APAR status
Closed as program error.
Error description
Informix instances with several thousand connected sessions may experience poor performance of queries using the sysscblst pseudo-table or syssessions view in the sysmaster database. Statements such as "select count(*) from sysscblst" may take several seconds to run during which time other threads may be observed to wait on the session mutex. In addition advisory messages may appear in the online message log: Performance Advisory: Unable to get session latch. Results: This can happen during high connectivity periods where sessions are allocated and freed frequently. Action: This can impact session and tenant limits processing and low memory manager processing. The thread performing the sysscblst query may frequently be in the running state. The following is an example stack for the thread: yield_processor_mvp mt_unlock_helper mt_nxtscb mt_prscblst pstread pst_rsread rsread fmread readseq_single gettupl scan_next next_row group_open prepselect open_cursor sql_open sq_open sqmain In addition there may be delays in connecting new sessions or in the disconnection of existing sessions whilst the query is active.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: * * Users of Informix Server prior to 12.10.xC15 and 14.10.xC5. * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Informix Server 12.10.xC15 (when available) or * * 14.10.xC5. * ****************************************************************
Problem conclusion
Fixed in Informix Server 12.10.xC15 and 14.10.xC5.
Temporary fix
Comments
APAR Information
APAR number
IT34183
Reported component name
INFORMIX SERVER
Reported component ID
5725A3900
Reported release
C10
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-09-11
Closed date
2021-02-02
Last modified date
2021-02-02
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
INFORMIX SERVER
Fixed component ID
5725A3900
Applicable component levels
[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSGU8G","label":"Informix Servers"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"C10"}]
Document Information
Modified date:
03 February 2021