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Problem IT28743
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Status: Closed |
ADMIN_MOVE_TABLE: MISLEADING ERROR MESSAGE REFERRING TO SEMAPHORES. SQL2102N REASON CODE 33
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| product: |
DB2 FOR LUW / DB2FORLUW / B10 - DB2 |
| Problem description: |
The error message SQL2102N reason code 33 with text "The maximum
number of retries was exceeded when trying to acquire a
semaphore." might be reported in ADMIN_MOVE_TABLE (AMT) phases
INIT, SWAP and CANCEL. These phases execute many catalog
operations such as RENAME INDEX/TABLE, ALTER INDEX/TABLE,
TRANSFER OWNERSHIP etc. In order to avoid locking conflicts on
the system catalog with other applications a semaphore mechanism
is implemented within admin_move_table.
Most users first think of OS semaphore resource bottleneck, when
they get to read the message text of SQL2102N reason code 33.
However this message doesn't refer to OS semaphores at all.
Rather it refers to the serialization and retry mechanism inside
AMT before issuing a lot of catalog operations consecutively.
With this fix admin_move_table will report the usual SQL0911N
reason code 68 (lock timeout) errors instead of SQL2102N reason
code 33.
The semaphore is realized as an exclusive lock on the table
SYSTOOLS.OTM_SEMAPHORE_TABLE. This should reflect the root cause
more clearly of not being able to acquire a semaphore within the
locktimeout period while performing catalog operations. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to the latest fix pack. *
**************************************************************** |
| Local Fix: |
Apply fixpack |
| Solution |
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| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 10.04.2019
18.01.2020
18.01.2020 |
| Problem solved at the following versions (IBM BugInfos) |
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| Problem solved according to the fixlist(s) of the following version(s) |
