions that, when executed by a processor, cause a computer system to at least: generate a cell associated with a service, the cell comprising at least a container engine, implement, within the container engine, a number of resources associated with the service, instantiate the cell on a number of second computing devices, receive, from a client, a request for access to the service, and assign the client to an instance of the cell on one of the number of second computing devices. 
     The foregoing, together with other features and embodiments will become more apparent upon referring to the following specification, claims, and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    depicts an illustrative system in which embodiments may be implemented in accordance with various embodiments; 
         FIG.  2    depicts an illustrative example of a cell architecture that may be implemented in accordance with at least some embodiments; 
         FIG.  3    depicts an example implementation in which multiple cells are instantiated across a number of computing devices in accordance with at least some embodiments; 
         FIG.  4    depicts a process for generating cells and assigning client requests to a cell in accordance with at least some embodiments; 
         FIG.  5    depicts a flow diagram illustrating an example process for performing a migration of data via a transaction in accordance with embodiments; 
         FIG.  6    is a block diagram illustrating one pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  7    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  8    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  9    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  10    is a block diagram illustrating an example computer system, according to at least one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, for the purposes of explanation, specific details are set forth in order to provide a thorough understanding of certain embodiments. However, it will be apparent that various embodiments may be practiced without these specific details. The figures and description are not intended to be restrictive. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. 
     The present disclosure relates to a system and techniques for enabling provisioning of cloud services for a client in an isolated yet scalable manner. To do this, various computing resources are implemented within a cell architecture, which is a self-sufficient unit. In some embodiments, a number of cells are generated for a service or a group of services across a number of computing devices. Various cells may be generated that each pertain to an aspect, or particular functionality, of the service. In some embodiments, cells generated to provide various functionality for the service are implemented and distributed across different computing devices. 
     When a client requests access to a service, the client is routed to a cell that is provisioned with computing resources configured to provide the requested service. The client is assigned to a namespace for that client within the cell, such that the client&#39;s resource usage is isolated from other clients using the cell. 
     Embodiments provide for a number of advantages over conventional systems. For example, the embodiments described herein provide for a means of providing scalability when servicing a number of clients while preventing any one client from negatively impacting the other clients. Each cell provides the ability to implement individual computing resource limits on a particular client or clients such that the resource usage of those clients does not impact other clients. Additionally, the cell architecture can be implemented in a manner such that functionality for a particular service is distributed across a number of different computing devices. In this implementation, a client is left with at least partial functionality in the event of a computing device failure. 
       FIG.  1    depicts an illustrative system in which embodiments may be implemented in accordance with various embodiments. As will be appreciated, although a Web-based environment is used for purposes of explanation, different environments may be used, as appropriate, to implement various embodiments.  FIG.  1    depicts an illustrative system  100  that includes at least one electronic client device  102 , which can include any appropriate device operable to send and receive requests, messages or information over an appropriate network  104  and convey information back to a user of the device  102 . Examples of such client devices include personal computers, cell phones, handheld messaging devices, laptop computers, set-top boxes, personal data assistants, electronic book readers and the like. The network can include any appropriate network, including an intranet, the Internet, a cellular network, a local area network or any other such network or combination thereof. Components used for such a system can depend at least in part upon the type of network and/or environment selected. Protocols and components for communicating via such a network may be known to one skilled in the art and will not be discussed herein in detail. Communication over the network can be enabled by wired or wireless connections and combinations thereof. In this example, the network includes the Internet, as the illustrative system includes a Web server  106  for receiving requests and serving content in response thereto, although for other networks an alternative device serving a similar purpose could be used as would be apparent to one of ordinary skill in the art. 
     The illustrative system includes at least one application server  108 . It should be understood that there can be several application servers, layers, or other elements, processes or components, which may be chained or otherwise configured, which can interact to perform tasks such as obtaining data from an appropriate data store. As used herein the term “data store” refers to any device or combination of devices capable of storing, accessing and retrieving data, which may include any combination and number of data servers, databases, data storage devices and data storage media, in any standard, distributed or clustered environment. The application server can include any appropriate hardware and software for integrating with the data store as needed to execute aspects of one or more applications for the client device, handling a majority of the data access and business logic for an application. The application server provides access control services in cooperation with the data store and is able to generate content such as text, graphics, audio and/or video to be transferred to the user, which may be served to the user by the Web server in the form of HyperText Markup Language (“HTML”), Extensible Markup Language (“XML”) or another appropriate structured language in this example. The handling of all requests and responses, as well as the delivery of content between the client device  102  and the application server  108 , can be handled by the Web servers  106 . It should be understood that the Web and application servers are not required and are merely example components, as structured code discussed herein can be executed on any appropriate device or host machine as discussed elsewhere herein. 
     Each server typically will include an operating system that provides executable program instructions for the general administration and operation of that server and typically will include a computer-readable storage medium (e.g., a hard disk, random access memory, read only memory, etc.) storing instructions that, when executed by a processor of the server, allow the server to perform its intended functions. Suitable implementations for the operating system and general functionality of the servers are known or commercially available and are readily implemented by persons having ordinary skill in the art, particularly in light of the disclosure herein. 
     The illustrative system includes an environment in one embodiment that is a distributed computing environment utilizing several computer systems and components that are interconnected via communication links, using one or more computer networks or direct connections. However, it will be appreciated by those of ordinary skill in the art that such a system could operate equally well in a system having fewer or a greater number of components than are illustrated in  FIG.  1   . Thus, the depiction of the system  100  in  FIG.  1    should be taken as being illustrative in nature and not limiting to the scope of the disclosure. 
     The application servers  108  may implement a cloud platform  110 . The cloud platform  110  may implement at least a service application  112  and a number of cloud server instances  114  each of which execute a client application  116 . Additionally, the cloud platform  110  may include one or more computing resources  118 . In accordance with some embodiments, one or more additional cloud server instances  114  may be instantiated (or spun up) or shut down as the client&#39;s demand for resources changes. Each cloud service instance  114  which is instantiated executes a client application  116  associated with a client for which the cloud service instance  114  was instantiated. Each client application  116  of a cloud server instance  114  may consume various resources of computing resource  118 . In certain embodiments, techniques as described herein may be implemented within the cloud platform  110  in order to prevent inappropriate use of computing resources  118  by the client applications  116  while preventing loss of functionality and maintaining scalability. 
     The illustrative system  100  may utilize at least one network  104  that would be familiar to those skilled in the art for supporting communications using any of a variety of commercially-available protocols, such as Transmission Control Protocol/Internet Protocol (“TCP/IP”), Open System Interconnection (“OSI”), File Transfer Protocol (“FTP”), Universal Plug and Play (“UpnP”), Network File System (“NFS”), Common Internet File System (“CIFS”) and AppleTalk. The network can be, for example, a local area network, a wide-area network, a virtual private network, the Internet, an intranet, an extranet, a public switched telephone network, an infrared network, a wireless network and any combination thereof. 
     In embodiments utilizing a Web server, the Web server can run any of a variety of server or mid-tier applications, including Hypertext Transfer Protocol (“HTTP”) servers, FTP servers, Common Gateway Interface (“CGI”) servers, data servers, Java servers and business application servers. The server(s) also may be capable of executing programs or scripts in response requests from user devices, such as by executing one or more Web applications that may be implemented as one or more scripts or programs written in any programming language, such as Java®, C, C# or C++, or any scripting language, such as Perl, Python or TCL, as well as combinations thereof. The server(s) may also include database servers, including without limitation those commercially available from Oracle®, Microsoft®, Sybase® and IBM®. 
     The various embodiments further can be implemented in a wide variety of operating environments, which in some cases can include one or more user computers, computing devices or processing devices which can be used to operate any of a number of applications. User or client devices can include any of a number of general purpose personal computers, such as desktop or laptop computers running a standard operating system, as well as cellular, wireless and handheld devices running mobile software and capable of supporting a number of networking and messaging protocols. Such a system also can include a number of workstations running any of a variety of commercially-available operating systems and other known applications for purposes such as development and database management. These devices also can include other electronic devices, such as dummy terminals, thin-clients, gaming systems and other devices capable of communicating via a network. 
     For clarity, a certain number of components are shown in  FIG.  1   . It is understood, however, that embodiments may include more than one of each component. In addition, some embodiments may include fewer than or greater than all of the components shown in  FIG.  1   . In addition, the components in  FIG.  1    may communicate via any suitable communication medium (including the Internet), using any suitable communication protocol. 
       FIG.  2    depicts an illustrative example of a cell architecture that may be implemented in accordance with at least some embodiments. For the purposes of this disclosure, a cell  202  may be any logical grouping used to identify the components of a service stack that can be grouped as a unit of scale and isolation. In some embodiments, a cell may include at least a container engine  204  and a transaction processor  206 . A container engine  204  may be any piece of software that accepts client requests and runs a container from the client&#39;s perspective. A container is a discrete environment set up within an operating system in which one or more applications may be run, typically assigned only those resources necessary for the application to function correctly. A transaction processor  206  may be any software application that conducts transactions within a cloud platform on behalf of a client. 
     In some embodiments, the container engine  204  includes one or more layers. For example, the container engine  204  may include a service layer  208 , a monitoring layer  210 , and a data layer  212 . The service layer  208  may contain a number of service applications that perform various functions within the cloud computing platform. For example, the service layer  208  may include a number of software applications that read, retrieve, manipulate, or otherwise use, data from the data layer  212 . The monitoring layer  210  may include a number of applications that track resource usage in relation the cell. For example, the monitoring layer  210  may track usage of data in the data layer  212  by the service layer  208 . In some embodiments, the monitoring layer  210  may include applications that enable scalability within the cell  202 . The data layer  212  may include data to be consumed by the service layer  208 . In some embodiments, the data layer  212  may include a data sharded from a data source. 
     In some embodiments, each cell may be associated with a particular cloud service via its configuration. For example, a cell associated with a particular cloud service may include implementations of each of the applications associated with that cloud service within its service layer  208 , monitoring layer  210 , and/or data layer  212 , such that each cell is a self-sufficient and fully functional deployment of the service. Accordingly, implementation of the cell architecture is useful as a pattern used for limiting blast radius, for identifying resource affinities, for grouping clients based on access patterns, and for defining performance and capacity pools. 
     In some embodiments, a number of cells  202  (1-N) may be implemented across a number of different computing devices. As clients request access to cloud services, the clients may each be assigned to cells that correspond to the requested cloud services and/or cells that comply with client requirements or limits by a router  214 . In some embodiments, the router  214  may be a load balancing router that distributes processing evenly across the different computing devices. In certain embodiments, multiple types of cells may be associated with a single client or service. For example, a particular service may require both design time availability and runtime availability. In this example, design time use cases may include curation, tagging, classifying, profiling, or dataset discovery through search, that may each require access to a catalog application. Runtime use cases may include query and pipeline workloads that use information in the repository, which may each require access to a metastore application. In these embodiments, separate cells may be implemented for each of the use cases. To do this, a design time cell for the service may be implemented on at least one first computing device and a runtime cell for the service may be implemented on at least one second computing device. Each layer of the cells can include a shard of the appropriate resources. For example, a data layer  212  of the runtime cell may include a shard of the data store relevant to the runtime use cases whereas the data layer  212  of the design time cell may include a shard of the data relevant to the design time use cases. By separating the use cases for the service in this manner, and by ensuring that the second computing device is not the same as the first computing device, the system can ensure at least partial availability of the service during cell/device failure. For example, runtime use cases will remain available even during a cell failure of the design time components. 
       FIG.  3    depicts an example implementation in which multiple cells are instantiated across a number of computing devices in accordance with at least some embodiments. In  FIG.  3   , a service application  302  and a number of computing resources  304  may be implemented within a cloud computing platform. The service application  302  and computing resources  304  may be examples of the respective service application  112  and computing resources  118  described with respect to  FIG.  1    above. 
     In some embodiments, the service application  302  has access to profile data  306 , which indicates a grouping of resources to be included within a cell architecture. In some embodiments, the profile data  306  may also indicate one or more conditions under which a client may be assigned to a particular cell or type of cell. When the service application  302  determines that a particular service is needed (e.g., based on a predicted demand or a request for the service), the service application generates a cell  308  in accordance with profile data  306  and implements the cell  308  on a computing device  310 . 
     To generate a cell  308 , the service application  302  first identifies which of the computing resources  304  (e.g., applications and data) are required to provide the service. The service application  302  then creates a shard that includes the identified resources. For example, the shard may include only applications that are required to perform the service as well as portions of a data store that are relevant to the service. In this example, the portion of the data store may be duplicated within the cell so that the cell  308  is provided the ability to independently perform the service using the portion of the data store. 
     In some embodiments, multiple cells may provide access to the service to be provided. The service application may implement a number of cells (e.g.,  308 ,  312 , and  316 ) which each include resources for providing the service. However, each of the cells  308 ,  312 , and  316  may be configured differently, in that each may provide an emphasis on different aspects of the service. For example, if a service include three primary functions (e.g., function  1 , function  2 , and function  3 ), then cell  308  may be have more resources (e.g., computing power, etc.) dedicated to function  1 , cell  312  may be have more resources dedicated to function  2 , and cell  316  may be have more resources dedicated to function  3 . This enables clients to be assigned to cells based on their expected needs. 
     In some embodiments, multiple cells may provide different aspects of a service. For example, a particular service may require both design time availability and runtime availability. In this example, design time use cases may include curation, tagging, classifying, profiling, or dataset discovery through search, that may each require access to a catalog application. Runtime use cases may include query and pipeline workloads that use information in the repository, which may each require access to a metastore application. In these embodiments, separate cells (e.g.,  308  and  312 ) may be implemented for each of the use cases. To do this, a design time cell  308  for the service may be implemented on at least one first computing device  310  and a runtime cell  312  for the service may be implemented on at least one second computing device  314 . Each of the cells can include a shard of the appropriate resources. In this example, aspects of the service are implemented via different cells (e.g.,  308  and  312 ) and on different computing devices (e.g.,  310  and  314 ). Accordingly, even if one of the computing devices becomes inoperative, a client working with the service will still have access to a portion of the functionality associated with the service. 
       FIG.  4    depicts a process for generating cells and assigning client requests to a cell in accordance with at least some embodiments. A first portion of the process  400  (e.g., steps  1 - 5 ) may be implemented prior to receiving any request from a client and a second portion of the process  400  (e.g., steps  6 - 8 ) may be implemented each time that a client requests a new instance of the services. 
     At step  1  of the process  400 , a service application  402  receives a request to implement a number of services in accordance with embodiments. In some embodiments, the request may be received from a user, such as an administrator. In some embodiments, the request may be received from a client attempting to utilize the service. In some embodiments, the request may be received automatically upon a determination that the current implementation of the service is inadequate. In certain embodiments, the request may be authenticated prior to initiating the process. For example, the service application  402  may verify that the request originated with an entity that has authorization to implement the service requested. 
     At step  2  of the process  400 , the service application  402  routes the request via a routing layer  404  to the control plane  406 . The control plane may then determine whether implementation of the service is appropriate. For example, the control plane  406  may first determine whether there is unused computing resources within a cell associated with the service that is already implemented. Additionally, the control plane  406  may determine, based on metrics associated with the usage of the service, whether a client requesting the service has exceeded any limits on that service. 
     At step  3  of the process  400 , the control plane of the service application  402  determines what computing resources should be included within the cell to be implemented. To do this, the service application may retrieve profile data  407  associated with the service. In some embodiments, the control plane  406  may allocate computing resources according to the needs of a client or a group of clients. For example, the control plane may allocate additional computing power to one or more applications which are disproportionately used by the client or group of clients. In some embodiments, computing resources may be allocated based on a maturation of a client for which the cell is being implemented. Note that while a cell may be generated for a single client in some embodiments, cells may service multiple clients in other embodiments. 
     At step  4  of the process  400 , the service application  402  kicks off a number of worker threads  408 . Each of the worker threads  408  is assigned to create a shard of computing resources needed to implement the requested service from computing resources  410  available to the cloud platform. 
     At step  5  of the process  400 , a cell  412  is generated using the resource shards created by the worker threads and instantiated on at least one computing device. In some embodiments, the computing device may be selected for implementation based on a current available processing power and/or memory of that computing device. In some embodiments, one or more computing devices may be selected for implementation by virtue of not already having a version of the cell  412  implemented on it. The service application  402  records the location and status of the cell  412 . In some embodiments, a record is also kept by the service application  402  of each client using the cell  412 . 
     At step  6  of the process  400 , a client  414  may request access to the service implemented via cell  412 . A routing layer  404  first determines whether the client has authorization to access the service. Upon determining that the client  414  has authorization to access the service and has not exceeded a limit for accessing the service, the service application  402  may determine the appropriate cell to assign the client  414  to. In some embodiments, an appropriate cell may be selected based on requirements of the user. For example, the service application  402  may account for historical usage by the client of various computing resources and may assign the client  414  to a cell that is best configured to handle the client&#39;s usage. Once an appropriate cell is determined, a routing layer  404  of the service application  402  directs the client  414  to the cell  412 . 
     At step  7  of the process  400 , the client  414  is routed to the cell  412 . A client namespace  416  is reserved for the client within the cell  412 . It should be noted that the client namespace  416  may be created prior to this step, such as upon creation of the cell  412 . Note that the cell  412  may include namespaces for a number of different clients. Within the client namespace  416 , computing resources  418  related to the request are provisioned. In some embodiments, the provisioned resources  418  may be sufficient to complete the request. In some embodiments, the provisioned resources  418  may access data external to the cell  412 , such as data within a data store  420 . 
       FIG.  5    depicts a flow diagram illustrating an example process for performing a migration of data via a transaction in accordance with embodiments. The process  500  is illustrated as a logical flow diagram, each operation of which represents a sequence of operations that can be implemented in hardware, computer instructions, or a combination thereof. In the context of computer instructions, the operations represent computer-executable instructions stored on one or more computer-readable storage media that, when executed by one or more processors, perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures, and the like that perform particular functions or implement particular data types. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described operations can be omitted or combined in any order and/or in parallel to implement this process and any other processes described herein. 
     Some or all of the process  500  (or any other processes described herein, or variations and/or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions and may be implemented as code (e.g., executable instructions, one or more computer programs or one or more applications). In accordance with at least one embodiment, the process  500  of  FIG.  5    may be performed by one or more elements of the cloud platform  110  shown in  FIG.  1   . For example, the process  500  may be performed by a service application  112  as described with respect to  FIG.  1   . The code may be stored on a computer-readable storage medium, for example, in the form of a computer program including a plurality of instructions executable by one or more processors. The computer-readable storage medium may be non-transitory. 
     Process  500  begins at  502  when a cell is generated in association with a service. In some embodiments, the cell may be generated by a computing device within a cloud computing platform. The cell is generated to include at least a container engine. In some embodiments, the generated cell additionally includes a transaction processor configured to perform transactions for the number of resources associated with the service. In some embodiments, the cell generated in association with the service is one of multiple cells generated in association with the service. For example, each of the multiple cells generated in association the service may be associated with a different aspect of the service. In this example, the cells may be configured with a focus on particular functionalities or performance. In some embodiments, the cell is generated via a number of worker threads. 
     At  504 , the process  500  involves implementing computing resources within the cell. In some embodiments, the number of resources associated with the service are identified based on profile data stored in association with the cell. In some embodiments, the a number of resources associated with the service are implemented as shards. In certain embodiments, the cell comprises at least a service layer, a monitoring layer, and a data layer. The service layer includes a number of service applications that perform various functions within a cloud computing platform. The monitoring layer comprises a number of applications that track resource usage in relation the cell. The data layer comprises data to be consumed by the service layer. In some embodiments, the computing resources implemented within the cell are configured to access data in a data store located outside of the cell. 
     At  506 , the process  500  involves instantiating the cell on a number of computing devices. In some embodiments, the number of computing devices is determined based at least in part on a predicted demand for the service. 
     At  508 , the process  500  involves receiving a request from a client to access a service. In some embodiments, the request for access to the service includes an indication of one or more functionality associated with the service. In these embodiments, the instance of the cell on instantiated on the one of the number of second computing devices may be configured to provide the one or more functionality. 
     At  510 , the process  500  involves assigning the client to an instance of the cell on a computing device of the number of computing devices. In some embodiments, the client is assigned to the instance of the cell based on historical usage patterns associated with the client. The client may further be assigned to a namespace within the cell. Since the namespace can be given constraints independent of the cell in which it resides, actions taken by the client within the namespace are prevented from impacting other clients. 
     As noted above, infrastructure as a service (IaaS) is one particular type of cloud computing. IaaS can be configured to provide virtualized computing resources over a public network (e.g., the Internet). In an IaaS model, a cloud computing provider can host the infrastructure components (e.g., servers, storage devices, network nodes (e.g., hardware), deployment software, platform virtualization (e.g., a hypervisor layer), or the like). In some cases, an IaaS provider may also supply a variety of services to accompany those infrastructure components (e.g., billing, monitoring, logging, security, load balancing and clustering, etc.). Thus, as these services may be policy-driven, IaaS users may be able to implement policies to drive load balancing to maintain application availability and performance. 
     In some instances, IaaS customers may access resources and services through a wide area network (WAN), such as the Internet, and can use the cloud provider&#39;s services to install the remaining elements of an application stack. For example, the user can log in to the IaaS platform to create virtual machines (VMs), install operating systems (OSs) on each VM, deploy middleware such as databases, create storage buckets for workloads and backups, and even install enterprise software into that VM. Customers can then use the provider&#39;s services to perform various functions, including balancing network traffic, troubleshooting application issues, monitoring performance, managing disaster recovery, etc. 
     In most cases, a cloud computing model will require the participation of a cloud provider. The cloud provider may, but need not be, a third-party service that specializes in providing (e.g., offering, renting, selling) IaaS. An entity might also opt to deploy a private cloud, becoming its own provider of infrastructure services. 
     In some examples, IaaS deployment is the process of putting a new application, or a new version of an application, onto a prepared application server or the like. It may also include the process of preparing the server (e.g., installing libraries, daemons, etc.). This is often managed by the cloud provider, below the hypervisor layer (e.g., the servers, storage, network hardware, and virtualization). Thus, the customer may be responsible for handling (OS), middleware, and/or application deployment (e.g., on self-service virtual machines (e.g., that can be spun up on demand) or the like. 
     In some examples, IaaS provisioning may refer to acquiring computers or virtual hosts for use, and even installing needed libraries or services on them. In most cases, deployment does not include provisioning, and the provisioning may need to be performed first. 
     In some cases, there are two different problems for IaaS provisioning. First, there is the initial challenge of provisioning the initial set of infrastructure before anything is running. Second, there is the challenge of evolving the existing infrastructure (e.g., adding new services, changing services, removing services, etc.) once everything has been provisioned. In some cases, these two challenges may be addressed by enabling the configuration of the infrastructure to be defined declaratively. In other words, the infrastructure (e.g., what components are needed and how they interact) can be defined by one or more configuration files. Thus, the overall topology of the infrastructure (e.g., what resources depend on which, and how they each work together) can be described declaratively. In some instances, once the topology is defined, a workflow can be generated that creates and/or manages the different components described in the configuration files. 
     In some examples, an infrastructure may have many interconnected elements. For example, there may be one or more virtual private clouds (VPCs) (e.g., a potentially on-demand pool of configurable and/or shared computing resources), also known as a core network. In some examples, there may also be one or more security group rules provisioned to define how the security of the network will be set up and one or more virtual machines (VMs). Other infrastructure elements may also be provisioned, such as a load balancer, a database, or the like. As more and more infrastructure elements are desired and/or added, the infrastructure may incrementally evolve. 
     In some instances, continuous deployment techniques may be employed to enable deployment of infrastructure code across various virtual computing environments. Additionally, the described techniques can enable infrastructure management within these environments. In some examples, service teams can write code that is desired to be deployed to one or more, but often many, different production environments (e.g., across various different geographic locations, sometimes spanning the entire world). However, in some examples, the infrastructure on which the code will be deployed must first be set up. In some instances, the provisioning can be done manually, a provisioning tool may be utilized to provision the resources, and/or deployment tools may be utilized to deploy the code once the infrastructure is provisioned. 
       FIG.  6    is a block diagram  600  illustrating an example pattern of an IaaS architecture, according to at least one embodiment. Service operators  602  can be communicatively coupled to a secure host tenancy  604  that can include a virtual cloud network (VCN)  606  and a secure host subnet  608 . In some examples, the service operators  602  may be using one or more client computing devices, which may be portable handheld devices (e.g., an iPhone®, cellular telephone, an iPad®, computing tablet, a personal digital assistant (PDA)) or wearable devices (e.g., a Google Glass® head mounted display), running software such as Microsoft Windows Mobile®, and/or a variety of mobile operating systems such as iOS, Windows Phone, Android, BlackBerry 8, Palm OS, and the like, and being Internet, e-mail, short message service (SMS), Blackberry®, or other communication protocol enabled. Alternatively, the client computing devices can be general purpose personal computers including, by way of example, personal computers and/or laptop computers running various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems. The client computing devices can be workstation computers running any of a variety of commercially-available UNIX® or UNIX-like operating systems, including without limitation the variety of GNU/Linux operating systems, such as for example, Google Chrome OS. Alternatively, or in addition, client computing devices may be any other electronic device, such as a thin-client computer, an Internet-enabled gaming system (e.g., a Microsoft Xbox gaming console with or without a Kinect® gesture input device), and/or a personal messaging device, capable of communicating over a network that can access the VCN  606  and/or the Internet. 
     The VCN  606  can include a local peering gateway (LPG)  610  that can be communicatively coupled to a secure shell (SSH) VCN  612  via an LPG  610  contained in the SSH VCN  612 . The SSH VCN  612  can include an SSH subnet  614 , and the SSH VCN  612  can be communicatively coupled to a control plane VCN  616  via the LPG  610  contained in the control plane VCN  616 . Also, the SSH VCN  612  can be communicatively coupled to a data plane VCN  618  via an LPG  610 . The control plane VCN  616  and the data plane VCN  618  can be contained in a service tenancy  619  that can be owned and/or operated by the IaaS provider. 
     The control plane VCN  616  can include a control plane demilitarized zone (DMZ) tier  620  that acts as a perimeter network (e.g., portions of a corporate network between the corporate intranet and external networks). The DMZ-based servers may have restricted responsibilities and help keep security breaches contained. Additionally, the DMZ tier  620  can include one or more load balancer (LB) subnet(s)  622 , a control plane app tier  624  that can include app subnet(s)  626 , a control plane data tier  628  that can include database (DB) subnet(s)  630  (e.g., frontend DB subnet(s) and/or backend DB subnet(s)). The LB subnet(s)  622  contained in the control plane DMZ tier  620  can be communicatively coupled to the app subnet(s)  626  contained in the control plane app tier  624  and an Internet gateway  634  that can be contained in the control plane VCN  616 , and the app subnet(s)  626  can be communicatively coupled to the DB subnet(s)  630  contained in the control plane data tier  628  and a service gateway  636  and a network address translation (NAT) gateway  638 . The control plane VCN  616  can include the service gateway  636  and the NAT gateway  638 . 
     The control plane VCN  616  can include a data plane mirror app tier  640  that can include app subnet(s)  626 . The app subnet(s)  626  contained in the data plane mirror app tier  640  can include a virtual network interface controller (VNIC)  642  that can execute a compute instance  644 . The compute instance  644  can communicatively couple the app subnet(s)  626  of the data plane mirror app tier  640  to app subnet(s)  626  that can be contained in a data plane app tier  646 . 
     The data plane VCN  618  can include the data plane app tier  646 , a data plane DMZ tier  648 , and a data plane data tier  650 . The data plane DMZ tier  648  can include LB subnet(s)  622  that can be communicatively coupled to the app subnet(s)  626  of the data plane app tier  646  and the Internet gateway  634  of the data plane VCN  618 . The app subnet(s)  626  can be communicatively coupled to the service gateway  636  of the data plane VCN  618  and the NAT gateway  638  of the data plane VCN  618 . The data plane data tier  650  can also include the DB subnet(s)  630  that can be communicatively coupled to the app subnet(s)  626  of the data plane app tier  646 . 
     The Internet gateway  634  of the control plane VCN  616  and of the data plane VCN  618  can be communicatively coupled to a metadata management service  652  that can be communicatively coupled to public Internet  654 . Public Internet  654  can be communicatively coupled to the NAT gateway  638  of the control plane VCN  616  and of the data plane VCN  618 . The service gateway  636  of the control plane VCN  616  and of the data plane VCN  618  can be communicatively couple to cloud services  656 . 
     In some examples, the service gateway  636  of the control plane VCN  616  or of the data plane VCN  618  can make application programming interface (API) calls to cloud services  656  without going through public Internet  654 . The API calls to cloud services  656  from the service gateway  636  can be one-way: the service gateway  636  can make API calls to cloud services  656 , and cloud services  656  can send requested data to the service gateway  636 . But, cloud services  656  may not initiate API calls to the service gateway  636 . 
     In some examples, the secure host tenancy  604  can be directly connected to the service tenancy  619 , which may be otherwise isolated. The secure host subnet  608  can communicate with the SSH subnet  614  through an LPG  610  that may enable two-way communication over an otherwise isolated system. Connecting the secure host subnet  608  to the SSH subnet  614  may give the secure host subnet  608  access to other entities within the service tenancy  619 . 
     The control plane VCN  616  may allow users of the service tenancy  619  to set up or otherwise provision desired resources. Desired resources provisioned in the control plane VCN  616  may be deployed or otherwise used in the data plane VCN  618 . In some examples, the control plane VCN  616  can be isolated from the data plane VCN  618 , and the data plane mirror app tier  640  of the control plane VCN  616  can communicate with the data plane app tier  646  of the data plane VCN  618  via VNICs  642  that can be contained in the data plane mirror app tier  640  and the data plane app tier  646 . 
     In some examples, users of the system, or customers, can make requests, for example create, read, update, or delete (CRUD) operations, through public Internet  654  that can communicate the requests to the metadata management service  652 . The metadata management service  652  can communicate the request to the control plane VCN  616  through the Internet gateway  634 . The request can be received by the LB subnet(s)  622  contained in the control plane DMZ tier  620 . The LB subnet(s)  622  may determine that the request is valid, and in response to this determination, the LB subnet(s)  622  can transmit the request to app subnet(s)  626  contained in the control plane app tier  624 . If the request is validated and requires a call to public Internet  654 , the call to public Internet  654  may be transmitted to the NAT gateway  638  that can make the call to public Internet  654 . Memory that may be desired to be stored by the request can be stored in the DB subnet(s)  630 . 
     In some examples, the data plane mirror app tier  640  can facilitate direct communication between the control plane VCN  616  and the data plane VCN  618 . For example, changes, updates, or other suitable modifications to configuration may be desired to be applied to the resources contained in the data plane VCN  618 . Via a VNIC  642 , the control plane VCN  616  can directly communicate with, and can thereby execute the changes, updates, or other suitable modifications to configuration to, resources contained in the data plane VCN  618 . 
     In some embodiments, the control plane VCN  616  and the data plane VCN  618  can be contained in the service tenancy  619 . In this case, the user, or the customer, of the system may not own or operate either the control plane VCN  616  or the data plane VCN  618 . Instead, the IaaS provider may own or operate the control plane VCN  616  and the data plane VCN  618 , both of which may be contained in the service tenancy  619 . This embodiment can enable isolation of networks that may prevent users or customers from interacting with other users&#39;, or other customers&#39;, resources. Also, this embodiment may allow users or customers of the system to store databases privately without needing to rely on public Internet  654 , which may not have a desired level of security, for storage. 
     In other embodiments, the LB subnet(s)  622  contained in the control plane VCN  616  can be configured to receive a signal from the service gateway  636 . In this embodiment, the control plane VCN  616  and the data plane VCN  618  may be configured to be called by a customer of the IaaS provider without calling public Internet  654 . Customers of the IaaS provider may desire this embodiment since database(s) that the customers use may be controlled by the IaaS provider and may be stored on the service tenancy  619 , which may be isolated from public Internet  654 . 
       FIG.  7    is a block diagram  700  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  702  (e.g. service operators  602  of  FIG.  6   ) can be communicatively coupled to a secure host tenancy  704  (e.g. the secure host tenancy  604  of  FIG.  6   ) that can include a virtual cloud network (VCN)  706  (e.g. the VCN  606  of  FIG.  6   ) and a secure host subnet  708  (e.g. the secure host subnet  608  of  FIG.  6   ). The VCN  706  can include a local peering gateway (LPG)  710  (e.g. the LPG  610  of  FIG.  6   ) that can be communicatively coupled to a secure shell (SSH) VCN  712  (e.g. the SSH VCN  612  of  FIG.  6   ) via an LPG  610  contained in the SSH VCN  712 . The SSH VCN  712  can include an SSH subnet  714  (e.g. the SSH subnet  614  of  FIG.  6   ), and the SSH VCN  712  can be communicatively coupled to a control plane VCN  716  (e.g. the control plane VCN  616  of  FIG.  6   ) via an LPG  710  contained in the control plane VCN  716 . The control plane VCN  716  can be contained in a service tenancy  719  (e.g. the service tenancy  619  of  FIG.  6   ), and the data plane VCN  718  (e.g. the data plane VCN  618  of  FIG.  6   ) can be contained in a customer tenancy  721  that may be owned or operated by users, or customers, of the system. 
     The control plane VCN  716  can include a control plane DMZ tier  720  (e.g. the control plane DMZ tier  620  of  FIG.  6   ) that can include LB subnet(s)  722  (e.g. LB subnet(s)  622  of  FIG.  6   ), a control plane app tier  724  (e.g. the control plane app tier  624  of  FIG.  6   ) that can include app subnet(s)  726  (e.g. app subnet(s)  626  of  FIG.  6   ), a control plane data tier  728  (e.g. the control plane data tier  628  of  FIG.  6   ) that can include database (DB) subnet(s)  730  (e.g. similar to DB subnet(s)  630  of  FIG.  6   ). The LB subnet(s)  722  contained in the control plane DMZ tier  720  can be communicatively coupled to the app subnet(s)  726  contained in the control plane app tier  724  and an Internet gateway  734  (e.g. the Internet gateway  634  of  FIG.  6   ) that can be contained in the control plane VCN  716 , and the app subnet(s)  726  can be communicatively coupled to the DB subnet(s)  730  contained in the control plane data tier  728  and a service gateway  736  (e.g. the service gateway of  FIG.  6   ) and a network address translation (NAT) gateway  738  (e.g. the NAT gateway  638  of  FIG.  6   ). The control plane VCN  716  can include the service gateway  736  and the NAT gateway  738 . 
     The control plane VCN  716  can include a data plane mirror app tier  740  (e.g. the data plane mirror app tier  640  of  FIG.  6   ) that can include app subnet(s)  726 . The app subnet(s)  726  contained in the data plane mirror app tier  740  can include a virtual network interface controller (VNIC)  742  (e.g. the VNIC of  642 ) that can execute a compute instance  744  (e.g. similar to the compute instance  644  of  FIG.  6   ). The compute instance  744  can facilitate communication between the app subnet(s)  726  of the data plane mirror app tier  740  and the app subnet(s)  726  that can be contained in a data plane app tier  746  (e.g. the data plane app tier  646  of  FIG.  6   ) via the VNIC  742  contained in the data plane mirror app tier  740  and the VNIC  742  contained in the data plane app tier  746 . 
     The Internet gateway  734  contained in the control plane VCN  716  can be communicatively coupled to a metadata management service  752  (e.g. the metadata management service  652  of  FIG.  6   ) that can be communicatively coupled to public Internet  754  (e.g. public Internet  654  of  FIG.  6   ). Public Internet  754  can be communicatively coupled to the NAT gateway  738  contained in the control plane VCN  716 . The service gateway  736  contained in the control plane VCN  716  can be communicatively couple to cloud services  756  (e.g. cloud services  656  of  FIG.  6   ). 
     In some examples, the data plane VCN  718  can be contained in the customer tenancy  721 . In this case, the IaaS provider may provide the control plane VCN  716  for each customer, and the IaaS provider may, for each customer, set up a unique compute instance  744  that is contained in the service tenancy  719 . Each compute instance  744  may allow communication between the control plane VCN  716 , contained in the service tenancy  719 , and the data plane VCN  718  that is contained in the customer tenancy  721 . The compute instance  744  may allow resources, that are provisioned in the control plane VCN  716  that is contained in the service tenancy  719 , to be deployed or otherwise used in the data plane VCN  718  that is contained in the customer tenancy  721 . 
     In other examples, the customer of the IaaS provider may have databases that live in the customer tenancy  721 . In this example, the control plane VCN  716  can include the data plane mirror app tier  740  that can include app subnet(s)  726 . The data plane mirror app tier  740  can reside in the data plane VCN  718 , but the data plane mirror app tier  740  may not live in the data plane VCN  718 . That is, the data plane mirror app tier  740  may have access to the customer tenancy  721 , but the data plane mirror app tier  740  may not exist in the data plane VCN  718  or be owned or operated by the customer of the IaaS provider. The data plane mirror app tier  740  may be configured to make calls to the data plane VCN  718  but may not be configured to make calls to any entity contained in the control plane VCN  716 . The customer may desire to deploy or otherwise use resources in the data plane VCN  718  that are provisioned in the control plane VCN  716 , and the data plane mirror app tier  740  can facilitate the desired deployment, or other usage of resources, of the customer. 
     In some embodiments, the customer of the IaaS provider can apply filters to the data plane VCN  718 . In this embodiment, the customer can determine what the data plane VCN  718  can access, and the customer may restrict access to public Internet  754  from the data plane VCN  718 . The IaaS provider may not be able to apply filters or otherwise control access of the data plane VCN  718  to any outside networks or databases. Applying filters and controls by the customer onto the data plane VCN  718 , contained in the customer tenancy  721 , can help isolate the data plane VCN  718  from other customers and from public Internet  754 . 
     In some embodiments, cloud services  756  can be called by the service gateway  736  to access services that may not exist on public Internet  754 , on the control plane VCN  716 , or on the data plane VCN  718 . The connection between cloud services  756  and the control plane VCN  716  or the data plane VCN  718  may not be live or continuous. Cloud services  756  may exist on a different network owned or operated by the IaaS provider. Cloud services  756  may be configured to receive calls from the service gateway  736  and may be configured to not receive calls from public Internet  754 . Some cloud services  756  may be isolated from other cloud services  756 , and the control plane VCN  716  may be isolated from cloud services  756  that may not be in the same region as the control plane VCN  716 . For example, the control plane VCN  716  may be located in “Region 1,” and cloud service “Deployment 6,” may be located in Region 1 and in “Region 2.” If a call to Deployment 6 is made by the service gateway  736  contained in the control plane VCN  716  located in Region 1, the call may be transmitted to Deployment 6 in Region 1. In this example, the control plane VCN  716 , or Deployment 6 in Region 1, may not be communicatively coupled to, or otherwise in communication with, Deployment 6 in Region 2. 
       FIG.  8    is a block diagram  800  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  802  (e.g. service operators  602  of  FIG.  6   ) can be communicatively coupled to a secure host tenancy  804  (e.g. the secure host tenancy  604  of  FIG.  6   ) that can include a virtual cloud network (VCN)  806  (e.g. the VCN  606  of  FIG.  6   ) and a secure host subnet  808  (e.g. the secure host subnet  608  of  FIG.  6   ). The VCN  806  can include an LPG  810  (e.g. the LPG  610  of  FIG.  6   ) that can be communicatively coupled to an SSH VCN  812  (e.g. the SSH VCN  612  of  FIG.  6   ) via an LPG  810  contained in the SSH VCN  812 . The SSH VCN  812  can include an SSH subnet  814  (e.g. the SSH subnet  614  of  FIG.  6   ), and the SSH VCN  812  can be communicatively coupled to a control plane VCN  816  (e.g. the control plane VCN  616  of  FIG.  6   ) via an LPG  810  contained in the control plane VCN  816  and to a data plane VCN  818  (e.g. the data plane  618  of  FIG.  6   ) via an LPG  810  contained in the data plane VCN  818 . The control plane VCN  816  and the data plane VCN  818  can be contained in a service tenancy  819  (e.g. the service tenancy  619  of  FIG.  6   ). 
     The control plane VCN  816  can include a control plane DMZ tier  820  (e.g. the control plane DMZ tier  620  of  FIG.  6   ) that can include load balancer (LB) subnet(s)  822  (e.g. LB subnet(s)  622  of  FIG.  6   ), a control plane app tier  824  (e.g. the control plane app tier  624  of  FIG.  6   ) that can include app subnet(s)  826  (e.g. similar to app subnet(s)  626  of  FIG.  6   ), a control plane data tier  828  (e.g. the control plane data tier  628  of  FIG.  6   ) that can include DB subnet(s)  830 . The LB subnet(s)  822  contained in the control plane DMZ tier  820  can be communicatively coupled to the app subnet(s)  826  contained in the control plane app tier  824  and to an Internet gateway  834  (e.g. the Internet gateway  634  of  FIG.  6   ) that can be contained in the control plane VCN  816 , and the app subnet(s)  826  can be communicatively coupled to the DB subnet(s)  830  contained in the control plane data tier  828  and to a service gateway  836  (e.g. the service gateway of  FIG.  6   ) and a network address translation (NAT) gateway  838  (e.g. the NAT gateway  638  of  FIG.  6   ). The control plane VCN  816  can include the service gateway  836  and the NAT gateway  838 . 
     The data plane VCN  818  can include a data plane app tier  846  (e.g. the data plane app tier  646  of  FIG.  6   ), a data plane DMZ tier  848  (e.g. the data plane DMZ tier  648  of  FIG.  6   ), and a data plane data tier  850  (e.g. the data plane data tier  650  of  FIG.  6   ). The data plane DMZ tier  848  can include LB subnet(s)  822  that can be communicatively coupled to trusted app subnet(s)  860  and untrusted app subnet(s)  862  of the data plane app tier  846  and the Internet gateway  834  contained in the data plane VCN  818 . The trusted app subnet(s)  860  can be communicatively coupled to the service gateway  836  contained in the data plane VCN  818 , the NAT gateway  838  contained in the data plane VCN  818 , and DB subnet(s)  830  contained in the data plane data tier  850 . The untrusted app subnet(s)  862  can be communicatively coupled to the service gateway  836  contained in the data plane VCN  818  and DB subnet(s)  830  contained in the data plane data tier  850 . The data plane data tier  850  can include DB subnet(s)  830  that can be communicatively coupled to the service gateway  836  contained in the data plane VCN  818 . 
     The untrusted app subnet(s)  862  can include one or more primary VNICs  864 ( 1 )-(N) that can be communicatively coupled to tenant virtual machines (VMs)  866 ( 1 )-(N). Each tenant VM  866 ( 1 )-(N) can be communicatively coupled to a respective app subnet  867 ( 1 )-(N) that can be contained in respective container egress VCNs  868 ( 1 )-(N) that can be contained in respective customer tenancies  870 ( 1 )-(N). Respective secondary VNICs  872 ( 1 )-(N) can facilitate communication between the untrusted app subnet(s)  862  contained in the data plane VCN  818  and the app subnet contained in the container egress VCNs  868 ( 1 )-(N). Each container egress VCNs  868 ( 1 )-(N) can include a NAT gateway  838  that can be communicatively coupled to public Internet  854  (e.g. public Internet  654  of  FIG.  6   ). 
     The Internet gateway  834  contained in the control plane VCN  816  and contained in the data plane VCN  818  can be communicatively coupled to a metadata management service  852  (e.g. the metadata management system  652  of  FIG.  6   ) that can be communicatively coupled to public Internet  854 . Public Internet  854  can be communicatively coupled to the NAT gateway  838  contained in the control plane VCN  816  and contained in the data plane VCN  818 . The service gateway  836  contained in the control plane VCN  816  and contained in the data plane VCN  818  can be communicatively couple to cloud services  856 . 
     In some embodiments, the data plane VCN  818  can be integrated with customer tenancies  870 . This integration can be useful or desirable for customers of the IaaS provider in some cases such as a case that may desire support when executing code. The customer may provide code to run that may be destructive, may communicate with other customer resources, or may otherwise cause undesirable effects. In response to this, the IaaS provider may determine whether to run code given to the IaaS provider by the customer. 
     In some examples, the customer of the IaaS provider may grant temporary network access to the IaaS provider and request a function to be attached to the data plane tier app  846 . Code to run the function may be executed in the VMs  866 ( 1 )-(N), and the code may not be configured to run anywhere else on the data plane VCN  818 . Each VM  866 ( 1 )-(N) may be connected to one customer tenancy  870 . Respective containers  871 ( 1 )-(N) contained in the VMs  866 ( 1 )-(N) may be configured to run the code. In this case, there can be a dual isolation (e.g., the containers  871 ( 1 )-(N) running code, where the containers  871 ( 1 )-(N) may be contained in at least the VM  866 ( 1 )-(N) that are contained in the untrusted app subnet(s)  862 ), which may help prevent incorrect or otherwise undesirable code from damaging the network of the IaaS provider or from damaging a network of a different customer. The containers  871 ( 1 )-(N) may be communicatively coupled to the customer tenancy  870  and may be configured to transmit or receive data from the customer tenancy  870 . The containers  871 ( 1 )-(N) may not be configured to transmit or receive data from any other entity in the data plane VCN  818 . Upon completion of running the code, the IaaS provider may kill or otherwise dispose of the containers  871 ( 1 )-(N). 
     In some embodiments, the trusted app subnet(s)  860  may run code that may be owned or operated by the IaaS provider. In this embodiment, the trusted app subnet(s)  860  may be communicatively coupled to the DB subnet(s)  830  and be configured to execute CRUD operations in the DB subnet(s)  830 . The untrusted app subnet(s)  862  may be communicatively coupled to the DB subnet(s)  830 , but in this embodiment, the untrusted app subnet(s) may be configured to execute read operations in the DB subnet(s)  830 . The containers  871 ( 1 )-(N) that can be contained in the VM  866 ( 1 )-(N) of each customer and that may run code from the customer may not be communicatively coupled with the DB subnet(s)  830 . 
     In other embodiments, the control plane VCN  816  and the data plane VCN  818  may not be directly communicatively coupled. In this embodiment, there may be no direct communication between the control plane VCN  816  and the data plane VCN  818 . However, communication can occur indirectly through at least one method. An LPG  810  may be established by the IaaS provider that can facilitate communication between the control plane VCN  816  and the data plane VCN  818 . In another example, the control plane VCN  816  or the data plane VCN  818  can make a call to cloud services  856  via the service gateway  836 . For example, a call to cloud services  856  from the control plane VCN  816  can include a request for a service that can communicate with the data plane VCN  818 . 
       FIG.  9    is a block diagram  900  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  902  (e.g. service operators  602  of  FIG.  6   ) can be communicatively coupled to a secure host tenancy  904  (e.g. the secure host tenancy  604  of  FIG.  6   ) that can include a virtual cloud network (VCN)  906  (e.g. the VCN  606  of  FIG.  6   ) and a secure host subnet  908  (e.g. the secure host subnet  608  of  FIG.  6   ). The VCN  906  can include an LPG  910  (e.g. the LPG  610  of  FIG.  6   ) that can be communicatively coupled to an SSH VCN  912  (e.g. the SSH VCN  612  of  FIG.  6   ) via an LPG  910  contained in the SSH VCN  912 . The SSH VCN  912  can include an SSH subnet  914  (e.g. the SSH subnet  614  of  FIG.  6   ), and the SSH VCN  912  can be communicatively coupled to a control plane VCN  916  (e.g. the control plane VCN  616  of  FIG.  6   ) via an LPG  910  contained in the control plane VCN  916  and to a data plane VCN  918  (e.g. the data plane  618  of  FIG.  6   ) via an LPG  910  contained in the data plane VCN  918 . The control plane VCN  916  and the data plane VCN  918  can be contained in a service tenancy  919  (e.g. the service tenancy  619  of  FIG.  6   ). 
     The control plane VCN  916  can include a control plane DMZ tier  920  (e.g. the control plane DMZ tier  620  of  FIG.  6   ) that can include LB subnet(s)  922  (e.g. LB subnet(s)  622  of  FIG.  6   ), a control plane app tier  924  (e.g. the control plane app tier  624  of  FIG.  6   ) that can include app subnet(s)  926  (e.g. app subnet(s)  626  of  FIG.  6   ), a control plane data tier  928  (e.g. the control plane data tier  628  of  FIG.  6   ) that can include DB subnet(s)  930  (e.g. DB subnet(s)  830  of  FIG.  8   ). The LB subnet(s)  922  contained in the control plane DMZ tier  920  can be communicatively coupled to the app subnet(s)  926  contained in the control plane app tier  924  and to an Internet gateway  934  (e.g. the Internet gateway  634  of  FIG.  6   ) that can be contained in the control plane VCN  916 , and the app subnet(s)  926  can be communicatively coupled to the DB subnet(s)  930  contained in the control plane data tier  928  and to a service gateway  936  (e.g. the service gateway of  FIG.  6   ) and a network address translation (NAT) gateway  938  (e.g. the NAT gateway  638  of  FIG.  6   ). The control plane VCN  916  can include the service gateway  936  and the NAT gateway  938 . 
     The data plane VCN  918  can include a data plane app tier  946  (e.g. the data plane app tier  646  of  FIG.  6   ), a data plane DMZ tier  948  (e.g. the data plane DMZ tier  648  of  FIG.  6   ), and a data plane data tier  950  (e.g. the data plane data tier  650  of  FIG.  6   ). The data plane DMZ tier  948  can include LB subnet(s)  922  that can be communicatively coupled to trusted app subnet(s)  960  (e.g. trusted app subnet(s)  860  of  FIG.  8   ) and untrusted app subnet(s)  962  (e.g. untrusted app subnet(s)  862  of  FIG.  8   ) of the data plane app tier  946  and the Internet gateway  934  contained in the data plane VCN  918 . The trusted app subnet(s)  960  can be communicatively coupled to the service gateway  936  contained in the data plane VCN  918 , the NAT gateway  938  contained in the data plane VCN  918 , and DB subnet(s)  930  contained in the data plane data tier  950 . The untrusted app subnet(s)  962  can be communicatively coupled to the service gateway  936  contained in the data plane VCN  918  and DB subnet(s)  930  contained in the data plane data tier  950 . The data plane data tier  950  can include DB subnet(s)  930  that can be communicatively coupled to the service gateway  936  contained in the data plane VCN  918 . 
     The untrusted app subnet(s)  962  can include primary VNICs  964 ( 1 )-(N) that can be communicatively coupled to tenant virtual machines (VMs)  966 ( 1 )-(N) residing within the untrusted app subnet(s)  962 . Each tenant VM  966 ( 1 )-(N) can run code in a respective container  967 ( 1 )-(N), and be communicatively coupled to an app subnet  926  that can be contained in a data plane app tier  946  that can be contained in a container egress VCN  968 . Respective secondary VNICs  972 ( 1 )-(N) can facilitate communication between the untrusted app subnet(s)  962  contained in the data plane VCN  918  and the app subnet contained in the container egress VCN  968 . The container egress VCN can include a NAT gateway  938  that can be communicatively coupled to public Internet  954  (e.g. public Internet  654  of  FIG.  6   ). 
     The Internet gateway  934  contained in the control plane VCN  916  and contained in the data plane VCN  918  can be communicatively coupled to a metadata management service  952  (e.g. the metadata management system  652  of  FIG.  6   ) that can be communicatively coupled to public Internet  954 . Public Internet  954  can be communicatively coupled to the NAT gateway  938  contained in the control plane VCN  916  and contained in the data plane VCN  918 . The service gateway  936  contained in the control plane VCN  916  and contained in the data plane VCN  918  can be communicatively couple to cloud services  956 . 
     In some examples, the pattern illustrated by the architecture of block diagram  900  of  FIG.  9    may be considered an exception to the pattern illustrated by the architecture of block diagram  800  of  FIG.  8    and may be desirable for a customer of the IaaS provider if the IaaS provider cannot directly communicate with the customer (e.g., a disconnected region). The respective containers  967 ( 1 )-(N) that are contained in the VMs  966 ( 1 )-(N) for each customer can be accessed in real-time by the customer. The containers  967 ( 1 )-(N) may be configured to make calls to respective secondary VNICs  972 ( 1 )-(N) contained in app subnet(s)  926  of the data plane app tier  946  that can be contained in the container egress VCN  968 . The secondary VNICs  972 ( 1 )-(N) can transmit the calls to the NAT gateway  938  that may transmit the calls to public Internet  954 . In this example, the containers  967 ( 1 )-(N) that can be accessed in real-time by the customer can be isolated from the control plane VCN  916  and can be isolated from other entities contained in the data plane VCN  918 . The containers  967 ( 1 )-(N) may also be isolated from resources from other customers. 
     In other examples, the customer can use the containers  967 ( 1 )-(N) to call cloud services  956 . In this example, the customer may run code in the containers  967 ( 1 )-(N) that requests a service from cloud services  956 . The containers  967 ( 1 )-(N) can transmit this request to the secondary VNICs  972 ( 1 )-(N) that can transmit the request to the NAT gateway that can transmit the request to public Internet  954 . Public Internet  954  can transmit the request to LB subnet(s)  922  contained in the control plane VCN  916  via the Internet gateway  934 . In response to determining the request is valid, the LB subnet(s) can transmit the request to app subnet(s)  926  that can transmit the request to cloud services  956  via the service gateway  936 . 
     It should be appreciated that IaaS architectures  600 ,  700 ,  800 ,  900  depicted in the figures may have other components than those depicted. Further, the embodiments shown in the figures are only some examples of a cloud infrastructure system that may incorporate an embodiment of the disclosure. In some other embodiments, the IaaS systems may have more or fewer components than shown in the figures, may combine two or more components, or may have a different configuration or arrangement of components. 
     In certain embodiments, the IaaS systems described herein may include a suite of applications, middleware, and database service offerings that are delivered to a customer in a self-service, subscription-based, elastically scalable, reliable, highly available, and secure manner. An example of such an IaaS system is the Oracle Cloud Infrastructure (OCI) provided by the present assignee. 
       FIG.  10    illustrates an example computer system  1000 , in which various embodiments may be implemented. The system  1000  may be used to implement any of the computer systems described above. As shown in the figure, computer system  1000  includes a processing unit  1004  that communicates with a number of peripheral subsystems via a bus subsystem  1002 . These peripheral subsystems may include a processing acceleration unit  1006 , an I/O subsystem  1008 , a storage subsystem  1018  and a communications subsystem  1024 . Storage subsystem  1018  includes tangible computer-readable storage media  1022  and a system memory  1010 . 
     Bus subsystem  1002  provides a mechanism for letting the various components and subsystems of computer system  1000  communicate with each other as intended. Although bus subsystem  1002  is shown schematically as a single bus, alternative embodiments of the bus subsystem may utilize multiple buses. Bus subsystem  1002  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. For example, such architectures may include an Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus, which can be implemented as a Mezzanine bus manufactured to the IEEE P1386.1 standard. 
     Processing unit  1004 , which can be implemented as one or more integrated circuits (e.g., a conventional microprocessor or microcontroller), controls the operation of computer system  1000 . One or more processors may be included in processing unit  1004 . These processors may include single core or multicore processors. In certain embodiments, processing unit  1004  may be implemented as one or more independent processing units  1032  and/or  1034  with single or multicore processors included in each processing unit. In other embodiments, processing unit  1004  may also be implemented as a quad-core processing unit formed by integrating two dual-core processors into a single chip. 
     In various embodiments, processing unit  1004  can execute a variety of programs in response to program code and can maintain multiple concurrently executing programs or processes. At any given time, some or all of the program code to be executed can be resident in processor(s)  1004  and/or in storage subsystem  1018 . Through suitable programming, processor(s)  1004  can provide various functionalities described above. Computer system  1000  may additionally include a processing acceleration unit  1006 , which can include a digital signal processor (DSP), a special-purpose processor, and/or the like. 
     I/O subsystem  1008  may include user interface input devices and user interface output devices. User interface input devices may include a keyboard, pointing devices such as a mouse or trackball, a touchpad or touch screen incorporated into a display, a scroll wheel, a click wheel, a dial, a button, a switch, a keypad, audio input devices with voice command recognition systems, microphones, and other types of input devices. User interface input devices may include, for example, motion sensing and/or gesture recognition devices such as the Microsoft Kinect® motion sensor that enables users to control and interact with an input device, such as the Microsoft Xbox®  360  game controller, through a natural user interface using gestures and spoken commands. User interface input devices may also include eye gesture recognition devices such as the Google Glass® blink detector that detects eye activity (e.g., ‘blinking’ while taking pictures and/or making a menu selection) from users and transforms the eye gestures as input into an input device (e.g., Google Glass®). Additionally, user interface input devices may include voice recognition sensing devices that enable users to interact with voice recognition systems (e.g., Siri® navigator), through voice commands. 
     User interface input devices may also include, without limitation, three dimensional (3D) mice, joysticks or pointing sticks, gamepads and graphic tablets, and audio/visual devices such as speakers, digital cameras, digital camcorders, portable media players, webcams, image scanners, fingerprint scanners, barcode reader 3D scanners, 3D printers, laser rangefinders, and eye gaze tracking devices. Additionally, user interface input devices may include, for example, medical imaging input devices such as computed tomography, magnetic resonance imaging, position emission tomography, medical ultrasonography devices. User interface input devices may also include, for example, audio input devices such as MIDI keyboards, digital musical instruments and the like. 
     User interface output devices may include a display subsystem, indicator lights, or non-visual displays such as audio output devices, etc. The display subsystem may be a cathode ray tube (CRT), a flat-panel device, such as that using a liquid crystal display (LCD) or plasma display, a projection device, a touch screen, and the like. In general, use of the term “output device” is intended to include all possible types of devices and mechanisms for outputting information from computer system  1000  to a user or other computer. For example, user interface output devices may include, without limitation, a variety of display devices that visually convey text, graphics and audio/video information such as monitors, printers, speakers, headphones, automotive navigation systems, plotters, voice output devices, and modems. 
     Computer system  1000  may comprise a storage subsystem  1018  that comprises software elements, shown as being currently located within a system memory  1010 . System memory  1010  may store program instructions that are loadable and executable on processing unit  1004 , as well as data generated during the execution of these programs. 
     Depending on the configuration and type of computer system  1000 , system memory  1010  may be volatile (such as random access memory (RAM)) and/or non-volatile (such as read-only memory (ROM), flash memory, etc.) The RAM typically contains data and/or program modules that are immediately accessible to and/or presently being operated and executed by processing unit  1004 . In some implementations, system memory  1010  may include multiple different types of memory, such as static random access memory (SRAM) or dynamic random access memory (DRAM). In some implementations, a basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within computer system  1000 , such as during start-up, may typically be stored in the ROM. By way of example, and not limitation, system memory  1010  also illustrates application programs  1012 , which may include client applications, Web browsers, mid-tier applications, relational database management systems (RDBMS), etc., program data  1014 , and an operating system  1016 . By way of example, operating system  1016  may include various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems, a variety of commercially-available UNIX® or UNIX-like operating systems (including without limitation the variety of GNU/Linux operating systems, the Google Chrome® OS, and the like) and/or mobile operating systems such as iOS, Windows® Phone, Android® OS, BlackBerry® 10 OS, and Palm® OS operating systems. 
     Storage subsystem  1018  may also provide a tangible computer-readable storage medium for storing the basic programming and data constructs that provide the functionality of some embodiments. Software (programs, code modules, instructions) that when executed by a processor provide the functionality described above may be stored in storage subsystem  1018 . These software modules or instructions may be executed by processing unit  1004 . Storage subsystem  1018  may also provide a repository for storing data used in accordance with the present disclosure. 
     Storage subsystem  1000  may also include a computer-readable storage media reader  1020  that can further be connected to computer-readable storage media  1022 . Together and, optionally, in combination with system memory  1010 , computer-readable storage media  1022  may comprehensively represent remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing, storing, transmitting, and retrieving computer-readable information. 
     Computer-readable storage media  1022  containing code, or portions of code, can also include any appropriate media known or used in the art, including storage media and communication media, such as but not limited to, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage and/or transmission of information. This can include tangible computer-readable storage media such as RAM, ROM, electronically erasable programmable ROM (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disk (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other tangible computer readable media. This can also include nontangible computer-readable media, such as data signals, data transmissions, or any other medium which can be used to transmit the desired information and which can be accessed by computing system  1000 . 
     By way of example, computer-readable storage media  1022  may include a hard disk drive that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive that reads from or writes to a removable, nonvolatile magnetic disk, and an optical disk drive that reads from or writes to a removable, nonvolatile optical disk such as a CD ROM, DVD, and Blu-Ray® disk, or other optical media. Computer-readable storage media  1022  may include, but is not limited to, Zip® drives, flash memory cards, universal serial bus (USB) flash drives, secure digital (SD) cards, DVD disks, digital video tape, and the like. Computer-readable storage media  1022  may also include, solid-state drives (SSD) based on non-volatile memory such as flash-memory based SSDs, enterprise flash drives, solid state ROM, and the like, SSDs based on volatile memory such as solid state RAM, dynamic RAM, static RAM, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs, and hybrid SSDs that use a combination of DRAM and flash memory based SSDs. The disk drives and their associated computer-readable media may provide non-volatile storage of computer-readable instructions, data structures, program modules, and other data for computer system  1000 . 
     Communications subsystem  1024  provides an interface to other computer systems and networks. Communications subsystem  1024  serves as an interface for receiving data from and transmitting data to other systems from computer system  1000 . For example, communications subsystem  1024  may enable computer system  1000  to connect to one or more devices via the Internet. In some embodiments communications subsystem  1024  can include radio frequency (RF) transceiver components for accessing wireless voice and/or data networks (e.g., using cellular telephone technology, advanced data network technology, such as 3G, 4G or EDGE (enhanced data rates for global evolution), WiFi (IEEE 802.11 family standards, or other mobile communication technologies, or any combination thereof), global positioning system (GPS) receiver components, and/or other components. In some embodiments communications subsystem  1024  can provide wired network connectivity (e.g., Ethernet) in addition to or instead of a wireless interface. 
     In some embodiments, communications subsystem  1024  may also receive input communication in the form of structured and/or unstructured data feeds  1026 , event streams  1028 , event updates  1030 , and the like on behalf of one or more users who may use computer system  1000 . 
     By way of example, communications subsystem  1024  may be configured to receive data feeds  1026  in real-time from users of social networks and/or other communication services such as Twitter® feeds, Facebook® updates, web feeds such as Rich Site Summary (RSS) feeds, and/or real-time updates from one or more third party information sources. 
     Additionally, communications subsystem  1024  may also be configured to receive data in the form of continuous data streams, which may include event streams  1028  of real-time events and/or event updates  1030 , that may be continuous or unbounded in nature with no explicit end. Examples of applications that generate continuous data may include, for example, sensor data applications, financial tickers, network performance measuring tools (e.g. network monitoring and traffic management applications), clickstream analysis tools, automobile traffic monitoring, and the like. 
     Communications subsystem  1024  may also be configured to output the structured and/or unstructured data feeds  1026 , event streams  1028 , event updates  1030 , and the like to one or more databases that may be in communication with one or more streaming data source computers coupled to computer system  1000 . 
     Computer system  1000  can be one of various types, including a handheld portable device (e.g., an iPhone® cellular phone, an iPad® computing tablet, a PDA), a wearable device (e.g., a Google Glass® head mounted display), a PC, a workstation, a mainframe, a kiosk, a server rack, or any other data processing system. 
     Due to the ever-changing nature of computers and networks, the description of computer system  1000  depicted in the figure is intended only as a specific example. Many other configurations having more or fewer components than the system depicted in the figure are possible. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, firmware, software (including applets), or a combination. Further, connection to other computing devices, such as network input/output devices, may be employed. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will appreciate other ways and/or methods to implement the various embodiments. 
     Although specific embodiments have been described, various modifications, alterations, alternative constructions, and equivalents are also encompassed within the scope of the disclosure. Embodiments are not restricted to operation within certain specific data processing environments, but are free to operate within a plurality of data processing environments. Additionally, although embodiments have been described using a particular series of transactions and steps, it should be apparent to those skilled in the art that the scope of the present disclosure is not limited to the described series of transactions and steps. Various features and aspects of the above-described embodiments may be used individually or jointly. 
     Further, while embodiments have been described using a particular combination of hardware and software, it should be recognized that other combinations of hardware and software are also within the scope of the present disclosure. Embodiments may be implemented only in hardware, or only in software, or using combinations thereof. The various processes described herein can be implemented on the same processor or different processors in any combination. Accordingly, where components or modules are described as being configured to perform certain operations, such configuration can be accomplished, e.g., by designing electronic circuits to perform the operation, by programming programmable electronic circuits (such as microprocessors) to perform the operation, or any combination thereof. Processes can communicate using a variety of techniques including but not limited to conventional techniques for inter process communication, and different pairs of processes may use different techniques, or the same pair of processes may use different techniques at different times. 
     The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that additions, subtractions, deletions, and other modifications and changes may be made thereunto without departing from the broader spirit and scope as set forth in the claims. Thus, although specific disclosure embodiments have been described, these are not intended to be limiting. Various modifications and equivalents are within the scope of the following claims. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosed embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure. 
     Disjunctive language such as the phrase “at least one of X, Y, or Z,” unless specifically stated otherwise, is intended to be understood within the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present. 
     Preferred embodiments of this disclosure are described herein, including the best mode known for carrying out the disclosure. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. Those of ordinary skill should be able to employ such variations as appropriate and the disclosure may be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     In the foregoing specification, aspects of the disclosure are described with reference to specific embodiments thereof, but those skilled in the art will recognize that the disclosure is not limited thereto. Various features and aspects of the above-described disclosure may be used individually or jointly. Further, embodiments can be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. The specification and drawings are, accordingly, to be regarded as illustrative rather than restrictive.