DB2 - Problem description
Problem IT16615 | Status: Closed |
WHEN INTRA_PARALLEL IS ON QUERIES USING HASH JOINS MAY HANG AND NOT BE ABLE TO BE FORCED OFF | |
product: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problem description: | |
Systems using INTRA_PARALLEL=YES may see an agent stuck in 'Application status' = UOW Executing. The stack of this coordinator agent may show: sqlrr_fetch_error sqlrr_open sqljsParseRdbAccessed All its subagents are in sqloXlatchConflict and at least one will show a nested sqlri_hsjnFlushBlocks call meaning it dead locks with itself: sqloXlatchConflict sqlri_hsjnFlushBlocks... sqlri_hsjnHeapReduction... sqlri_hsjnGetTupleBlock... sqlri_hsjnFlushBlocks... ... db2pd -latches shows all subagents waiting for the same latch SQLO_LT_sqlriSectInit_C__dynamic_xlatch, but there is no holder of this latch: Latch Waiters With No Holders: Address Holder Waiter Filename LOC LatchType 0x0A000100117FAC00 0 97631 sqlktins.C 50 SQLO_LT_sqlriSectInit_C__dynamic_xlatch 0x0A000100117FAB80 0 97888 sqlktins.C 50 SQLO_LT_sqlriSectInit_C__dynamic_xlatch 0x0A000100117FAC00 0 98145 sqlktins.C 50 SQLO_LT_sqlriSectInit_C__dynamic_xlatch 0x0A000100117FAC00 0 98402 sqlktins.C 50 SQLO_LT_sqlriSectInit_C__dynamic_xlatch Trying to force this application does not work. It keeps running. If this application was doing an insert/update/delete operation, you may run into of log_full situation. The only way out of this situation is to kill the db2 instance. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Db2 10.5 Fix Pack 9 or higher * **************************************************************** | |
Local Fix: | |
Use a fixed value for sortheap, instead of letting STMM tuning it. Check db2diag.log for sortheap tuning entries and chose a value at the upper end in order to avoid having too low sortheap memory. | |
Solution | |
First fixed in Db2 10.5 Fix Pack 9 | |
Workaround | |
not known / see Local fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 16.08.2016 29.09.2017 29.09.2017 |
Problem solved at the following versions (IBM BugInfos) | |
9.0. | |
Problem solved according to the fixlist(s) of the following version(s) |