DB2 - Problembeschreibung
Problem IC87121 | Status: Geschlossen |
BUFFER POOL DECREASE / STMM HANG WAITING ON SPECIAL TEMP BUFFER POOL PAGE | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 | |
Problembeschreibung: | |
Buffer pool decreases, often initiated by STMM, may hang for long periods due to special system temporary pages that are being held in the buffer pool. If STMM initiated the buffer pool decrease, it will be hung and unable to respond to changes in workload or memory availability. The "special temp pages" in question are for internal system temporary objects that are cached for reuse until application termination. A common triggering scenario is performing special operations such as create index or runstats on user temporary tables (declared or created global temporary tables). The workaround is to avoid decreasing or fix the sizes of buffer pools associated with system temporary tablespaces. Note that although the triggering activity may be associated with user temporary tables in "user" temporary tablespaces, the internal objects are created in the "system" temporary tablespaces. If STMM is inoperative for long periods of time, and user temporary tables are commonly created on the system, this is the likely source of the problem. One way of determining that STMM is hung is that regular configuration updates cease. A second is that the STMM logs stop being updated. The STMM thread, db2stmm, regularly writes messages to the STMM logs (in DIAGPATH/stmmlog). Note db2agent threads may still write messages to the STMM logs. A call stack of the db2stmm thread will show that it is in the midst of a buffer pool decrease : thread_wait getConflictComplex getConflict getConflict sqlbSecurePageProtection sqlbRemInvalidPagesFromBufferPool sqlbDecreaseBufferpoolSize sqlbResizeBufferPool sqlbAlterAutomaticBufferPool | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * Systems with STMM tuning a buffer pool with an associated * * temporary table space * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to the latest fix pack. * **************************************************************** | |
Local-Fix: | |
Fix the sizes of buffer pools associated with system temporary table spaces. | |
verfügbare FixPacks: | |
DB2 Version 10.1 Fix Pack 2 for Linux, UNIX, and Windows | |
Lösung | |
Problem was first fixed in DB2 UDB version 10.1 fix pack 2. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 10.10.2012 20.12.2012 20.12.2012 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
10.1.0.2 | |
10.5.0.2 |