APAR status
Closed as program error.
Error description
Under some conditions, when a WebSphere eXtreme Scale domain is replicating with MMR to a second WebSphere eXtreme Scale domain, and each domain is using a write-behind loader configuration, errors might occur. If the domains are processing many short transactions to the same set of keys, one or both domains might receive intermittent LoaderException conditions. For example, a LoaderException with a KeyNotFoundException might cause a "Delete over delete is not allowed" exception message. The failed operation is inserted into the write-behind loader, but is not updated in the map, and the application is required to take action either by re-applying update operations or by repeating delete operations.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: WebSphere eXtreme Scale users who run * * multimaster replication (MMR) scenarios * * with a write-behind loader configuration. * **************************************************************** * PROBLEM DESCRIPTION: Linked MMR domains can receive * * spurious LoaderException and * * KeyNotFoundException exceptions. * **************************************************************** * RECOMMENDATION: * **************************************************************** Due to expected timing effects, linked MMR domains running many small transactions on the same set of keys can cause the transactions to be applied out of order. The write-behind loader determines that the misplaced application of transactions causes an error scenario and fails to apply the transactions.
Problem conclusion
The write-behind loader now processes the transactions in the correct order, rather than applying erroneous transactions out of order.
Temporary fix
Comments
APAR Information
APAR number
PM81046
Reported component name
WS EXTREME SCAL
Reported component ID
5724X6702
Reported release
860
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2013-01-21
Closed date
2013-06-17
Last modified date
2013-06-17
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
WS EXTREME SCAL
Fixed component ID
5724X6702
Applicable component levels
R860 PSY
UP
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Document Information
Modified date:
17 June 2013