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Problem IT34037
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Status: Closed |
DEADLATCH BETWEEN ONE THREAD WRITING A DICTIONARY TO DISK USING VECTORIZEDADC AND ANOTHER THREAD DOING A NEW EXTENT ALLOCATION
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| product: |
DB2 FOR LUW / DB2FORLUW / B10 - DB2 |
| Problem description: |
Deadlatch occurs one thread writing a dictionary to disk using
VectorizedADC and another thread doing a new extent allocation
The deadlatch is seen between latches
SQLO_LT_SQLP_SAVEPOINTS__spLatch and
SQLO_LT_SQLB_BPD__bpdLatch_SX
Function stack of the two deadlatch threads can be as below
sqloSpinLockConflict + 0x05cf
sqlpSpReq + 0x01b5
ibm_cde::data::Recovery::ScopedSavepoint::ScopedSavepoint +
0x0072
ibm_cde::data::ExtentDispenser::allocateExtent + 0x03de
ibm_cde::data::DatabaseTableAccessor::createNewPage + 0x05f3
ibm_cde::data::GeneralPageDispenser::acquireNextPage + 0x0077
ibm_cde::data::ColumnGroupWriter::createAndWritePageFromStash +
0x00fb
ibm_cde::data::ColumnGroupWriter::flushPartialPage + 0x005b
ibm_cde::data::TableColumnGroupWriter::flushPartialPages +
0x0065
ibm_cde::data::TableBulkInserter::prepareForEndOfStatement +
0x0056
ibm_cde::data::TableWriter::handleInsertCompleted + 0x0049
...
semop + 0x0007
SQLO_SLATCH_CAS64::getConflictComplex + 0x07e2
SQLO_SLATCH_CAS64::getConflict + 0x007c
sqlbGetAndMonitorPageLatch + 0x5be
sqlbfix + 0x0c97
sqlbSFVSFixPage + 0x0035
ibm_cde::data::DatabaseTableAccessor::readPage + 0x0268
ibm_cde::data::DatabaseTableAccessor::writeTableMetadata +
0x01dc
ibm_cde::data::VectorizedADC::buildDictionary + 0x0836
ibm_cde::data::VectorizedADC::mergeHistogramsFromRPC + 0x0480
ibm_cde::data::VectADCPushHistogramsRPC::unmarshalReq + 0x00eb
ibm_cde::data::BaseRPC::receive + 0x0064
ibm_cde::data::RPCHandler::receiveReq + 0x0366
ibm_cde::data::cdeRPCHandlerInterface::receiveReq + 0x006a
sqlrr_rpc_router + 0x0810
sqlrr_subagent_router + 0x0a20
sqleSubRequestRouter + 0xc93
sqleProcessSubRequest + 0x08ff |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* all *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to 11.5.5.1 or later *
**************************************************************** |
| Local Fix: |
Disable TEMP table compression
db2set
DB2_CDE_COMPRESSION_SETTINGS="ENABLE_SYNCHRONOUS_ADC_FOR_DGTT:0;
ENABLE_VECT_ADC_FOR_DGTT:0" |
| Solution |
|
| Workaround |
****************************************************************
* USERS AFFECTED: *
* all *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to 11.5.5.1 or later *
**************************************************************** |
| Comment |
Upgrade to 11.5.5.1 or later |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 28.08.2020
23.03.2021
23.03.2021 |
| Problem solved at the following versions (IBM BugInfos) |
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| Problem solved according to the fixlist(s) of the following version(s) |
