DB2 - Problem description
Problem IC76825 | Status: Closed |
THREADED DB2FMP PROCESS LOOPS IN ITS SIGNAL HANDLER WHEN IT RECEIVES NESTED SIGNALS | |
product: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problem description: | |
A threaded db2fmp process loops in its signal handler when it receives nested signals. Once that happens, db2agent EDUs requesting new fenced stored procedures to run can wait forever on SQLO_LT_sqlerFmpRow__ipcLatch. You can find the following from db2pd -latches output: Database Partition 14 -- Active -- Up 20 days 23:46:45 -- Date 05/31/2011 10:52:58 Address Holder Waiter Filename LOC LatchType 0x07800000007EDE64 0 32946 Unknown 6931 SQLO_LT_sqlerFmpRow__ipcLatch 0x07800000007EDE64 0 33210 Unknown 6931 SQLO_LT_sqlerFmpRow__ipcLatch 0x07800000007EDE64 0 36542 Unknown 6931 SQLO_LT_sqlerFmpRow__ipcLatch And the db2agent holding SQLO_LT_sqlerFmpRow__ipcLatch is waiting for a response via semaphore from the spinning db2fmp process. It has a stack similar to following one: <StackTrace> -------Frame------ ------Function + Offset------ 0x0900000000247820 semop + 0xC0 0x0900000010AF631C sqloSSemP + 0x1F8 0x0900000010D00968 @53@sqlccipcWaitSynch__FP18SQLCC_INITSTRUCT_T + 0x1D4 0x0900000010D00BD0 sqlccipcinit + 0x218 0x0900000010D006D0 sqlccinit__FP18SQLCC_INITSTRUCT_TPP17SQLCC_COMHANDLE_TP12SQLCC_C OND_TP13SQLO_MEM_POOL + 0x250 0x090000000E144834 @136@sqlerInitCommsLayer__FP14sqlerFmpHandleP8sqeAgentb + 0xCC 0x090000000DF5F0A8 @136@sqlerMasterThreadReq__FP13sqlerFmpParmsP13sqlerFmpTableP14s qlerFmpHandleP18sqlerFmpThreadListP8sqeAgentUicT7P5sqlcab + 0x610 0x090000000DF9FDE4 sqlerGetFmpThreadEntry__FP11sqlerFmpRowP14sqlerFmpHandleP13sqler FmpParmsb + 0x29C 0x090000000DF9FA64 sqlerGetFmpThreadEntry__FP11sqlerFmpRowP14sqlerFmpHandleP13sqler FmpParmsb@glue345 + 0x78 0x090000000D502A94 sqlerGetFmpFromPool__FP14sqlerFmpHandleP13sqlerFmpParms + 0x400 0x0900000010CFDB98 sqlerInvokeFencedRoutine__FP13sqlerFmpParms + 0xAC 0x0900000010C7A358 sqlriInvokeInvoker__FP10sqlri_ufobb + 0x84 0x090000000D730FB0 sqlriutf__FP8sqlrr_cb + 0xE8 0x090000000EC927DC sqlri_tfopn__FP8sqlrr_cbP9sqlri_tao + 0x27C 0x090000000D26C7A4 sqlriopn__FP8sqlrr_cbP9sqlri_taoPi + 0x998 0x0900000010A3D21C sqlriopn__FP8sqlrr_cbP9sqlri_taoPi@glue220 + 0x74 0x0900000010A615FC sqlrita__FP8sqlrr_cb + 0x214 0x0900000010A6536C sqlriSectInvoke__FP8sqlrr_cbP12sqlri_opparm + 0x610 0x090000000DD5371C sqlrr_dss_router__FP8sqlrr_cb + 0x34 0x090000000DAB8900 sqlrr_subagent_router__FP8sqeAgentP12SQLE_DB2RA_T + 0x5C0 0x090000000CD4B664 sqleSubRequestRouter__FP8sqeAgentPUiT2 + 0x5F8 0x090000000DAB33E0 sqleProcessSubRequest__FP8sqeAgent + 0xA4C 0x090000000CE59EB4 RunEDU__8sqeAgentFv + 0x2F8 0x0900000010C1AF90 EDUDriver__9sqzEDUObjFv + 0xDC 0x0900000010C02770 sqloEDUEntry + 0x260 </StackTrace> | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * THREADED DB2FMP PROCESS LOOPS IN ITS SIGNAL HANDLER WHEN IT * * RECEIVES NESTED SIGNALS * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 LUW Version 9.7 Fix Pack 5 * **************************************************************** | |
Local Fix: | |
To identify which partition is experiencing the symptom: db2_all "db2pd -latches" | grep -E "Database Partition|Holder|SQLO_LT_sqlerFmpRow__ipcLatch" Look for Database Partition which holds the latch. To recover for the symptom: login to the physical box where above problem Database Partition resides: ps -ef | grep "db2fmp" | grep ") <database partition num>" From above output, find and terminate the PID which keeps consuming CPU: db2fmpterm <PID> | |
available fix packs: | |
DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows | |
Solution | |
Problem was first fixed in Version 9.7 Fix Pack 5 | |
Workaround | |
See LOCAL fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 06.06.2011 16.12.2011 03.01.2012 |
Problem solved at the following versions (IBM BugInfos) | |
9.7.FP5 | |
Problem solved according to the fixlist(s) of the following version(s) | |
9.7.0.5 |