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1 karl 1.1.2.1 Using the CIM/XML Pull Operations 2 3 STATUS 4
5 karl 1.1.2.4 <<< The TODO section is being maintained during the review and checkin process
6 karl 1.1.2.1 to keep track of problems, errors, notes, etc. Must be deleted before 7 checkin to head of tree. Please feel free to add notes, etc in this 8 section as you review/test.>>>>>> 9
10 karl 1.1.2.5 NOTES On working with task branch. 11
12 karl 1.1.2.6 Merge out Process
13 karl 1.1.2.5
14 karl 1.1.2.6 To keep our TASK branch in sync with the current head of tree we need 15 to do a regular merge out. the TaskMakefile contains the makefile 16 procedures to do this efficiently. NOTE: Following these procedures is 17 important in that you are merging out new material each time you do 18 the merge out. If you were just to repeatedly merge out, you would be 19 merging previously merged changes a second time causing a real mess. 20 21 Start with new directory and put TaskMakefile above pegasus (needed so you 22 have this file for the initial operations. 23 24 make -f TaskMakefile branch_merge_out BNAME=PEP317-pullop ## takes a long time 25 26 This checks out current head, merges it into task branch and sets tags 27 for the mergeout. Note that at the end of this step this work is 28 part of the TASK... branch. 29 30 NOW check for conflicts, errors, etc. that resulted from the merge. 31 Look for conflict flags, compare the results (I use linux merge as a 32 good graphic compare tool) and build and test. When you are satisfied 33 that the merge out is clean, you can commit the results to the TASK... 34 branch
35 karl 1.1.2.5
36 karl 1.1.2.6 To commit the work to this into Task branch
37 karl 1.1.2.5
38 karl 1.1.2.6 make -f mak/TaskMakefile branch_merge_out_commit BNAME=PEP317-pullop
39 karl 1.1.2.5 40 or manually commit and finish as follows 41
42 karl 1.1.2.6 cvs commit 43 make -f mak/TaskMakefile branch_merge_out_finish BNAME=PEP317-pullop
44 karl 1.1.2.5
45 karl 1.1.2.6 ## This last step is important since it cleans up temporary tags to prepare 46 you for the next checkout
47 karl 1.1.2.5 48 COMPARE TASKBRANCH WITH HEAD 49
50 karl 1.1.2.7 In a new pegasus work space do same as above for merge out.
51 karl 1.1.2.5
52 karl 1.1.2.7 make -f TaskMakefile BNAME=PEP317-pullop
53 karl 1.1.2.5
54 karl 1.1.2.7 This produces a result which is all of the head merged into the branch. 55 A diff of this is all the new changes to the head of tree that you will 56 include into the merge.
57 karl 1.1.2.5
58 karl 1.1.2.3
59 karl 1.1.2.4 TODO list:
60 karl 1.1.2.3 1. Binary operation from OOP. Need to add counter to binary 61 protocol to be able to count objects in response. Generates 62 warnings in things like messageserializer and does not work with 63 OOP right now.
64 karl 1.1.2.4 2. OpenExecQuery - Code is incorrect in that it used InstancesWithPath 65 where the spec is instances with no path. Need new function to wrap 66 getInstanceElement(withoutPathElement) in XmlReader. Note that 67 Alternate is to put flag on InstancesWith Path to say no path 68 3. Code for Pull part of OpenQueryInstancesRequest a) should be part of 69 the common CIMOperationRequestDispatcher execCommon code. 70 4. The changes to WQLCIMOperationRequestDispatcher and CQL... for handling 71 pull not completed so we feed the responses back to the EnmerationContext 72 queues
73 karl 1.1.2.7 3. Lots of minor TODOs, diagnostics, etc.
74 karl 1.1.2.4 4. External runtime variables. Decide this as part of PEP. The variables 75 exist in CIMOperationRequestDispatcher but not in CIMConfig. The primary 76 ones to consider are: 77 a. System maxObjectCount. Setting some maximum size on what a pull 78 client can request (i.e. the maximum size of the maxObjectCount on 79 Open... and pull operations. 80 b. Pull interoperationTimeout (max times between operations). This is 81 the maximum number of seconds on the operationTimeout parameter of the 82 Open operations 83 c. Maximum size of the responseCache before it starts backing up 84 responses to the providers.
85 karl 1.1.2.3 5. Decision on EnumerationContext timeout (separate thread or just
86 karl 1.1.2.4 checks during other operations). Can we, in fact really keep the 87 enumeration context table and queue under control without monitoring 88 with a separate thread. We must monitor for: 89 a. Client operation that stop requesting (i.e. inter operation time 90 exceeds operationTimeout). Note that if it simply exceeds the time 91 the next operation does the cleanup. The issue is those clients that 92 simply stop and do not either close or go to completion. 93 b. We should protect against providers that no not every finish delivering 94 or take to long between deliveries. This does not exist in Pegasus 95 today
96 karl 1.1.2.8 6. Clean up code in Dispatcher. Want to at least reduce the code for the 97 Open Operations to a set of templates so we know that the code is the 98 same for all operations. Right now the existing operations enum, assoc, 99 etc. are all in templates but not the open operations. Note that the 100 pull is a single template for both pullInstances and pullInstancePaths. 101 However, we might be able to reduce this to a single function by adding 102 a new level to CIMMessage.h (CommonPullResponse)
103 karl 1.1.2.3 7. Extension to avoid double move of objects in CIMResponseData (one 104 into enumerationContext queue and second to new cimResponseData for 105 response. Want to avoid second move by extending Open/Pull response 106 messages to include count and CIMResponse data to count objects out 107 of queue when converting (avoids the second move). Big issue here 108 with binary data since need to extend format to count it.
109 karl 1.1.2.8 8. NEXT TASKS: 110 a. get the pull operations rather than a template into a single 111 function by creating a new CIMPullResponse message in CIMMessage.h that 112 contains the pull data. Then we can use a single function to process all 113 pull operations. 114 b. test the timeout thread 115 c. New Mergout to bring up to to date again. 116 d. Fix known problem with the interop provider. 117 118 14 September 2013 CVS update 119 Merged out up to 25 August. Cleaned up all operations and standardized code. 120 At this point the non pull operations code is in a set of templates but the 121 pull is not yet. 122 Fixed a significant number of problems so that it appears that the operations 123 except for OpenExecQuery run stably, at least with the pullop test program. 124 Note that there is a problem in that the Interop control provider is not 125 returning its singleton wbemserver object for some reason. Causes a test 126 failure
127 karl 1.1.2.7 128 Fixed for 16 June CVS Update 129 1. Cleaned up the enumerationContext and Table release functions and tested 130 to confirm that we do not lose memory in either normal sequences or 131 sequences that close early. Cleaned up pullop and added more tests
132 karl 1.1.2.8 Taged Before: PREAUG25UPDATE and after POSTAUG25UPDATE
133 karl 1.1.2.4 134 Fixed for 9 June CVS update 135 1. Cleaned up code for OpenQueryInstances. Note that this is incomplete. 136 No support in WQL or CQL Operations 137 2. 138 139 What was fixed for 5 June checkin.
140 karl 1.1.2.3 1. Extended ResponseTest MOF for for both CMPI and C++ subclasses 141 2. Fixed issues with pullop. 142 3. Fixed temp issue with CIMResponseData size by putting in mutex. That 143 is not a permanent fix but it gets around issue probably in the control 144 of the move logic that meant counts were off. 145 4. Fixed issues in Dispatcher so that associator code works. Still messy 146 code in the dispatcher. 147 5. Changed name of Enumerationtable.h & cpp to EnumerationContextTable.* 148 6 Changed name of ResponseStressTest module, classes, etc. 149 150 TAG: TASK_PEP317_5JUNE_2013_2 151
152 karl 1.1.2.2 2 June 2013
153 karl 1.1.2.1 154 Issues - KS 155 1. have not installed the binary move in CIMResponseData. Please run 156 with OPP off. 157 2. Some problem in the processing so we are getting server crashes. 158 Right no I am guessing that this is in the binaryCodec and am going to 159 expand the test tools to allow testing through the localhost. 160 161 3. Still way to many TODO and KS comments and KS_TEMPS. Removing bit by bit. 162 163 4. Env variable connection for the config parameters not installed. 164 165 5. Issue with the threaded timer. For some reason during tests it 166 eventually calls the timer thread with trash for the parm (which is 167 pointer to the EnumerationTable object). Caught because we do a valid 168 test at beginning of the function. 169
170 karl 1.1.2.2 6. Still using the templates in CIMOperationRequestDispatcher to simplify 171 the handle... processing. 172 173 7. I think I have a way around the double move of objects in the 174 EnumerationContext so that the outputter will just take a defined number 175 of objects directly from the gathering cache and save the second move. 176 177 8. Not yet passing all tests but getting closer now. 178 179 9. Created a tag before this commit TASK_PEP317_1JUNE_2013. 180 181 10. Next Tag will be TASK_PEP317_2_JUNE_2013 in the task branch 182 183
184 karl 1.1.2.1 =========================================== 185 186 OVERVIEW: 187 188 The operation extensions for pull operations defined in the DMTF specification 189 DSP0200 V 1.4 were implemented in Pegasus effective Pegasus version 2.11 190 including Client and Server. 191 192 These operations extend the CIM/XML individual operations to operation 193 sequences where the server must maintain state between operations in a 194 sequence and the client must execute multiple operations to get the full 195 set of instances or instance paths. 196 197 The following new CIM/XML operations as defined in DSP0200 are included; 198 199 -OpenEnumerateInstances 200 -openEnumerateInstancePaths 201 -OpenReferenceInstances 202 -OpenReferenceInstancePaths 203 -OpenAssociatiorInstances 204 -OpenAssociatorInstancePaths 205 karl 1.1.2.1 -PullInstancesWithPath 206 -PullInstancePaths 207 -CloseEnumeration 208 -EnumerationCount
209 karl 1.1.2.2 OpenExecQuery
210 karl 1.1.2.1 211 The following operations have not been implemented in this version of Pegasus: 212 213 -OpenQueryInstances 214 215 The following limitations on the implementation exist; 216 217 1. The filterQueryLanguage and filterQuery parameters are processed by 218 the Pegasus client but the server returns error if there is any data in
219 karl 1.1.2.2 either parameter. This work does not include the development of the 220 query language. Note that a separate effort to extend Pegasus to use 221 the DMTF FQL query language is in process.
222 karl 1.1.2.1 223 2. The input parameter continueOnError is processed correctly by the client 224 but the Pegasus server only provides for false since the server does not 225 include logic to continue processing responses after an error is 226 encountered. 227 This is consistent with the statement in the specification that use of 228 this functionality is optional and the fact that the DMTF agrees that all 229 of the issues of continuing after errors have not been clarified. 230 231 3. The operation enumerationCount is not processed by the server today since 232 a) really getting the count would be the same cost as the corresponding 233 enumeration, b) the server does not include a history or estimating 234 mechanism for this to date.
235 karl 1.1.2.2 NOTE: After a through review as part of the development of the next version 236 of CMPI we have concluded that this operation is probably not worth the 237 effort. Since it is optional, Pegasus will only return the unknown status 238 at this point
239 karl 1.1.2.1 240 Since the concept of sequences of operations linked together (open, pull, close) 241 is a major extension to the original CIM/XML operation concept of completely 242 independent operations several new pieces of functionality are implemented 243 to control interOperationTimeouts, counts of objects to be returned, etc. 244 245 TBD - Review this 246 247 CLIENT 248 249 The new operations follow the same pattern as the APIs for existing operations 250 in that: 251 252 1. All errors are handled as CIMException and Exception 253 254 2. The means of inputting parameters are the same except that there are 255 significantly more input parameters with the open operations and for the 256 first time operations return parameters as well as objects in the 257 response. Specifically the open and pull operations return values for 258 enumerationContext which is the identity for a pull sequence and 259 endOfSequence which is the marker the server sends in open and pull 260 karl 1.1.2.1 responses when it has no more objects to send. 261 262 The significant differences include: 263 264 1. Processing of parameters on responses (i.e. the endOfSequence and 265 enumerationContext parameters are returned for open and pull operations). 266 267 2. Numeric arguments (Uint32 and Uint64 include the option of NULL in some 268 cases so they are packaged inside classes Uint32Arg and Uint64Arg in the 269 client api. 270 271 3. The association and reference operations ONLY process instances. They do 272 not include the capability to return classes like reference and associator 273 do and therefore return CIMInstance rather than CIMObject. 274 275 4. Paths are returned in all cases (i.e OpenEnumerateInstances and 276 PullInstancesWithPath where they were not with EnumeratInstances. 277 278 5. The client must maintain state between operations in a sequence (using 279 the enumerationContext parameter). 280 281 karl 1.1.2.1 TBD- Are there more differences. 282 283 284 SERVER 285 286 The Pegasus server attempts to always deliver the requested number of objects 287 for any open or pull request (the specification allows for the server to 288 deliver less than the requested number of objects and specifically to return 289 zero objects on open). We felt that it was worth any extra cost in processing 290 to provide the client with exactly what it had requested. 291 292 The pegasus server always closes an enumeration sequence upon receipt of any 293 error from the providers, repository, etc. Therefore the server will reject
294 karl 1.1.2.2 any request that has continueOnError = true; 295 296 Expansion to allow the continue on error may be added in a future version. 297 In any case, the whole purpose of the continue on error is really to allow 298 input from good providers to be mixed with providers that return errors so 299 that generally this would mean simply changing the logic in the return mechanism 300 to not shutdown when an error is received from any given provider. 301 302 Generally we do not believe that the providers need to do much more in the 303 future to support the continueOnError other than possibly allowing the provider 304 to continue processing after it has received an error.
305 karl 1.1.2.1 306 PROVIDERS 307 308 This implementation requires NO changes to the existing providers. The 309 provider APIs operate just as they do with the original operations. 310 311 Because the server processing is different however, there may be some 312 behavior differences primarily because the client now controls the speed of 313 delivery of objects. 314 315 In previous versions of Pegasus, the server attempts to deliver objects as 316 rapidly as then can be put on the network. In the case of HTTP chunked requests 317 they are delivered in chunks of about 100 objects. The primary delay for the 318 providers was the processing of each segment through the server. The server 319 is blocked so that no other segment can proceed through the server until that 320 segment is processed and sent on the network. 321 In the case of non-chunkedresponses, they are completely gathered in the serve 322 and then delivered as one non-chunked response. There were no delays for the 323 providers, just lots of possible memory use in the server. 324 325 The responses from providers (delivered through the deliver(...) interface are 326 karl 1.1.2.1 gathered into segments of about 100 objects and this group of objects is moved 327 through the server to be delivered to the client. 328 329 However with the inclusion of the pull operations, The segments of objects 330 from the providers are cached in the server response path until the 331 maxObjectCount for that request (open or pull) and that number returned in a 332 non-chunked response. Thus, if the client is slow to issue pull requests, 333 the providers might be delayed at some point to reduce memory usage in the 334 server (the delay appears as slow response tothe deliver operation). 335 336 In other words, the time to process large sets of responses from the provider 337 now depends on the speed of handling the client. 338 339 It is important to remember in developing providers that the Pegasus server 340 can most efficiently process responses if they are passed from the provider 341 to the server individually or in small arrays of objects rather than the 342 provider gathering very large arrays of objects and sending them to the 343 server. 344
345 karl 1.1.2.2 NEXT GENERATION PROVIDERS 346 KS_TODO 347
348 karl 1.1.2.1 CONFIGURATION PARAMETERS 349 350 The server includes several configuration parameters to set limits on the 351 processing of pull operations. All of these configuration parameters are 352 compile time parameters rather than runtime. 353 354 1. Maximum value of minimum interoperation time. This parameter defines the 355 maximum time allowed between the return of an open or pull response and 356 the receipt of the next pull or a close operation before the server may 357 close the enumeration. The specification allows the server to set a 358 maximum interoperation time and refuse open requests that with requested 359 operationTimeout greater than that time. 360 CIM_ERR_INVALID_OPERATION_TIMEOUT 361 362 This value is set with the Pegasus environment variable 363 PEGASUS_PULL.... 364 365 2. Maximum objects returned in a single open or pull operation. The server 366 can set a maximum limit on the number of objects that can be returned in 367 a single open or pull oepration with the maxObjectCount parameter. 368 369 karl 1.1.2.1 3. Whether the server allows 0 as an interoperation timeout value. The value 370 zero is s special value for the interoperationTimeout in that it tells the 371 server to not timeout any enumeration sequence. 372 373 With this value for interoperationTimeout, the only way to close an 374 enumeration sequence is to complete all of the pulls or issue the close. 375 If for some reason the sequence is not completed, that enumeration context 376 would remain open indefinitly. Since in Pegasus any open enumeration 377 context uses resources (the context object and any provider resposnes that 378 have not yet been issued in a response) it would appear that most 379 platforms would not want to allow the existence of enumeration contexts 380 that cannot be closed by the server. 381 382 4, maximum consecutive pull requests with 0 maxObjectCount. The use of the 383 pull operation with maxObjectCount set to zero could be used to keep an 384 enumeration context open indefinitly (this tells the server to restart the 385 interoperationTimeout but not send any objects in the response). Therefore the 386 specification allows for the server setting maximum limits on this behavior 387 and returning the error CIM_ERR_SERVER_LIMITS_EXCEEDED if this limit is 388 exceeded. 389 Note that this is maximum CONSECUTIVE pulls so that issuing a pull with 390 karl 1.1.2.1 a non-zero count resets this counter. 391 392 KS-TBD - Is this really logical since we can still block by just issuing 393 lots of zero request and an occansional request for one object. 394 395 Pegaus sets the value of this limit to 1000 and allows the implementer to 396 modify it with the PEGASUS_MAXIMUM_ZERO_OBJECTCOUNT environment variable. 397 398 5. Default operationTimeout - 399 400 The default of this parameter is to refuse operat 401 402 In the current release of Pegasus these are all compile time parameters.

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