A fix is available
APAR status
Closed as program error.
Error description
SINGLE ENCLAVE SUPPORT FOR CP QUERY PARALLELISM DB2PARALL/K
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All DB2 9 users of CP query parallelism. * **************************************************************** * PROBLEM DESCRIPTION: When a parallel query is offloaded to * * the zIIP engines, each parallel task * * is scheduled in its own enclave and * * managed by Work Load Manager as such. * * * * As a result, there is no way for a * * user to consistently define periods * * to distinguish between, for example, * * individual enclaves of a * * high-consumption query from a * * single enclave of a low-consumption * * query. This limits a user's ability * * to utilize WLM to favor * * low-consumption workloads. * **************************************************************** * RECOMMENDATION: * **************************************************************** Because z/OS did not initially provide a TIMEUSED support to include a time-on-CP function vs. time-on-zIIP for multiple SRBs in an enclave, each parallel task needed to be scheduled in its own enclave in order to extract the correct the accounting information. However, that created a problem where WLM could not make the distinction between one of many enclaves belonging to a high-consumption query from a single enclave belonging to a low-consumption query. As such, a user cannot define periods that consistently favor low-consumption queries.
Problem conclusion
DB2 code has been modified to create only one enclave for all parallel tasks under a query. This allows WLM to manage each query as a whole, and properly distinguish between high-consumption queries and low-consumption queries so that users can define periods to consistently favor one set or the other.
Temporary fix
Comments
APAR Information
APAR number
PM06953
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
910
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-02-05
Closed date
2010-07-16
Last modified date
2011-04-27
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK58871
Modules/Macros
DSNDACE DSNDTMQE DSNDTMT DSNTTENE DSNTTRUN DSNTTTC DSNWAACT DSNWMCRS DSNWVAPR DSNWVSR1 DSNWVZPS DSNWVZSA DSNXERT DSNX9CAL DSNX9SPI DSNX9SPS DSNX9WCA
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
R910 PSY UK58871
UP10/07/31 P F007
Fix is available
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Document Information
Modified date:
27 April 2011