Patent Publication Number: US-7721287-B2

Title: Organizing transmission of repository data

Description:
TECHNICAL FIELD 
   This description relates to organizing a transmission of data from a repository. 
   BACKGROUND 
   Many computer systems use repositories for holding data that the system uses in its operations. In an enterprise resource planning system, the data may relate to the ongoing business operations performed in the system. Systems can have great volumes of data electronically stored in repositories, and this data can be updated at regular or arbitrary intervals. 
   In systems with great amounts of repository data, it becomes very important to provide adequate search functions for users to access the data. The system may include a search engine or equivalent providing search functionality for relevant documents according to a variety of criteria. A search engine typically has associated with it an index of repository contents. When a user enters a search query, the engine consults the index to determine whether there are any matches. In response, the search engine may send a “hit list” that enables the user to access any responsive data, for example in the form of a document. The process of creating the index based on the repository data is usually referred to as indexing. 
   When a new index is to be created, an initial indexing process is performed on the entire contents of one or more data repositories. In the case of a repository containing a large volume of data or from multiple distributed repositories, the indexing can take quite some time, up to a full day or more depending on system size. This may cause system resources to be unavailable or slow for a significant amount of time. Particularly, one bottleneck in this initial indexing process may be the step of transmitting the data from the repository to the service or equivalent that performs the indexing. It always takes a finite time to access one or more knowledge entities in the repository and to transmit the retrieved data to the indexing service. Moreover, the retrieval process may suffer from partially failed retrievals, for example when documents cannot be found where expected. 
   In existing systems, the transmission of repository data to a data recipient, such as an indexing service, may be performed in a sequential batch data retrieval process. Such a process is used in some products available from SAP AG in Walldorf (Baden), Germany. One disadvantage with this process is that it can be held up by a single batch of data that takes a long time to retrieve from the repository and/or to transmit to the indexing service. Such a delay means that it will occupy the system resource, and other indexes must wait longer until the index is finished, or in the case of an index being updated, that the content of the index will not be updated for a longer time. Moreover, such systems do not have a sophisticated solution for handling failed batch jobs efficiently. 
   If the indexing process takes a long time, this reduces system efficiency and delays the moment when the new index is ready to use. For this reason, indexing jobs that involve transmitting large amounts of data typically are run at times when system use is low, such as overnight or on weekends. In contrast, the process of later updating the index with changes in the repository data may take relatively less time, because it may be possible to focus the update indexing on only the knowledge entities that have changed since the index was created, a so-called delta update. Nevertheless, also this process can impact system performance if it involves a great volume of repository data, and the index content typically is not updated for search. 
   SUMMARY 
   The invention relates to organizing transmission of repository data. 
   In a first general aspect, a method comprises receiving, in a computer system, a request to transmit data from a data repository to a data recipient. The data is to be transmitted by executing batch jobs that each identify a data amount to be transmitted to the data recipient. Control parameters are individually assigned to each of the batch jobs. Upon detecting during transmission that a performance parameter of the computer system does not meet a predefined standard, the data amount identified by at least one of the batch jobs is automatically changed in accordance with the control parameter assigned to the at least one of the batch jobs. 
   In selected embodiments, automatically changing the data amount that is identified by at least one of the batch jobs comprises splitting the batch job into at least two batch jobs, or merging the batch job with another batch job. 
   The control parameter may specify that the at least one of the batch jobs can be divided into a number of batch subjobs. The control parameter may specify that the at least one of the batch jobs can be divided into a number of levels of batch subjobs. The control parameter may specify that the data amount identified by the at least one of the batch jobs can include a number of knowledge entities. The control parameter may specify a volume of the data amount identified by the at least one of the batch jobs. The control parameter may be a permitted range for the volume of the data amount. The control parameter may be the predefined standard. 
   In selected embodiments, assigning the control parameters comprises performing an optimization operation. The optimization operation may involve solving a constraint optimization problem. 
   In a second general aspect, a method comprises receiving, in a computer system, a request to transmit data from a data repository to a data recipient. Control parameters are individually assigned to a number of batch jobs for transmitting the data. Each of the batch jobs identifies a data amount that is to be transmitted to the data recipient. A performance parameter of the computer system is monitored while performing the batch jobs to determine whether the performance parameter does not meet a predefined standard. Upon detecting during transmission that the performance parameter does not meet the predefined standard, the control parameter of at least one of the batch jobs is evaluated to determine whether an additional batch job should be created. The additional batch job is created if the control parameter of the at least one of the batch jobs indicates that the additional batch job should be created. 
   Advantages of the systems and techniques described herein may include any or all of the following. Providing improved organization of a transmission of repository data. Providing an improved data transmission flexibility by individually assigning control parameters to batch jobs. Optimizing data transmission by taking into account relevant system characteristics. Providing an improved repository data transmission by dynamically changing the number of batch jobs being executed during the transmission. 
   The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of a system that organizes a transmission of repository data; 
       FIG. 2  is an example of components included in the system shown in  FIG. 1 ; 
       FIG. 3  schematically shows merging and splitting of batch jobs; 
       FIG. 4  is a flow chart of an embodiment of an inventive method; and 
       FIG. 5  is a block diagram of a general computer system. 
   

   Like reference numerals in the various drawings indicate like elements. 
   DETAILED DESCRIPTION 
     FIG. 1  is a block diagram of a system  100  that organizes a transmission of repository data from one or more data repositories  102  to a data recipient. Any or all of the data repositories may include a server device on which a data source is available. In this example, the data recipient is an indexing service  104  that will perform indexing for one or more search engines  106 , each of which may have associated with it an index  108 . 
   The data transmission may be initiated upon receiving a request from a user or from an automatically scheduled task. The indexing to be performed may be an initial indexing, meaning that the entire contents of one or more of the repositories  102  is being transferred. Another example is a periodic indexing wherein only the changed repository data is being transmitted. Yet another example is an automatic indexing when the original data are changed. 
   The indexing service  104  is here included in an intelligent indexing system  110  that communicates with the data repository  102  and the search engine  104 . The intelligent indexing system  110  includes a knowledge retrieval service  112  that retrieves data from the repository  102 . A concurrent indexing engine  114  creates batch jobs for transmitting the data, each of the batch jobs identifying a data amount that is to be transmitted to the recipient. When the concurrent indexing engine performs a batch job, it may trigger the knowledge retrieval service to retrieve the entire data amount that corresponds to the batch job. As another example, the concurrent indexing engine may successively trigger the knowledge retrieval service to retrieve portions of the batch job&#39;s data amount until the batch job is finished. 
   The data in the repository  102  may be of many different kinds. The data is embodied in at least one form, and this form is generally being referred to as a knowledge entity. Examples of knowledge entities include business transaction data, accounting records, business documents, sales orders, service orders, contact records, partner records or web pages. Other types of documents may be used. The transmission may involve knowledge entities that belong to a single or several different document types. Moreover, the same types of knowledge entities may be located in separate data repositories, such as when a multinational organization stores company records in several countries. 
   During transmission, the intelligent indexing system  110  monitors a performance parameter of the system  100 . If the performance parameter does not meet a predefined standard during the transmission, the intelligent indexing system may evaluate whether to automatically change the data amount that is identified by at least one of the batch jobs. More than one performance parameter may be monitored simultaneously. Also, different performance parameters may be monitored in different situations. Particularly, processing times per knowledge entity for the batch jobs, the amount of data processed per unit of time, an average processing time for the complete index cycle from retrieval to index update, a request-response time of another business application or combinations thereof, are examples of performance parameters. When batch jobs are performed by successfully retrieving portions of the batch job&#39;s data amount from the data repository, the performance parameter may be evaluated in association with retrieving each such portion. 
   A change in the data amount identified by a batch job may involve splitting a batch job into two or more batch jobs executed in parallel. Generally, the system may be able to process the data amount more quickly if it is distributed among more batch jobs. For example, with more batch jobs the system can initiate several retrievals essentially simultaneously from the data repositories  102 , as opposed to processing them consecutively in a single batch job. On the other hand, creating additional batch jobs may increase memory use in the system  100  and, if memory availability is low, the additional memory use may decrease the system&#39;s overall performance. Accordingly, before performing a split operation the intelligent indexing system  110  may determine whether the system  100  tolerates an increased memory use. For a distributed-repository case, another restriction, such as availability or maximal allowed data connections between the server and the external data repository, may be considered. 
   As another example, a change in batch job data amount may involve merging a batch job with at least another batch job. Generally, merging batch jobs may free up system resources such as memory for other purposes. Also, with fewer batch jobs in progress the system may be able to perform more processing that is unrelated to the indexing, such as processing for an application program with which a user is working. Accordingly, when a performance parameter does not meet a predefined standard, the intelligent indexing system  110  may perform a merger operation upon detecting that the system does not tolerate an increased memory use. 
   Thus, the system  100  transmits the data to the indexing service  104  by performing the batch jobs, and the data amounts identified by the respective batch jobs can be changed during the transmission. The indexing service parses through the received data and creates or updates the index  108 . When the indexing is complete, the index is made available in the system so that the search engine(s) can perform searches on it. 
     FIG. 2  is a block diagram of components that can be included in the system  100 , and particularly in the concurrent indexing engine  114 . When the system receives a request to transmit data from the data repository  102  to the indexing service  104 , the request is evaluated by a dispatch service  200  within the concurrent indexing engine. The dispatch service may determine a size of the data to be transmitted. This may be done by a programming call, for example by checking the size of a database table to determine how many knowledge entities are in the data load. The dispatch service creates a task for the requested transmission job and enters the task in one of multiple queues  202 . The multiple queues may already contain one or more transmission job tasks. Particularly, the dispatch service may check whether the newly created task is dependent on a task that is already pending. For example, processing a clustering request before a delta update request, a fail-recovery request, or before deleting an index may not be efficient. Other examples of dependencies may involve having multiple same full-indexing requests or fail-recovery requests in the same queue. The dispatch service may automatically withdraw or rearrange requests based on a set of pre-defined business rules. Alternatively, the dispatch may provide a warning to a user and wait for the user&#39;s decision. The dispatch service can register a time stamp for the task. Such a time stamp can later be used in determining whether tasks are being promptly executed. 
   The multiple queues  202  provide parallel processing of transmission jobs. Each of the multiple queues may correspond to an index that is being updated or created. Different indexes can be created for different data repositories, such as for different servers in the data repositories  102 . As another example, when a data repository includes knowledge entities of different languages, there may be created a separate index for each language. Thus, a transmission job may relate to more than one index. 
   An optimizer  203  scans the multiple queues  202  selects tasks that are at the front of their respective queues. Each of the tasks corresponds to a data transmission that is to be performed by executing batch jobs, and the optimizer will determine control parameters to be individually assigned to the batch jobs. The control parameters will determine whether the system during transmission should change the data amount identified by at least one of the batch jobs. 
   Determining the control parameters may involve the optimizer  203  performing an optimization operation. That is, the optimizer may calculate which control parameters to assign to the batch jobs so that the transmission is most efficient under current system characteristics. A system characteristic taken into account may include a priority of one or more of the batch jobs. For example, the batch job may be under a deadline to be performed by a predefined time. A system characteristic taken into account may include a constraint on the transmission. For example, there may be a limit on the maximum number of batch jobs to be performed, a maximum system load, and combinations of such constraints. A system characteristic taken into account may include a volume of the data to be transmitted. 
   The optimization operation may involve using a mathematical model to solve a constraint optimization problem. Essentially, the optimizer  203  may retrieve or otherwise receive information about the characteristics of the transmission, such as how much information is to be transmitted from what source to what recipient and when, including priorities and other constraints. Then, the optimizer, which may be provided with predefined algorithms or other mathematical tools, attempts to find a solution to the question of how to best organize the transmission job. Examples of the specifics that can be included in the solution are: the maximum number of subjobs; a maximum number of subjobs into which certain batch jobs can be divided; a maximum number of subjob levels into which certain batch jobs can be divided; and a threshold for initiating a change in the respective batch job. The optimizer can use standard tools, such as a numerical analysis library, in solving the constraint optimization problem. During transmission, the optimizer  203  can evaluate, based on measured system performance, whether there is another solution to the constraint optimization problem and assign new control parameters to one or more of the batch jobs. 
   A job manager  204  initiates the respective tasks. Upon selecting a task, the job manager creates batch jobs with the respective individually assigned control parameters determined by the optimizer  203  including, for example, the size of a data amount to be processed by each of the subjobs. Finally, the job manager initiates batch job processing  206  wherein the batch job(s) will be performed. 
   An example of the batch job processing  206  will be described with reference also to  FIG. 3 , which schematically shows batch jobs  300 . The job manager  204  creates a first batch job  302  that corresponds to the entire transmission job and the first batch job is split into four subjobs, here first batch subjobs  306 . A control parameter is individually assigned to each of the first batch subjobs. The splitting action changes the data amount directly handled by the first batch job by reducing it to zero. In contrast, each of the batch subjobs that are currently being performed identifies a portion of the first batch job&#39;s data amount. The system may log a time stamp upon initiating each of the first batch subjobs. Such a time stamp can be used in determining whether batch (sub)jobs are being promptly processed. 
   While processing the batch jobs, the system monitors a system performance parameter. If the parameter does not meet the predefined standard, the system may access the control parameter of at least one of the batch jobs to determine whether to make any changes. The system may then automatically change the data amount identified by at least one of the first batch subjobs  306  in accordance with its respective control parameter. For example, if the processing is less efficient than the predefined standard calls for, the system may seek to increase the number of batch jobs. 
   Here, the system splits one of the first subjobs  306  into three new subjobs. That is, the data amount identified by the one of the first subjobs  306  is divided among second batch subjobs  308 . These subjobs will continue to be processed as are the remaining ones of the first batch subjobs  306 . Accordingly, the system continues with retrieving the data identified by the subjobs from the data repository. The optimizer  203  assigns control parameter individually to the second batch subjobs. If the performance parameter does not meet the predefined standard, the system may change the data amount identified by any of the batch jobs in accordance with its control parameter. 
   Here, the system splits one of the second batch subjobs  308  into third batch subjobs  310 , and thereafter again determines that the performance parameter does not meet the predefined standard. Upon accessing control parameter(s) to determine whether to change any data amount(s), the system can either perform a merge  312  of the third subjobs or a split  314  of another of the second batch subjobs. 
   The system may record events that occur during the transmission and that relate to the batch jobs. Such events can include the above described actions in the processing  206 , including the detection of one or more instances where the performance parameter does not meet the predefined standard. Also, system status and performance measures may be recorded. For example, events can be recorded in a job log  208 . The optimizer  203  may access the job log in determining the control parameters for the batch jobs. 
     FIG. 4  is a flow chart of a method  400  that can be performed in organizing a transmission of repository data. The method  400  may be performed in the system  100 . For example, a computer program product may include instructions that cause a processor to perform operations comprising the steps of the method  400 . As shown in  FIG. 4 , the method  400  includes the following steps: 
   Receiving, in a computer system, a request to transmit data from a data repository to a data recipient. The data is to be transmitted by executing batch jobs that each identify a data amount to be transmitted to the data recipient. For example, the system  100  may receive a transmission request from a user or through an automatic scheduling. The request may involve transmitting data from the repository  102  to the indexing service  104  for creating or updating one or more indices for the search engines  106 . 
   Assigning, in step  420 , control parameters individually to each of the batch jobs. For example, the intelligent indexing system  110  may be available for performing batch jobs using the concurrent indexing engine  114  that, in turn, may include the job manager  204  creating a batch job that is divided into subjobs in the batch job processing  206 . The optimizer  203  may solve a constraint optimization problem to determine how to organize the transmission. The solution may specify the number of batch jobs to be used and the control parameters for each of them. 
   Upon detecting during transmission that a performance parameter of the computer system does not meet a predefined standard, automatically changing, in step  430 , the data amount identified by at least one of the batch jobs in accordance with the control parameter assigned to the at least one of the batch jobs. For example, at least one of first subjobs  306  may be split into the second subjobs  308 . As another example, the system may merge third subjobs  310 . 
     FIG. 5  is a block diagram of a computer system  500  that can be used in the operations described above, according to one embodiment. For example, one or more systems  500  may be included in the system  100 . 
   The system  500  includes a processor  510 , a memory  520 , a storage device  530  and an input/output device  540 . Each of the components  510 ,  520 ,  530  and  540  are interconnected using a system bus  550 . The processor  510  is capable of processing instructions for execution within the system  500 . In one embodiment, the processor  510  is a single-threaded processor. In another embodiment, the processor  510  is a multi-threaded processor. The processor  510  is capable of processing instructions stored in the memory  520  or on the storage device  530  to display graphical information for a user interface on the input/output device  540 . 
   The memory  520  stores information within the system  500 . In one embodiment, the memory  520  is a computer-readable medium. In one embodiment, the memory  520  is a volatile memory unit. In another embodiment, the memory  520  is a non-volatile memory unit. 
   The storage device  530  is capable of providing mass storage for the system  500 . In one embodiment, the storage device  530  is a computer-readable medium. In various different embodiments, the storage device  530  may be a floppy disk device, a hard disk device, an optical disk device, or a tape device. 
   The input/output device  540  provides input/output operations for the system  500 . In one embodiment, the input/output device  540  includes a keyboard and/or pointing device. In one embodiment, the input/output device  540  includes a display unit for displaying graphical user interfaces. 
   The invention can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Apparatus of the invention can be implemented in a computer program product tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by a programmable processor; and method steps of the invention can be performed by a programmable processor executing a program of instructions to perform functions of the invention by operating on input data and generating output. The invention can be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. A computer program is a set of instructions that can be used, directly or indirectly, in a computer to perform a certain activity or bring about a certain result. A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. 
   Suitable processors for the execution of a program of instructions include, by way of example, both general and special purpose microprocessors, and the sole processor or one of multiple processors of any kind of computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memories for storing instructions and data. Generally, a computer will also include, or be operatively coupled to communicate with, one or more mass storage devices for storing data files; such devices include magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and optical disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits). 
   To provide for interaction with a user, the invention can be implemented on a computer having a display device such as a CRT (cathode ray tube) or LCD (liquid crystal display) monitor for displaying information to the user and a keyboard and a pointing device such as a mouse or a trackball by which the user can provide input to the computer. 
   The invention can be implemented in a computer system that includes a back-end component, such as a data server, or that includes a middleware component, such as an application server or an Internet server, or that includes a front-end component, such as a client computer having a graphical user interface or an Internet browser, or any combination of them. The components of the system can be connected by any form or medium of digital data communication such as a communication network. Examples of communication networks include, e.g., a LAN, a WAN, and the computers and networks forming the Internet. 
   The computer system can include clients and servers. A client and server are generally remote from each other and typically interact through a network, such as the described one. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. 
   A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.