Awesome, thank you! Best regards,
Shaofeng Shi 史少锋 Apache Kylin PMC Email: [email protected] Apache Kylin FAQ: https://kylin.apache.org/docs/gettingstarted/faq.html Join Kylin user mail group: [email protected] Join Kylin dev mail group: [email protected] liang <[email protected]> 于2019年12月10日周二 下午6:23写道： > Hi ShaoFeng, > > I'll create an issue in JIRA later. Thanks for your reply. > > Regards, > Liang > > On Tue, Dec 10, 2019 at 6:17 PM ShaoFeng Shi <[email protected]> > wrote: > >> Yes, Kylin supports in parallel segment building. It seems to be a bug >> introduced in KYLIN-3977 in Kylin 2.6.3. Would you like to create it as a >> JIRA so that you can get notified when there is a hot-fix? The JIRA can be >> reported in https://issues.apache.org/jira/secure/Dashboard.jspa , and >> selecting KYLIN as the project. Thank you! >> >> >> Best regards, >> >> Shaofeng Shi 史少锋 >> Apache Kylin PMC >> Email: [email protected] >> >> Apache Kylin FAQ: https://kylin.apache.org/docs/gettingstarted/faq.html >> Join Kylin user mail group: [email protected] >> Join Kylin dev mail group: [email protected] >> >> >> >> >> liang <[email protected]> 于2019年12月10日周二 下午5:43写道： >> >>> Hi there, >>> We noticed a segment refresh job at ERROR status at "*2019-12-10 >>> 02:27:15*". After a deep dive into kylin.log, we found that the >>> WriteConflictException was raised when trying to update the last modified >>> time for the dict. >>> >>> (Sensitive content are consered) >>> >>> 2019-12-10 02:27:15,576 ERROR [Scheduler 1186524190 Job >>>> f76fb12e-477f-b404-e021-adaf520d04bb-321] common.HadoopShellExecutable:65 : >>>> error execute >>>> HadoopShellExecutable{id=f76fb12e-477f-b404-e021-adaf520d04bb-03, >>>> name=Build Dimension Dictionary, state=RUNNING} >>>> org.apache.kylin.common.persistence.WriteConflictException: Overwriting >>>> conflict >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict, >>>> expect old TS 1575916011421, but it is 1575916035573 >>>> at >>>> org.apache.kylin.storage.hbase.HBaseResourceStore.updateTimestampImpl(HBaseResourceStore.java:372) >>>> at >>>> org.apache.kylin.common.persistence.ResourceStore.lambda$updateTimestampWithRetry$4(ResourceStore.java:443) >>>> at >>>> org.apache.kylin.common.persistence.ExponentialBackoffRetry.doWithRetry(ExponentialBackoffRetry.java:52) >>>> at >>>> org.apache.kylin.common.persistence.ResourceStore.updateTimestampWithRetry(ResourceStore.java:442) >>>> at >>>> org.apache.kylin.common.persistence.ResourceStore.updateTimestampCheckPoint(ResourceStore.java:437) >>>> at >>>> org.apache.kylin.common.persistence.ResourceStore.updateTimestamp(ResourceStore.java:432) >>>> at >>>> org.apache.kylin.dict.DictionaryManager.updateExistingDictLastModifiedTime(DictionaryManager.java:197) >>>> at >>>> org.apache.kylin.dict.DictionaryManager.trySaveNewDict(DictionaryManager.java:157) >>>> at >>>> org.apache.kylin.dict.DictionaryManager.saveDictionary(DictionaryManager.java:339) >>>> at >>>> org.apache.kylin.cube.CubeManager$DictionaryAssist.saveDictionary(CubeManager.java:1145) >>>> at >>>> org.apache.kylin.cube.CubeManager.saveDictionary(CubeManager.java:1107) >>>> at >>>> org.apache.kylin.cube.cli.DictionaryGeneratorCLI.processSegment(DictionaryGeneratorCLI.java:100) >>>> at >>>> org.apache.kylin.cube.cli.DictionaryGeneratorCLI.processSegment(DictionaryGeneratorCLI.java:69) >>>> at >>>> org.apache.kylin.engine.mr.steps.CreateDictionaryJob.run(CreateDictionaryJob.java:73) >>>> at org.apache.kylin.engine.mr.MRUtil.runMRJob(MRUtil.java:93) >>>> at >>>> org.apache.kylin.engine.mr.common.HadoopShellExecutable.doWork(HadoopShellExecutable.java:63) >>>> at >>>> org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:167) >>>> at >>>> org.apache.kylin.job.execution.DefaultChainedExecutable.doWork(DefaultChainedExecutable.java:71) >>>> at >>>> org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:167) >>>> at >>>> org.apache.kylin.job.impl.threadpool.DefaultScheduler$JobRunner.run(DefaultScheduler.java:114) >>>> at >>>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) >>>> at >>>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) >>>> at java.lang.Thread.run(Thread.java:745) >>>> >>> >>> We have a glance at the codebase (Kylin-2.6.4), we found the last >>> modified time of the dict (which has been built) will be updated at the >>> step "Build Dimension Dictionary". The log blow shows the same dict is >>> processed many times. >>> >>> Liangs-MacBook-Pro:~ pwrliang$ cat 12-10.log |grep "has already been >>>> built, save it"|grep "THIS_IS_COLUMN_NAME" >>>> 2019-12-10 02:07:10,103 DEBUG [Scheduler 1186524190 Job >>>> 5c4b2ee9-c8aa-9a69-ffb0-3a6811ad22a9-372] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:07:11,036 DEBUG [Scheduler 1186524190 Job >>>> 593979b8-e80b-590f-335b-526c2fc49080-295] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:07:20,455 DEBUG [Scheduler 1186524190 Job >>>> 160952f3-fef2-4fdf-c08a-77d49f830805-246] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:07:20,888 DEBUG [Scheduler 1186524190 Job >>>> 69304c1c-cc02-3bbe-67d4-efdd3858e88a-234] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:07:21,634 DEBUG [Scheduler 1186524190 Job >>>> 345b688c-7992-f2cf-ae06-835675f545ea-117] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:07:23,040 DEBUG [Scheduler 1186524190 Job >>>> 0ea711ed-71b5-ae47-a34a-f0a27fd9d7cc-303] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:07:36,358 DEBUG [Scheduler 1186524190 Job >>>> 6daf351f-5073-128f-8754-f499e345db54-308] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:26:43,716 DEBUG [Scheduler 1186524190 Job >>>> c90a765c-976f-49c2-38d8-e6812d091cfb-295] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:26:44,944 DEBUG [Scheduler 1186524190 Job >>>> cd108004-12c6-078f-8646-f29841de9e40-205] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:26:51,306 DEBUG [Scheduler 1186524190 Job >>>> d808dadf-8eea-34db-1b1f-d50e923b4e3a-372] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:27:15,523 DEBUG [Scheduler 1186524190 Job >>>> ea07ef8f-b2b7-b3f8-c481-df615025217d-117] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:27:15,535 DEBUG [Scheduler 1186524190 Job >>>> f76fb12e-477f-b404-e021-adaf520d04bb-321] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> 2019-12-10 02:29:42,504 DEBUG [Scheduler 1186524190 Job >>>> f894f427-b170-19b6-76fb-e1b671659771-321] cli.DictionaryGeneratorCLI:99 : >>>> Dict for 'THIS_IS_COLUMN_NAME' has already been built, save it >>>> >>> >>> Since we issue the refresh segments request concurrently (with REST >>> APIs), the dict has a chance to be modified concurrently. Kylin uses >>> checkAndPut >>> to update HBase to prevent race-condition, so the >>> WriteConflictException may be raised when updating the same resource. >>> >>> Liangs-MacBook-Pro:~ pwrliang$ cat 12-10.log |grep >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict|grep >>>> "Update dictionary " >>>> 2019-12-10 02:07:10,223 INFO [Scheduler 1186524190 Job >>>> 5c4b2ee9-c8aa-9a69-ffb0-3a6811ad22a9-372] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575914830203 >>>> 2019-12-10 02:07:11,109 INFO [Scheduler 1186524190 Job >>>> 593979b8-e80b-590f-335b-526c2fc49080-295] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575914831090 >>>> 2019-12-10 02:07:20,554 INFO [Scheduler 1186524190 Job >>>> 160952f3-fef2-4fdf-c08a-77d49f830805-246] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575914840528 >>>> 2019-12-10 02:07:21,762 INFO [Scheduler 1186524190 Job >>>> 345b688c-7992-f2cf-ae06-835675f545ea-117] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575914841727 >>>> 2019-12-10 02:07:23,253 INFO [Scheduler 1186524190 Job >>>> 0ea711ed-71b5-ae47-a34a-f0a27fd9d7cc-303] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575914843095 >>>> 2019-12-10 02:26:43,843 INFO [Scheduler 1186524190 Job >>>> c90a765c-976f-49c2-38d8-e6812d091cfb-295] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575916003771 >>>> 2019-12-10 02:26:51,436 INFO [Scheduler 1186524190 Job >>>> d808dadf-8eea-34db-1b1f-d50e923b4e3a-372] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575916011421 >>>> 2019-12-10 02:27:15,593 INFO [Scheduler 1186524190 Job >>>> ea07ef8f-b2b7-b3f8-c481-df615025217d-117] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575916035573 >>>> 2019-12-10 02:29:42,564 INFO [Scheduler 1186524190 Job >>>> f894f427-b170-19b6-76fb-e1b671659771-321] dict.DictionaryManager:198 : >>>> Update dictionary >>>> /dict/THIS_IS_CUBE_NAME/THIS_IS_COLUMN_NAME/010dbf72-52a9-e759-08a7-ed7cde0c6e0d.dict >>>> lastModifiedTime to 1575916182549 >>>> >>> >>> The log above shown that the job "f76fb12e-477f-b404-e021-adaf520d04bb" >>> has not been print out the log - "Update dictionary blablabla...." >>> because of the WriteConflictException. >>> >>> The question is: refreshing segments concurrently is supported for Kylin >>> 2.6.4? Concurrently refreshing is very important for us, since we want to >>> reduce the building time. >>> >>> Regards, >>> Liang >>> >>
