Solved: High CPU utilization with Thread method Prep/Index...

After upgrading my HANA to Revision 96, I have noticed a high CPU utilization because of Thread method "Prep/Indexing". Below are the details of the Thread type & method

Service: preprocessor

Hierarchy:

Connection ID: -1

Thread ID: 127571

Thread Type: Request

Thread Method: prep/indexing

Thread Detail: TEXT/_SYS_REPO:ACTIVE_OBJECTen.CDATA:69353

Duration (ms): 2482122

As these number of threads are increasing, the CPU is getting utilized more. I'd like to know more about what goes on here. Any information available anywhere? what does thread method "prep/indexing" means ? Can i reduce the CPU utilization ?

Regards,

Pavan Gunda

SAP Managed Tags:
SAP HANA

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Accepted Solutions (1)

Please find the below reply

This can be reduced by suspending the queue for the responsible table.

ALTER FULLTEXT INDEX _SYS_REPO.FTI_ACTIVE_OBJECT_CDATA SUSPEND QUEUE;

and restart the responsible service.

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Answers (1)

This thread method is linked to indexing of fulltext indexes. In fact there is a fulltext index defined on column CDATA of table ACTIVE_OBJECT. Is always the same table shown? Then you may have an individual problem with this table for some reason. Can you create a call stack of one of the hanging thread? Does it work in inxight::word_stemming_implementation::stem_terms_with_common_next?

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Hi Martin,

Yes, it is the same table shown always. I have generated a call stack. Please find my current situation in the system.

There are totally 25 threads running with same situation.

Below is the first thread.

Service: preprocessor

Hierarchy:

Connection ID: -1

Thread ID: 139211

Calling:

Caller: 141493@ukgfsdbdh001:30303

Thread Type: Request

Thread Method: prep/indexing

Thread Detail: TEXT/_SYS_REPO:ACTIVE_OBJECTen.CDATA:69353

Duration (ms): 1569894

PS:: I am not able to find the caller thread 141493

call stack for Thread ID: 139211 :

1 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::NormalizationBuffer::trimTrailingPendingChars()+0x20 at NormalizationBuffer.cpp:366 (libtadatstructureanalyzer.so)

2 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::NormalizationBuffer::addChar(unsigned short)+0x154 at NormalizationBuffer.cpp:287 (libtadatstructureanalyzer.so)

3 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::XMLTextParser::insertBlankLine()+0x10 at XMLTextParser.cpp:172 (libtadatstructureanalyzer.so)

4 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::XMLTextParser::endElement(SAP::TextAnalysis::Strings::UString const&, int)+0x2a at XMLTextParser.cpp:154 (libtadatstructureanalyzer.so)

5 : SAP::TextAnalysis::XMLParser::XMLParserImpl::endElement(unsigned short const*)+0x52 at XMLParserImpl.cpp:427 (libtadatutilities.so)

6 : xercesc_3_1::SAXParser::startElement(xercesc_3_1::XMLElementDecl const&, unsigned int, unsigned short const*, xercesc_3_1::RefVectorOf<xercesc_3_1::XMLAttr> const&, unsigned long, bool, bool)+0x230 at XMLElementDecl.hpp:500 (libxerces-c-3.1.so)

7 : xercesc_3_1::IGXMLScanner::scanStartTag(bool&)+0xb63 at IGXMLScanner.cpp:2098 (libxerces-c-3.1.so)

8 : xercesc_3_1::IGXMLScanner::scanContent()+0x1c0 at IGXMLScanner.cpp:892 (libxerces-c-3.1.so)

9 : xercesc_3_1::IGXMLScanner::scanDocument(xercesc_3_1::InputSource const&)+0x94 at IGXMLScanner.cpp:217 (libxerces-c-3.1.so)

10 : xercesc_3_1::SAXParser::parse(xercesc_3_1::InputSource const&)+0x96 at SAXParser.cpp:575 (libxerces-c-3.1.so)

11 : SAP::TextAnalysis::XMLParser::XMLParserImpl::parse(SAP::TextAnalysis::Strings::UString const&, SAP::TextAnalysis::Strings::UString const&, bool)+0x1ea at XMLParserImpl.cpp:204 (libtadatutilities.so)

12 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::XMLTextParser::process(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Annotation>, int&)+0xa3 at XMLTextParser.cpp:52 (libtadatstructureanalyzer.so)

13 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::XMLDetagger::process(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Annotation>, int&)+0x154 at XMLDetagger.cpp:148 (libtadatstructureanalyzer.so)

14 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::StructureAnalyzer::StructureAnalyzerImpl::analyze(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Document>)+0xc63 at StructureAnalyzerImpl.cpp:160 (libtadatstructureanalyzer.so)

15 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::StructureAnalyzer::analyze(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Document>)+0x21 at StructureAnalyzer.cpp:93 (libtadatstructureanalyzer.so)

16 : preprocessor::TextAnalysisController::analyze(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Document> const&, ltt::map<ltt::basic_string<char, ltt::char_traits<char> >, ltt::basic_string<char, ltt::char_traits<char> >, ltt::less<ltt::basic_s

17 : preprocessor::PreprocessorImpl::tasdkActivity(unsigned int, TRexCommonObjects::SingleCell&, TRexCommonObjects::SingleColumn const&, preprocessor::ConfigParameters const&, unsigned short, ltt::basic_string<char, ltt::char_traits<char> > const&, bool) const+

18 : preprocessor::PreprocessorImpl::process(unsigned int, unsigned int const&, TRexCommonObjects::SingleCell&, TRexCommonObjects::SingleColumn const&, preprocessor::ConfigParameters const&, int&, TrexService::HandlerContext&, ltt::basic_string<char, ltt::char_

19 : preprocessor::Preprocessor::dispatch(unsigned int, unsigned short, int&, TRexCommonObjects::DocumentContainer&, TrexService::HandlerContext&, ltt_adp::vector<ltt::tuple<unsigned int, unsigned int, int, ltt::null_type, ltt::null_type, ltt::null_type, ltt::n

20 : preprocessor::Preprocessor::handleIndexing(unsigned int, unsigned short, int&, TRexCommonObjects::DocumentContainer&, TrexService::HandlerContext&, ltt_adp::vector<ltt::tuple<unsigned int, unsigned int, int, ltt::null_type, ltt::null_type, ltt::null_type,

21 : preprocessor::Preprocessor::handle(TrexNet::Request&, TrexService::HandlerContext&)+0x2e4 at Preprocessor.cpp:392 (hdbpreprocessor)

22 : TrexService::WorkerThread::run(void*)+0x6c0 at TrexServiceThreads.cpp:546 (libhdbbasement.so)

23 : TrexThreads::PoolThread::run()+0x968 at PoolThread.cpp:274 (libhdbbasement.so)

24 : TrexThreads::PoolThread::run(void*&)+0x10 at PoolThread.cpp:124 (libhdbbasement.so)

25 : Execution::Thread::staticMainImp(void**)+0x875 at Thread.cpp:496 (libhdbbasis.so)

26 : Execution::Thread::staticMain(void*)+0x39 at ThreadMain.cpp:26 (libhdbbasis.so)

Just to be on the save side: Can you create two more call stacks to check if the threads are always working in the same coding path?

Hi Martin,

Service: preprocessor

Hierarchy:

Connection ID: -1

Thread ID: 40005

Calling:

Caller: 143632@ukgfsdbdh001:30303

Thread Type: Request

Thread Method: prep/indexing

Thread Detail: TEXT/_SYS_REPO:ACTIVE_OBJECTen.CDATA:69353

Duration (ms): 1593712

call stack for Thread ID : 40005

1 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::NormalizationBuffer::trimTrailingPendingChars()+0x50 at NormalizationBuffer.cpp:375 (libtadatstructureanalyzer.so)

2 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::NormalizationBuffer::addChar(unsigned short)+0x154 at NormalizationBuffer.cpp:287 (libtadatstructureanalyzer.so)

3 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::XMLTextParser::endElement(SAP::TextAnalysis::Strings::UString const&, int)+0x2a at XMLTextParser.cpp:154 (libtadatstructureanalyzer.so)

4 : SAP::TextAnalysis::XMLParser::XMLParserImpl::endElement(unsigned short const*)+0x52 at XMLParserImpl.cpp:427 (libtadatutilities.so)

5 : xercesc_3_1::SAXParser::startElement(xercesc_3_1::XMLElementDecl const&, unsigned int, unsigned short const*, xercesc_3_1::RefVectorOf<xercesc_3_1::XMLAttr> const&, unsigned long, bool, bool)+0x230 at XMLElementDecl.hpp:500 (libxerces-c-3.1.so)

6 : xercesc_3_1::IGXMLScanner::scanStartTag(bool&)+0xb63 at IGXMLScanner.cpp:2098 (libxerces-c-3.1.so)

7 : xercesc_3_1::IGXMLScanner::scanContent()+0x1c0 at IGXMLScanner.cpp:892 (libxerces-c-3.1.so)

8 : xercesc_3_1::IGXMLScanner::scanDocument(xercesc_3_1::InputSource const&)+0x94 at IGXMLScanner.cpp:217 (libxerces-c-3.1.so)

9 : xercesc_3_1::SAXParser::parse(xercesc_3_1::InputSource const&)+0x96 at SAXParser.cpp:575 (libxerces-c-3.1.so)

10 : SAP::TextAnalysis::XMLParser::XMLParserImpl::parse(SAP::TextAnalysis::Strings::UString const&, SAP::TextAnalysis::Strings::UString const&, bool)+0x1ea at XMLParserImpl.cpp:204 (libtadatutilities.so)

11 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::XMLTextParser::process(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Annotation>, int&)+0xa3 at XMLTextParser.cpp:52 (libtadatstructureanalyzer.so)

12 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::XMLDetagger::process(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Annotation>, int&)+0x154 at XMLDetagger.cpp:148 (libtadatstructureanalyzer.so)

13 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::StructureAnalyzer::StructureAnalyzerImpl::analyze(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Document>)+0xc63 at StructureAnalyzerImpl.cpp:160 (libtadatstructureanalyzer.so)

14 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::StructureAnalyzer::analyze(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Document>)+0x21 at StructureAnalyzer.cpp:93 (libtadatstructureanalyzer.so)

15 : preprocessor::TextAnalysisController::analyze(SAP::TextAnalysis::Pointer<SAP::TextAnalysis::AnalysisModel::Document> const&, ltt::map<ltt::basic_string<char, ltt::char_traits<char> >, ltt::basic_string<char, ltt::char_traits<char> >, ltt::less<ltt::basic_s

16 : preprocessor::PreprocessorImpl::tasdkActivity(unsigned int, TRexCommonObjects::SingleCell&, TRexCommonObjects::SingleColumn const&, preprocessor::ConfigParameters const&, unsigned short, ltt::basic_string<char, ltt::char_traits<char> > const&, bool) const+

17 : preprocessor::PreprocessorImpl::process(unsigned int, unsigned int const&, TRexCommonObjects::SingleCell&, TRexCommonObjects::SingleColumn const&, preprocessor::ConfigParameters const&, int&, TrexService::HandlerContext&, ltt::basic_string<char, ltt::char_

18 : preprocessor::Preprocessor::dispatch(unsigned int, unsigned short, int&, TRexCommonObjects::DocumentContainer&, TrexService::HandlerContext&, ltt_adp::vector<ltt::tuple<unsigned int, unsigned int, int, ltt::null_type, ltt::null_type, ltt::null_type, ltt::n

19 : preprocessor::Preprocessor::handleIndexing(unsigned int, unsigned short, int&, TRexCommonObjects::DocumentContainer&, TrexService::HandlerContext&, ltt_adp::vector<ltt::tuple<unsigned int, unsigned int, int, ltt::null_type, ltt::null_type, ltt::null_type,

20 : preprocessor::Preprocessor::handle(TrexNet::Request&, TrexService::HandlerContext&)+0x2e4 at Preprocessor.cpp:392 (hdbpreprocessor)

21 : TrexService::WorkerThread::run(void*)+0x6c0 at TrexServiceThreads.cpp:546 (libhdbbasement.so)

22 : TrexThreads::PoolThread::run()+0x968 at PoolThread.cpp:274 (libhdbbasement.so)

23 : TrexThreads::PoolThread::run(void*&)+0x10 at PoolThread.cpp:124 (libhdbbasement.so)

24 : Execution::Thread::staticMainImp(void**)+0x875 at Thread.cpp:496 (libhdbbasis.so)

25 : Execution::Thread::staticMain(void*)+0x39 at ThreadMain.cpp:26 (libhdbbasis.so)

Thread 2 :

Service: preprocessor

Hierarchy:

Connection ID: -1

Thread ID: 139211

Calling:

Caller: <Hostname>:*

Thread Type: Request

Thread Method: prep/indexing

Thread Detail: TEXT/_SYS_REPO:ACTIVE_OBJECTen.CDATA:69353

Duration (ms): 8573791

call stack for Thread ID: 139211:

1 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::NormalizationBuffer::trimTrailingPendingChars()+0x50 at NormalizationBuffer.cpp:375 (libtadatstructureanalyzer.so)

2 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::NormalizationBuffer::addChar(unsigned short)+0x154 at NormalizationBuffer.cpp:287 (libtadatstructureanalyzer.so)

3 : SAP::TextAnalysis::DocumentAnalysis::StructureAnalysis::XMLTextParser::startElement(SAP::TextAnalysis::Strings::UString const&, SAP::TextAnalysis::Properties::PropertyMap const&, int)+0x32 at XMLTextParser.cpp:89 (libtadatstructureanalyzer.so)

4 : SAP::TextAnalysis::XMLParser::XMLParserImpl::startElement(unsigned short const*, xercesc_3_1::AttributeList&)+0xe3 at XMLParserImpl.cpp:409 (libtadatutilities.so)