Fixes are available
APAR status
Closed as program error.
Error description
Page cleaning often occurs in bufferpools to reduce the active log space being held up by dirty pages. In doing so, the page cleaners might encounter some pages from temporary object that are currently in use. On platforms without asynchronous IO, the page cleaners will wait until the temporary pages are released. During this period the page cleaners will stop all page cleaning activities, therefore allowing the dirty pages in the bufferpool to build up. If the temporary pages are not released soon enough then this could cause the active log space to accumulate, even past the softmax settings. Since the temporary pages do not play a part in recovery, cleaning them out will not help with reducing the active log space, therefore it is not necessary to clean out the temporary pages. The fix is to prevent the page cleaners from waiting on any temporary pages that are currently in use. Symptoms: 1. The following message appears in the db2diag.log 2009-11-24-10.37.49.841169+060 E14193576A697 LEVEL: Warning PID : 15055 TID : 1 PROC : db2agent (TEST) 0 INSTANCE: TEST NODE : 000 DB : TEST APPHDL : 0-2114 APPID: 10.21.22.58.51460.091124093715 AUTHID : TEST FUNCTION: DB2 UDB, data protection services, sqlpgResSpace, probe:1660 MESSAGE : ADM1822W The active log is being held by dirty pages. This is not an error, but database performance may be impacted. If possible, reduce the database work load. If this problem persists, either decrease the SOFTMAX and/or increase the NUM_IOCLEANERS DB configuration parameters. Also check if the active log space held by dirty pages substantially exceeds the softmax settings. 2. SET WRITE SUSPEND takes a long time to finish. The stack will show that it is waiting for pausing the page cleaners, and the page cleaners are waiting on page latches.
Local fix
Workaround: 1. Avoid using long running statements with temporary objects 2. Use a large sortheap to avoid spilling
Problem summary
**************************************************************** * USERS AFFECTED: * * All * **************************************************************** * PROBLEM DESCRIPTION: * * Page cleaning often occurs in bufferpools to reduce the * * active * * log space being held up by dirty pages. In doing so, the * * page * * cleaners might encounter some pages from temporary object * * that * * are currently in use. On platforms without asynchronous IO, * * the * * page cleaners will wait until the temporary pages are * * released. * * During this period the page cleaners will stop all page * * cleaning * * activities, therefore allowing the dirty pages in the * * bufferpool * * to build up. If the temporary pages are not released soon * * * * enough then this could cause the active log space to * * accumulate, * * even past the softmax settings. * * * * * * * * Since the temporary pages do not play a part in recovery, * * * * cleaning them out will not help with reducing the active log * * * * space, therefore it is not necessary to clean out the * * temporary * * pages. The fix is to prevent the page cleaners from waiting * * on * * any temporary pages that are currently in use. * * * * * * * * Symptoms: * * * * 1. The following message appears in the db2diag.log * * * * * * * * 2009-11-24-10.37.49.841169+060 E14193576A697 LEVEL: * * Warning * * PID : 15055 TID : 1 PROC : * * * * db2agent (TEST) * * * * 0 * * * * INSTANCE: TEST NODE : 000 DB : TEST * * APPHDL : 0-2114 APPID: * * * * 10.21.22.58.51460.091124093715 * * * * AUTHID : TEST * * * * FUNCTION: DB2 UDB, data protection services, sqlpgResSpace, * * * * probe:1660 * * * * MESSAGE : ADM1822W The active log is being held by dirty * * pages. * * This is not an error, but database performance may be * * impacted. * * If possible, reduce the database work load. If this problem * * * * persists, either decrease the SOFTMAX and/or increase the * * * * NUM_IOCLEANERS DB configuration parameters. * * * * * * * * Also check if the active log space held by dirty pages * * * * substantially exceeds the softmax settings. * * * * * * * * 2. SET WRITE SUSPEND takes a long time to finish. The stack * * * * will show that it is waiting for pausing the page cleaners, * * and * * the page cleaners are waiting on page latches. * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 V9.5 FP6 * ****************************************************************
Problem conclusion
First fixed in DB2 V9.5 FP6
Temporary fix
Comments
APAR Information
APAR number
IZ65866
Reported component name
DB2 UDB ESE HP-
Reported component ID
5765F4103
Reported release
950
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-12-01
Closed date
2010-07-12
Last modified date
2010-07-12
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
DB2 UDB ESE HP-
Fixed component ID
5765F4103
Applicable component levels
R950 PSY
UP
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Document Information
Modified date:
06 October 2021