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Problem IT36337
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Status: Closed |
PREFETCHERS INFINITELY LOOPING IN SQLBSERVICELEAFREQUEST
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| product: |
DB2 FOR LUW / DB2FORLUW / B50 - DB2 |
| Problem description: |
Prefetchers may infinitely loop in sqlbServiceLeafRequest if a
table space's prefetch size is set to 0. The infinite looping
will appear to a user as Db2 utilizing a high amount of CPU
(nearly 100%) while the database is otherwise idle.
sqlbServiceLeafRequest is used to prefetch index leaf pages and
their associated data pages, so this issue may be triggered by
any workload that has index prefetching.
A stack dump will show one or more prefetchers with a stack
similar to the following:
sqliBreakUpAndSendRequests
sqlbServiceLeafRequest
sqlbPFPrefetcherEntryPoint
sqbPrefetcherEdu::RunEDU() |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* all *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to 11.5.6 *
**************************************************************** |
| Local Fix: |
Set the prefetch size for all table spaces to a non-zero value.
This can be done with "ALTER TABLESPACE
PREFETCHSIZE ". |
| Solution |
|
| Workaround |
****************************************************************
* USERS AFFECTED: *
* all *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to 11.5.6 *
**************************************************************** |
| Comment |
Upgrade to 11.5.6 |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 24.03.2021
11.06.2021
26.06.2021 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
