DB2 - Problem description
Problem IC66767 | Status: Closed |
ONLINE BACKUP PERFORMANCE REGRESSION if tablespaces have many containers | |
product: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problem description: | |
Online backup at V9.7 GA slow compared to previous versions if the tablespaces have many containers (typically 32 or more). A symptom is that the read I/O on the server is not being driven intensively. Analysing stack from a db2pd -stack will show that only 1 of the db2 prefetchers (db2pfchr) is doing work, whereas the remainder are idle. That is there would be 1 stack similar to the following : Stack: ====================== 0x090000000006226C pread64 + 0x34 0x09000000030036CC sqloReadBlocks + 0x18 0x0900000002B94E54 sqlbReadBlocks__FP16SqlbOpenFileInfoPvlUlUiPUlP12SQLB_GLOBALS + 0x100 0x090000000300D1DC @28@sqlbDMSReadContainerData__FP17SQLB_DIRECT_IO_CBP13SQLB_MAP_I NFOP16SqlbOpenFileInfoPcP12SQLB_GLOBALS + 0x28 0x090000000300CF1C sqlbDMSDirectRead__FP17SQLB_DIRECT_IO_CB + 0x400 0x0900000002B9018C sqlbDirectRead__FP17SQLB_DIRECT_IO_CB + 0x10C 0x090000000390E7AC sqlbServiceDirectReadRequest__FP11SQLB_pfMisc + 0x684 0x09000000029E7660 sqlbPFPrefetcherEntryPoint__FPcUi + 0x444 0x0900000002FB610C sqloCreateEDU__FPFPcUi_vPcUlP13SQLO_EDU_INFOPi + 0x268 0x0900000002F6956C @49@sqloRunGDS__Fv + 0xDC with all the other db2 prefetchers having stacks similar to the following : Stack: ====================== 0x09000000001D6394 msgrcv + 0xB0 0x09000000030850FC .sqloCSemP_fdprpro_clone_929 + 0x144 0x0900000003085328 .sqlbpfRemoveFromQ__FP12SQLB_pfQUEUEUlPP14SQLB_pfRequestP8sqledb cbPP12SQLD_OBJ_HDLP12SQLB_GLOBALS_fdprpro_clone_93 + 0x15C 0x0900000003085CB0 sqlbPFPrefetcherEntryPoint__FPcUi + 0x100 0x0900000002FB610C sqloCreateEDU__FPFPcUi_vPcUlP13SQLO_EDU_INFOPi + 0x268 0x0900000002F6956C @49@sqloRunGDS__Fv + 0xDC 0x0900000002FB4D0C sqloInitEDUServices + 0x178 0x0900000002FAED84 @49@sqloSystemControllerMain__FCUiPFv_iPFi_vPPvCPi + 0x33C 0x0900000002FB0438 sqloRunInstance + 0xA8 0x00000001000029F8 DB2main + 0x930 | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * Same as error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 9.7 FP2 to resolve this issue. * **************************************************************** | |
Local Fix: | |
Rearrange the tablespaces so that there are less containers per tablespace - typically less than 32. | |
available fix packs: | |
DB2 Version 9.7 Fix Pack 2 for Linux, UNIX, and Windows | |
Solution | |
Problem first fixed in DB2 9.7 Fixpack 2 | |
Workaround | |
not known / see Local fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 01.03.2010 08.07.2010 10.08.2011 |
Problem solved at the following versions (IBM BugInfos) | |
9.7.FP2 | |
Problem solved according to the fixlist(s) of the following version(s) | |
9.7.0.2 |