APAR status
Closed as program error.
Error description
The initial 'Blocked:ARCHIVE' phase of a backup can extend siginifcantly depending on the size of the TBLSpace TBLSpace partitions in the spaces to be backed up, which in turn usually is correlated with the number of tables/fragments/indices in the system. In that phase the backup determines the exact set of pages (used extents) that need to go to this particular backup. This situation seems to be heavily aggravated by the fact that all the disk i/o potentially related with this task is done direclty, without taking advantage of read-ahead. Informix versions 12.10.xC14 and onwards prevent this extra disk i/o waiting by implementing read-ahead.
Local fix
Pre-populate the bufferpool with required pages shortly before starting the backup, by running following stored procedure: create procedure tblspace_tblspace2bufferpool() define i,c int; define max_spaceno int; let max_spaceno = (select max(dbsnum) from sysdbspaces); for i in (1 to max_spaceno) select count(*) into c from syspaghdr pgh, sysptnhdr pth where pth.partnum = pgh.pg_partnum and pth.partnum = i*1024*1024+1 and pg_pagenum < npused; end for; end procedure;
Problem summary
**************************************************************** * USERS AFFECTED: * * Users of Informix Server prior to 12.10.xC14 and 14.10.xC4. * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Update to Informix Server 12.10.xC14 or 14.10.xC4. * ****************************************************************
Problem conclusion
Fixed in Informix Server 12.10.xC14 and 14.10.xC4.
Temporary fix
Comments
APAR Information
APAR number
IT32602
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
2020-04-20
Closed date
2020-06-08
Last modified date
2020-06-08
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
[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSGU8G","label":"Informix Servers"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Line of Business":{"code":"LOB10","label":"Data and AI"}}]
Document Information
Modified date:
10 June 2020