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Stefan-1807 avatar image
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Stefan-1807 asked LukasYu-msft commented

Process data only randomly fails

Hi,

I have an environment running SSAS 2019 (Tabular onprem) .

We are using the Tabular Object Model (TOM) library executing processing commands (multiple times per day).
This is done by first executing a Process data only (only on some partitions of tables) followed by a process calculate.

This usually works fine, but sometimes (maybe ones per 30 attempt) it fails with the following exception:

Microsoft.AnalysisServices.Tabular.TomInternalException: An internal error has occured.
at Microsoft.AnalysisServices.Tabular.Model.MergeAffectedSubtree(MetadataObject affectedSubtreeRoot, CopyContext mergeCopyContext)
at Microsoft.AnalysisServices.Tabular.Model.HandleImpactAffectedObjects(ServerImpact impact)
at Microsoft.AnalysisServices.Tabular.Model.ApplyImpact(ServerImpact impact)
at Microsoft.AnalysisServices.Tabular.ExecuteUtil.TryExecuteXmla(Model model, String xmlaRequest, XmlaResultCollection& xmlaResults)
at Microsoft.AnalysisServices.Tabular.Model.SaveChangesImpl(SaveOptions options)

Nothing is written in the msmdsrv.log file.

I have xevents running, catching ProgressReportEnd events (to be able to monitor performance).
Here I can see that it logs EventSubClass 58 (Sequence point Finished sequence point algorithm) just before ending, but that is also logged when the command finish with success.

It think that this is at the end of the process data only. I know that it has not started with Process calculate.

Any suggestions on what can be wrong or how to monitor it even further to find the cause?

Best Regards
Stefan

sql-server-analysis-services
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1 Answer

LukasYu-msft avatar image
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LukasYu-msft answered LukasYu-msft commented

If it is randomly failing, I would suggest you to use sql server profile to trace the SSAS server, see which query or what event causes this crashing.

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Hi @LukasYu-msft

Thank you for your answer.
Can you be a bit more specific, what events should I track?
Using xEvents, today I log all ProgressReportEnd events to an SQL table.



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Hi Stefan,
Since the give error info is not very sufficient.
You could try to use the Profiler to log the database activity, see if any abnormaly occurs during the process.

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