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version 1.1.2.17, 2013/12/16 18:31:08 version 1.4, 2014/11/13 13:29:21
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         Using the CIM/XML Pull Operations          Using the CIM/XML Pull Operations and FQL query Language
  
 STATUS  Date: 12 November 2014
   
 <<< The TODO section is being maintained during the review and checkin process  
 to keep track of problems, errors, notes, etc.  Must be deleted before  
 checkin to head of tree. Please feel free to add notes, etc in this  
 section as you review/test.>>>>>>  
   
 TODO list:  
    1. Binary operation from OOP.  Need to add counter to binary  
       protocol to be able to count objects in response. Generates  
       warnings in things like messageserializer and does not work with  
       OOP right now.  Corrected by converting to XML.  
    2. OpenExecQuery - Code is incorrect in that it does not include the  
       return from the exec query function to the aggregator yet.  
    3. Code for Pull part of OpenQueryInstancesRequest a) should be part of  
       the common CIMOperationRequestDispatcher execCommon code.  
    4. The changes to WQLCIMOperationRequestDispatcher and CQL... for handling  
       pull not completed so we feed the responses back to the EnmerationContext  
       queues  
    3. Lots of minor TODOs, diagnostics, etc.  
    4. External runtime variables. Proposing that they be fixed for this release  
       rather than set by configuration.  This should be discussed.  Am making  
       this a separate bug.  See bug 9819 for the changes to cover this.  
    5. Decision on EnumerationContext timeout (separate thread or just  
       checks during other operations). Can we, in fact really keep the  
       enumeration context table and queue under control without monitoring  
       with a separate thread. We must monitor for:  
       a. Client operation that stop requesting (i.e. inter operation time  
           exceeds operationTimeout). Note that if it simply exceeds the time  
           the next operation does the cleanup.  The issue is those clients that  
           simply stop and do not either close or go to completion.  
       b. We should protect against providers that no not every finish delivering  
           or take to long between deliveries.  This does not exist in Pegasus  
           today  
    6. Consider moving some of the code in dispatcher from templates to common  
       functions which would mean adding intermediate classes in CIMMessage but  
       would reduce code size.  
    7. Extension to avoid double move of objects in CIMResponseData (one  
       into enumerationContext queue and second to new cimResponseData for  
       response.  Want to avoid second move by extending Open/Pull response  
       messages to include count and CIMResponse data to count objects out  
       of queue when converting (avoids the second move).  Big issue here  
       with binary data since need to extend format to count it.  
    8. NEXT TASKS:  
       a. test the enumeration timeout thread  
       b. finish and test the OpenQueryInstances  
       c. Clean up TODOs  
       d. Find issue when we run makepoststarttests in pullop client with  
          forceProviderProcesses = true.  This causes an operation like  
          cimcli pei CIM_ManagedElement to not complete (client timeout)  
          sometimes.  
   
 15 December 2013  
 1. Mergeout and mergein up to 15 December 2013  
 2. Clean up issues from tests documented in bug 9676 last week.  
 3. Clean up some code in dispatcher  
 4. Remove the filter function from ResponseStressc++Provider.  
   
 21 November 2013  
 1. Mergeout from head of tree to 21 November 2013.  
   
 18 November 2013  
 1. Cleanup of a bunch of minor errors and completion of all of the code for  
    the openQueryInstances except for the PullInstances in Dispatcher and  
    the aggregator function.  
 2. OpenqueryInstances added to cimcli.  
   
 13 October 2013 CVS branch update.  
 1. Integrated bug 9786 into the branch.  Note that we need to test the  
    generated statistics.  
 2. Mergeout executed to update to head of tree as of 8:00 am 13 October 2013.  
 3. Cleaned up several errors in OOP processing.  Note that there is at least  
    one issue left when we to a pull on ManagedElement in at least one of the  
    namespaces.  
 4. Cleaned up some of the outstanding diagnostic code  
 5. Generally passes all tests except for one test of pullop where it is trying  
    to pull enum instances CIM_ManagedElement from a particular namespace.  
   
 NOTE: I did not make comments here for changes in October despite the fact  
 that I did 2 mergouts, number of fixes, and a mergein.  
   
 30 September 2013 - CVS Update  
 Mergeout head of tree up to 29 September 2013.  
   
 29 September 2013. CVS update.  
 1. Modified calls to statisticalData.cpp to a) directly call with request  
    type, b) incorporate the open, pull, etc. messages.  However, since these  
    are not part of the CIM class, we must do something special with them.  
    See bug 9785 for full solution to this issue.  
 2. Corrected OOP interface to enable new flag to indicate internal operations  
    and set host, etc.  
 3. Add code to CQLOperationsDispatcher and WQLOperationDispatcher to clean  
    up CIMResponseDataCounter after filtering.  
 4. Modified ProviderAgent to set Host info for some pull operations.  
 5. Added new flag to CIMBinMsgSerializer and Deserializer.  
   
 17 September 2013 CVS update (Actually two different updates over 3 days)  
 1. Clean up some issues in CIMMessage.h and CIMMessage.cpp  
 2. Extend OpenExecQuery to WQL and CQL processors but return not complete  
 3. Remove memory leak in EnumerationContext and EnumerationContextTable  
    handling.  
 4. Created template functions for much of the pull operations.  
 5. Reversed order of queryLanguage and query (and changed names to match  
    execQuery) in client and server.  Note that these are the execQuery  
    WQL and CQL filters and NOT FQL filters.  
 6. Some code cleanup in dispatcher  
 7. Today, passes all tests in pullop but issue in alltests. For some reason  
    not finding CIMObjectManager instance. Also, leaves enumeration contexts  
    if client terminates since cleanup thread not operating.  
 8. XML from OOP not correctly processed.  
   
 14 September 2013 CVS update  
 Merged out up to 25 August.  Cleaned up all operations and standardized code.  
 At this point the non pull operations code is in a set of templates but the  
 pull is not yet.  
 Fixed a significant number of problems so that it appears that the operations  
 except for OpenExecQuery run stably, at least with the pullop test program.  
 Note that there is a problem in that the Interop control provider is not  
 returning its singleton wbemserver object for some reason.  Causes a test  
 failure  
   
 Fixed for 16 June CVS Update  
    1. Cleaned up the enumerationContext and Table release functions and tested  
       to confirm that we do not lose memory in either normal sequences or  
       sequences that close early. Cleaned up pullop and added more tests  
 Taged Before: PREAUG25UPDATE and after POSTAUG25UPDATE  
   
 Fixed for 9 June CVS update  
    1. Cleaned up code for OpenQueryInstances.  Note that this is incomplete.  
       No support in WQL or CQL Operations  
    2.  
   
 What was fixed for 5 June checkin.  
    1. Extended ResponseTest MOF for for both CMPI and C++ subclasses  
    2. Fixed issues with pullop.  
    3. Fixed temp issue with CIMResponseData size by putting in mutex. That  
       is not a permanent fix but it gets around issue probably in the control  
       of the move logic that meant counts were off.  
    4. Fixed issues in Dispatcher so that associator code works. Still messy  
       code in the dispatcher.  
    5. Changed name of Enumerationtable.h & cpp to EnumerationContextTable.*  
    6  Changed name of ResponseStressTest module, classes, etc.  
   
 TAG: TASK_PEP317_5JUNE_2013_2  
   
 2 June 2013  
   
 Issues  - KS  
   
  - Still way to many TODO and KS comments and KS_TEMPS.  Removing bit by bit.  
   
  - Runtime variable connection for the config parameters not installed. That  
    has been made into a separate bug (see bug 9819)  
   
 5. Issue with the threaded timer.  For some reason during tests it  
 eventually calls the timer thread with trash for the parm (which is  
 pointer to the EnumerationTable object). Caught because we do a valid  
 test at beginning of the function.  
   
 6. Still using the templates in CIMOperationRequestDispatcher to simplify  
 the handle... processing.  
   
 7. I think I have a way around the double move of objects in the  
 EnumerationContext so that the outputter will just take a defined number  
 of objects directly from the gathering cache and save the second move.  
   
 8. Not yet passing all tests but getting closer now. The major test that is  
 causing an error today is the execution of a full enumeration with the  
 forceProviders = true.  This causes a client timeout sometimes.  
  
   STATUS
  
   The client pull operations and FQL query language are incorporated into
   OpenPegasus 2.14. consistent and compatible with the DMTF specifications for
   the pull operations (DMTF DSP0200 v 1.4, and DMTF DSP0212 v 1.01.
   This readme defines the characteristics, limitations,
   etc. for that implementation.
  
 =========================================== ===========================================
   
 OVERVIEW: OVERVIEW:
  
 The operation extensions for pull operations defined in the DMTF specification The operation extensions for pull operations defined in the DMTF specification
 DSP0200 V 1.4 were implemented in Pegasus effective Pegasus version 2.11  DSP0200 V 1.4 were implemented in OpenPegasus effective version 2.14
 including Client and Server. including Client and Server.
  
 These operations extend the CIM/XML  individual operations to operation These operations extend the CIM/XML  individual operations to operation
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 The following new CIM/XML operations as defined in DSP0200 are included; The following new CIM/XML operations as defined in DSP0200 are included;
  
     -OpenEnumerateInstances      -openEnumerateInstances
     -openEnumerateInstancePaths     -openEnumerateInstancePaths
     -OpenReferenceInstances      -openReferenceInstances
     -OpenReferenceInstancePaths      -openReferenceInstancePaths
     -OpenAssociatiorInstances      -openAssociatiorInstances
     -OpenAssociatorInstancePaths      -openAssociatorInstancePaths
     -OpenQueryInstances      -openQueryInstances
     -PullInstancesWithPath      -pullInstancesWithPath
     -PullInstancePaths      -pullInstancePaths
     -PullInstances      -pullInstances
     -CloseEnumeration      -closeEnumeration
     -EnumerationCount      -enumerationCount (deprecated by DMTF and incomplete)
      OpenExecQuery  
   
 The following  operations have not been implemented in this version of Pegasus:  
   
     -OpenQueryInstances  
   
 The following limitations on the implementation exist;  
   
 1. The filterQueryLanguage and filterQuery parameters are processed by  
    the Pegasus client but the server returns error if there is any data in  
    either parameter. This work does not include the development of the  
    query language.  Note that a separate effort to extend Pegasus to use  
    the DMTF FQL query language is in process.  
   
 2. The input parameter continueOnError is processed correctly by the client  
    but the Pegasus server only provides for false since the server does not  
    include logic to continue processing responses after an error is  
    encountered.  
    This is consistent with the statement in the specification that use of  
    this functionality is optional and the fact that the DMTF agrees that all  
    of the issues of continuing after errors have not been clarified.  
   
 3. The operation enumerationCount is not processed by the server today since  
    a) really getting the count would be the same cost as the corresponding  
    enumeration, b) the server does not include a history or estimating  
    mechanism for this to date.  
    NOTE: After a through review as part of the development of the next version  
    of CMPI we have concluded that this operation is probably not worth the  
    effort.  Since it is optional, Pegasus will only return the unknown status  
    at this point  
  
 Since the concept of sequences of operations linked together (open, pull, close) Since the concept of sequences of operations linked together (open, pull, close)
 is a major extension to the original CIM/XML operation concept of completely is a major extension to the original CIM/XML operation concept of completely
 independent operations several new pieces of functionality are implemented independent operations several new pieces of functionality are implemented
 to control interOperationTimeouts, counts of objects to be returned, etc.  to control interOperation timeouts, counts of objects to be returned, etc.
  
 TBD - Review this  NOTE: More detailed information on the pull operations is contained in:
   1. The OpenPegasus wiki (pull operations work group)
   2. The pull operations PEP (preliminary today)
   3. Presentations in the OpenPegasus wiki, in particular in the
      pull operations workgroup documentation at:
  
 CLIENT  https://wiki.opengroup.org/pegasus-wiki/doku.php?id=dev:workgroups:pulloperationsupportworkgroup:pull_operation_support_work_group
   
   
   OPENPEGASUS CLIENT
  
 The new operations follow the same pattern as the APIs for existing operations The new operations follow the same pattern as the APIs for existing operations
 in that: in that:
  
 1. All errors are handled as CIMException and Exception  1. All errors are handled as CIMException and Exception the same as the
      original client operations.  Note, however, that there are additional
      CIMStatusCodes for the new operations.
  
 2. The means of inputting parameters are the same except that there are 2. The means of inputting parameters are the same except that there are
    significantly more input parameters with the open operations and for the    significantly more input parameters with the open operations and for the
    first time operations return parameters as well as objects in the    first time operations return parameters as well as objects in the
    response.  Specifically the open and pull operations return values for    response.  Specifically the open and pull operations return values for
    enumerationContext which is the identity for a pull sequence and     the enumerationContext argument which is the identity for a pull sequence and
    endOfSequence which is the marker the server sends in open and pull     the endOfSequence argument which is the marker the server sends in open and
    responses when it has no more objects to send.     pull responses when it has no more objects to send.
   
 The significant differences include:  The significant differences between the open... and original enumerate,
   associator, and reference operations includes:
 1. Processing of parameters on responses (i.e. the endOfSequence and  
    enumerationContext parameters are returned for open and pull operations).  1. The new pull client operations typically require multiple client operations
      to retrieve a complete set of data (ex. openEnumerateInstances and
      pullInstancesWithPath) are equivalent to the old enumerateInstances
      client request.  While the whole collection of responses might be returned
      on the open if the maxObjectCount argument is set larger than the the number
      of objects in the total response, depending on the speed of delivery of
      objects from providers, the response might still not deliver everything
      in the initial response.  The client code writer should always assume that
      multiple requests will be required.
   
   2. Processing of parameters on responses (i.e. the endOfSequence and
      enumerationContext arguments are returned for open and pull operations)
      These return arguments are used to control the loop retrieving data
      for an enumeration sequence (ex. the sequence of OpenEnumerateInstances
      and PullInstancesWithPath that represents a complete enumeration
      sequence). The sequence continues until the server responds with
      EndOfSequence is true, and the enumerationContext is the identifier
      for the sequence.
  
 2. Numeric arguments (Uint32 and Uint64 include the option of NULL in some  3. Numeric arguments (Uint32 and Uint64) include the option of NULL in some
    cases so they are packaged inside classes Uint32Arg and Uint64Arg in the    cases so they are packaged inside classes Uint32Arg and Uint64Arg in the
    client api.     client API.
  
 3. The association and reference operations ONLY process instances.  They do  4. The openAsociatorInstances and openReferenceInstances operations ONLY
    not include the capability to return classes like reference and associator     process instances.  They do not include the capability to return classes
    do and therefore return CIMInstance rather than CIMObject.     as reference and associator requests do and therefore return CIMInstance
      rather than CIMObject.
  
 4. Paths are returned in all cases (i.e OpenEnumerateInstances and  5. Paths are returned for the instance operations as part of the returned
    PullInstancesWithPath where they were not with EnumeratInstances.     instances (ex. openEnumerateInstances and pullInstancesWithPath) where
      they were not with EnumerateInstances.
  
 5. The client must maintain state between operations in a sequence (using  6. The client must maintain state between operations in an enumeration
    the enumerationContext parameter).     sequence (using the enumerationContext parameter returned with open
      and pull responses). The client must always return the last
      enumerationContext received as the server may modify the
      enumerationContext for each response in an enumeration sequence.
  
 TBD- Are there more differences.  The client API is defined in the header file:
  
       pegasus/src/Pegasus/Client/CIMCLient.h
  
 SERVER  
  
 The Pegasus server attempts to always deliver the requested number of objects  OPENPEGASUS SERVER
 for any open or pull request (the specification allows for the server to  
 deliver less than the requested number of objects and specifically to return  
 zero objects on open).  We felt that it was worth any extra cost in processing  
 to provide the client with exactly what it had requested.  
  
 The pegasus server always closes an enumeration sequence upon receipt of any  The OpenPegasus server attempts to always deliver at least some objects
   in a response.  It does not wait to deliver the exact number requested but
   waits to deliver at least some. The sever will wait about 15 seconds to
   deliver and if there is nothing delivered from the providers it will then
   return a response with zero objects in it so that the client does not
   timeout.  This would only occur if the providers are extremely slow (i.e.
   greater than 15 seconds) in preparing response objects to be delivered.
   
   The OpenPegasus server always closes an enumeration sequence upon receipt of any
 error from the providers, repository, etc. Therefore the server will reject error from the providers, repository, etc. Therefore the server will reject
 any request that has continueOnError = true;  any request that has the continueOnError argument = true;
  
 Expansion to allow the continue on error may be added in a future version. Expansion to allow the continue on error may be added in a future version.
 In any case, the whole purpose of the continue on error is really to allow In any case, the whole purpose of the continue on error is really to allow
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 future to support the continueOnError other than possibly allowing the provider future to support the continueOnError other than possibly allowing the provider
 to continue processing after it has received an error. to continue processing after it has received an error.
  
 PROVIDERS  OPENPEGASUS PROVIDERS
  
 This implementation requires NO changes to the existing providers.  The  This implementation (OpenPegasus version 2.14) requires NO changes to the
 provider APIs operate just as they do with the original operations.  existing providers.  The provider APIs operate just as they do with the
   original operations.
  
 Because the server processing is different however, there may be some Because the server processing is different however, there may be some
 behavior differences primarily because the client now controls the speed of behavior differences primarily because the client now controls the speed of
 delivery of objects. delivery of objects.
  
 In previous versions of Pegasus, the server attempts to deliver objects as  In previous versions of Pegasus, the server attempted to deliver objects as
 rapidly as then can be put on the network.  In the case of HTTP chunked requests rapidly as then can be put on the network.  In the case of HTTP chunked requests
 they are delivered in chunks of about 100 objects. The primary delay for the they are delivered in chunks of about 100 objects. The primary delay for the
 providers was the processing of each segment through the server.  The server providers was the processing of each segment through the server.  The server
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 and then delivered as one non-chunked response. There were no delays for the and then delivered as one non-chunked response. There were no delays for the
 providers, just lots of possible memory use in the server. providers, just lots of possible memory use in the server.
  
 The responses from providers (delivered through the deliver(...) interface are  The responses from providers (delivered through the deliver(...) interface) are
 gathered into segments of about 100 objects and this group of objects is moved gathered into segments of about 100 objects and this group of objects is moved
 through the server to be delivered to the client. through the server to be delivered to the client.
  
 However with the inclusion of the pull operations,   The segments of objects  However with the inclusion of the pull operations, the segments (CIMResponseData
 from the providers are cached in the server response path until the  objects containing the instance or path objects) from the providers are cached
 maxObjectCount for that request (open or pull) and that number returned in a  in the server response cache until the next pull request and that number
 non-chunked response. Thus, if the client is slow to issue pull requests,  is returned in the response to that pull. Thus, if the client is slow to issue
 the providers might be delayed at some point to reduce memory usage in the  pull requests, the providers might be delayed at some point to reduce memory
 server (the delay appears as slow response tothe deliver operation).  usage in the server (the delay appears as slow response to the deliver operation).
  
 In other words, the time to process large sets of responses from the provider In other words, the time to process large sets of responses from the provider
 now depends on the speed of handling the client. now depends on the speed of handling the client.
  
 It is important to remember in developing providers that the Pegasus server  It is important to remember in developing providers that the OpenPegasus server
 can most efficiently process responses if they are passed from the provider can most efficiently process responses if they are passed from the provider
 to the server individually or in small arrays of objects rather than the to the server individually or in small arrays of objects rather than the
 provider gathering very large arrays of objects and sending them to the provider gathering very large arrays of objects and sending them to the
 server. server.
  
 NEXT GENERATION PROVIDERS  FQL (FILTER QUERY LANGUAGE)
 KS_TODO  
   The FQL implementation is complete in accord with the DMTF
   specification DSP 0212 except for a few issues including:
   
   1. The regex for the LIKE operation is the same as CQL basic. It provides
      only the following special characters   "." and  "*".
   2. The implementation does not include the comparison of
      embeddedInstances functionality.
   3. The implementation does not include the handling of Uint8[] as
      strings.
   4. Since the cimserver provides the filtering, it can only filter properties
      that are returned from the providers.  Therefore all of the properties in
      the filter MUST BE included in any property list provided with the request.
   
   For more details on the FQL implementation see the readme.txt in the
       directory pegasus/src/Pegasus/FQL.
   
   OpenPegasus will remove these limitations in a future version.
   
   The FQL implementation includes a large set of sample queries in the
   directory:
   
       pegasus/src/Pegasus/FQL/tests/Parser
   
   including both good and error generating queries.
   
   ==================================================================
   LIMITATIONS IN OPENPEGASUS 2.14
   
   1. The openQueryInstances does not allow requesting the class on response
      (i.e. the returnQueryResultClass argument must be false in this version).
      Since OpenPegasus is actively proposing that this argument be deprecated
      we will see what happens in future releases.
   
   2. The openEnumerateInstanceNames, openAssociatorNames, and openReferenceNames
      do not allow use of the query filter.  This is because:
      a. The intention is to deprecate these operations completely and remove
         them in a future versionof both the specificatons and OpenPegasus.
      b. They require that the server call the providers with the corresponding
         enumerate, associators, references to get the full instances to
         filter and then remap this to the corresponding Names operation.
         We propose that if the user wants just the paths, this can be achieved
         with the instances operation with the propertylist set empty which
         requests that the server return no properties.
   
   3. The filterQuery filtering is done by the server, not the providers in this
      version of OpenPegasus. This will be modified in a future version of
      OpenPegasus when the provider API extensions for the pull operations
      have been resolved.  Version 2.1 of the CMPI specification will resolve
      this issue.  However, this has imposed another limitation as mentioned above,
      the properties that are part of the filter MUST BE included in any
      propertyList in the request.  OpenPegasus does not check to be sure that
      all properties in the filter are also in the request and would therefore
      try to filter the response on non-existent properties.
   
   4. The input parameter continueOnError is processed correctly by the client
      but the Pegasus server only provides code for 'false' value, since the server
      does not include logic to continue processing responses after an error is
      encountered.
      This is consistent with the statement in the specification that use of
      this functionality is optional and the fact that the DMTF agrees that all
      of the issues of continuing after errors have not been clarified.
   
   5. The operation enumerationCount is not processed by the server today since
      a) Getting the count would be the same cost as the corresponding
      enumeration, b) the server does not include a history or estimating
      mechanism for this to date.
      NOTE: After a through review as part of the development of the next version
      of CMPI we have concluded that this operation is probably not worth the
      effort.  Since it is optional, Pegasus will only return the unknown status
      at this point. Further it is the intention of the DMTF to deprecate this
      function.
  
 CONFIGURATION PARAMETERS  ===================================================================
   PULL OPERATION CONFIGURATION PARAMETERS
  
 The server includes several configuration parameters to set limits on the The server includes several configuration parameters to set limits on the
 processing of pull operations.  All of these configuration parameters are  processing of pull operations.
 compile time parameters rather than runtime.  
  
 1. Maximum value of minimum interoperation time.  This parameter defines the  RUNTIME CONFIGURATION PARAMETERS
 maximum time allowed between the return of an open or pull response and  
 the receipt of the next pull or a close operation before the server may  1. Maximum value of interoperation time (pullOperationsMaxTimeout) -
 close the enumeration.  The specification allows the server to set a  This parameter defines the maximum time allowed between the return of an open
 maximum interoperation time and refuse open requests that with requested  or pull response and the receipt of the next pull or a close operation before
 operationTimeout greater than that time.  the server may close the enumeration.
 CIM_ERR_INVALID_OPERATION_TIMEOUT  The specification allows the server to set a maximum interoperation time and
   refuse open requests that with requested operationTimeout greater than that
 This value is set with the Pegasus environment variable  time.
 PEGASUS_PULL....  
   2. Maximum number of objects returned in a single open or pull operation
 2. Maximum objects returned in a single open or pull operation.  The server  (pullOperationsMaxObjectCount) - The server can set a maximum limit on the
 can set a maximum limit on the number of objects that can be returned in  number of objects that can be returned in a single open or pull operation
 a single open or pull oepration with the maxObjectCount parameter.  with the maxObjectCount parameter. This parameter sets the maximum limit.
   The absolute maximum allowed without recompiling (and changing a value in
 3. Whether the server allows 0 as an interoperation timeout value. The value  Common/Constants.h) is 10000.
 zero is s special value for the interoperationTimeout in that it tells the  
 server to not timeout any enumeration sequence.  3. Default operationTimeout (pullOperationsdefaultTimeout) - If the client
   does not specify an operation timeout in the open request, the server uses
   the value defined by this runtime configuration variable.  The default
   is 30 seconds.
   
   STATISTICS
   
   The server does maintain some statistics on the pull operations and outputs
   these to the console when the server is shutdown.  In this version there
   is no way to output these statistics other than to the console and at
   shutdown.
   
   COMPILE TIME CONFIGURATION PARAMETERS
   
   1. Whether the server allows 0 as an interoperation timeout value - The value
   zero is a special value for the interoperationTimeout in that it tells the
   server to not timeout the enumeration sequence. This should never be used
   as it allows a client to open enumeration sequences that will not be
   cleaned up if the client does not properly terminate them.  There is a
   compile time variable in CIMOperationRequestDispatcher that would allow this
   to be set so 0 interoperation is allowed but we recommend that it never
   be used since it removes a significant component of the server management
   of enumerationContext information.
  
 With this value for interoperationTimeout, the only way to close an With this value for interoperationTimeout, the only way to close an
 enumeration sequence is to complete all of the pulls or issue the close. enumeration sequence is to complete all of the pulls or issue the close.
 If for some reason the sequence is not completed, that enumeration context If for some reason the sequence is not completed, that enumeration context
 would remain open indefinitly.  Since in Pegasus any open enumeration  would remain open indefinitely.  Since in Pegasus any open enumeration
 context uses resources (the context object and any provider resposnes that  context uses resources (the context object and any provider responses that
 have not yet been issued in a response) it would appear that most have not yet been issued in a response) it would appear that most
 platforms would not want to allow the existence of enumeration contexts platforms would not want to allow the existence of enumeration contexts
 that cannot be closed by the server. that cannot be closed by the server.
  
 4, maximum consecutive pull requests with 0 maxObjectCount.  The use of the  2. Maximum consecutive pull requests with 0 maxObjectCount - The use of the
 pull operation with maxObjectCount set to zero could be used to keep an pull operation with maxObjectCount set to zero could be used to keep an
 enumeration context open indefinitly (this tells the server to restart the  enumeration context open indefinitely (this tells the server to restart the
 interoperationTimeout but not send any objects in the response). Therefore the interoperationTimeout but not send any objects in the response). Therefore the
 specification allows for the server setting maximum limits on this behavior specification allows for the server setting maximum limits on this behavior
 and returning the error CIM_ERR_SERVER_LIMITS_EXCEEDED if this limit is and returning the error CIM_ERR_SERVER_LIMITS_EXCEEDED if this limit is
 exceeded. exceeded.
   
 Note that this is maximum CONSECUTIVE pulls so that issuing a pull with Note that this is maximum CONSECUTIVE pulls so that issuing a pull with
 a non-zero count resets this counter. a non-zero count resets this counter.
  
 KS-TBD - Is this really logical since we can still block by just issuing  Pegasus sets the value of this limit to 1000 and allows the implementer to
 lots of zero request and an occansional request for one object.  modify it by compiling  with the PEGASUS_MAXIMUM_ZERO_OBJECTCOUNT define  in
   CIMOperationRequestDispatcher.cpp modified.
 Pegaus sets the value of this limit to 1000 and allows the implementer to  
 modify it with the PEGASUS_MAXIMUM_ZERO_OBJECTCOUNT environment variable.  3. Time to wait for next response from providers - In the case where providers
   are responding very slowly, the goal is to generate responses with
 5. Default operationTimeout -  zero instances at regular intervals to allow the client to keep the
   enumeration context alive.  This wait time is set by a compile time define
 The default of this parameter is to refuse operat  (PEGASUS_PULL_MAX_OPERATION_WAIT_SEC)in pegasus/src/Pegasus/Common/Constants.h
   and is set to 15 seconds in the current release.
 In the current release of Pegasus these are all compile time parameters.  
   4. Time to wait before killing off an enumeration context that is blocked
   by missing provider responses. In the rare case where providers do not complete
 NOTES On working with task branch.  their responses to the server there is a compile-time counter that trys to
   clean up the providers and finally just kill the enumeration sequence after
 Merge out Process  a defined number of consecutive pulls that return zero objects.
   The limit is defined in pegasus/src/Pegasus/Constants.h
   
   NOTE: The development team is trying to consolidate all such constants and
   #define definitions that control overall server characteristics but are not
   runtime parameters in Constants.h
   
   ===================================================================
   TESTING PULL OPERATIONS
   
   The pull operations are tested primarily with two client programs in the
   directory Pegasus/Client/tests
   
   1. pullop and it corresponding Makefile provide extensive tests of the
      pull operations and comparison of the results with the corresponding non
      pull operations.
   
   2. PullErrors  tests a number of error scenarios with the pull operations.
   
   3. cimcli has been extended to allow execution of the pull operations with new
      operations that parallel the existing operations:
      enumerateinstances(ei) - corresponding is pullenumerateInstances(pei)
      ni -> pni   enumerateInstanceNames
      r -> pr     references
      rn -> prn   referenceNames
      a  -> pa    associators
      ar -> par   associatorNames
  
    To keep our TASK branch in sync with the current head of tree we need     These execute complete pull sequences (open, pull) with cimcli options
    to do a regular merge out.  the TaskMakefile contains the makefile     to control parameters like maxObjectCount, interoperation Timeout, etc.
    procedures to do this efficiently.  NOTE: Following these procedures is  
    important in that you are merging out new material each time you do  
    the merge out.  If you were just to repeatedly merge out, you would be  
    merging previously merged changes a second time causing a real mess.  
  
     Start with new directory and put TaskMakefile above pegasus (needed so you  
     have this file for the initial operations.  
  
       make -f TaskMakefile branch_merge_out BNAME=PEP317-pullop  ## takes a long time  =============================================================
   TODO LIST - Post 2.14 release
    This checks out current head, merges it into task branch and sets tags     1. Binary operation from OOP.  Need to add counter to binary
    for the mergeout.  Note that at the end of this step this work is        protocol to be able to count objects in response. Generates
    part of the TASK... branch.        warnings in things like messageserializer and does not work with
         OOP right now.  Fixed by converting to XML. Concluded that we do not
    NOW check for conflicts, errors, etc. that resulted from the merge.        need to do this. The binary response is not really used often
    Look for conflict flags, compare the results (I use linux merge as a        in the current environment So double mapping it is not a major issue.
    good graphic compare tool) and build and test. When you are satisfied        Leave this as FUTURE
    that the merge out is clean, you can commit the results to the TASK...     2. Minor TODOs, diagnostics, etc. still in the code. Reduced almost to
    branch        none now.  We are leaving some in as PEGASUS_DEBUG
      3. Extension to avoid double move of objects in CIMResponseData (one
    To commit the work to  this into Task branch        into enumerationContext queue and second to new CIMResponseData for
         response.  Want to avoid second move by extending open/pull response
       make -f mak/TaskMakefile branch_merge_out_commit BNAME=PEP317-pullop        messages to include count and CIMResponse data to count objects out
         of queue when converting (avoids the second move). This would mean
   or manually commit and finish as follows        extending the output writers to allow the count field to be supplied
         so they would only create output for up to the count supplied.(Make
     cvs commit        this future beyond bug 9676). This is fairly extensive because it
     make -f mak/TaskMakefile  branch_merge_out_finish BNAME=PEP317-pullop        extends beyond CIMResponseData to SCMO and XML writers where the
         XmlWriters used by encodeXmlResponse would have to have counters
 ## This last step is important since it cleans up temporary tags to prepare        added. Then instead of copying on getCache we would simply pass the
    you for the next checkout        cache and count on and the writer would take and remove.
      4. Add more static tests (currently only OpenEnumerateInstances and
 COMPARE TASKBRANCH WITH HEAD        OpenEnumerateInstanceNames covered).
      5. Correct issue between operations and HTTP where we are sending
     In a new pegasus work space do same as above for merge out.        trailers with exceptions. Modify response mechanisms so that we
         set non-chunked for all responses where we send error responses to
     make -f TaskMakefile BNAME=PEP317-pullop        avoid the trailers. NOTE: There should be now a bug on this in general
         where we would want to send an initial error without the trailer. Should
     This produces a result which is all of the head merged into the branch.        have always done that.
     A diff of this is all the new changes to the head of tree that you will     6. It would be more efficient in dispatcher to always use exception for
     include into the merge.         rejects and change the _reject functions so that they never return
          when they reject. This is VERY LOW PRIORITY and primarily saves
          a few lines of code in the reject functions and their calls.  Means we
          would code.
          _rejectIfEnumerationToBroad(...);
          _rejectIfThisParameterIncorrect(...);
   
          instead of
          if (_rejectIfEnum...)
          {
              return true
          }
          It would mean that the method trace for the handlers would not return
          an exit if we rejected. VERY LOW PRIORITY. Possibly FUTURE. No behavior
          change, just more compact source code but it messes with the method
          trace logic.
       7. There are still a couple of template functions around the task of
          distributing requests to the multiple providers.
          In fact there are two similar but different templates for
          the associators(i.e. assoc, ref, etc.) functions and the parallel
          openAssoc functions.  It would be nice to consolidate that logic and
          further to try to create a non-template form for those functions. LOW
          PRIORITY
       8. Trace functions in CIMResponseData,h & cpp should be PEGASUS_DEBUG.
          Same for trace function in EnumerationContext and
          EnumerationContextTable
       9. Question. We added trace in CIMRequestOperationDispatcher.cpp if
          query enum is recevied with no object path.  However, since this is
          a provider problem should we be doing something other than a trace
          (ex. log) since traces are often not really used and they do generate
          lots of data whereby something like this could get lost. Also, need
          to review what level of trace if we keep trace.
      10. Better statistics keeping for open, etc. through cimperf.
      11. Incorporate a simple test of pull operations into the TestClient
      12. Define a simpler iteration interface for the client so that
          the client does not have to directly control the open, pull, etc.
          operations.
      13. Map properties in the FQL Filter to properties in any property list
          provided.
      14. Output statistical information on a regular basis rather than just
          as server shutdown and to the log or somewhere else than just the
          console.
  


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