DB2 - Problem description
Problem IT34037 | Status: Closed |
DEADLATCH BETWEEN ONE THREAD WRITING A DICTIONARY TO DISK USING VECTORIZEDADC AND ANOTHER THREAD DOING A NEW EXTENT ALLOCATION | |
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) | |
Problem solved according to the fixlist(s) of the following version(s) |