PI81076: ServerSession numberOfNonPooledConnectionsUsed can become invalid when Exception is thrown connecting

Fixes are available

APAR status

Closed as program error.

Error description

When using non-pooled Connections, such as when using
Eclipselink's Auditing capability to override the DataSource
when creating a new EntityManager, a counter of non-pooled
connections is maintained.  Unless configured to allow for
unlimited non-pooled Connections, when a maximum is reached
a service thread attempting to create a new non-pooled
Connection must block until another thread releases a
non-pooled Connection.

Bugs affecting the accuracy of the non-pooled connections
counter were found in the logic controlling the creation of
new non-pooled connections as well as the disposal of
non-pooled connections.  The result was an introduction of
an inaccuracy to the counter that caused it to have a higher
value than the actual number of non-pooled connections.
When the number of non-pooled connections is constrained
(the default is 50), this can lead to the counter reaching
the maximum, preventing any new non-pooled connections from
being created and permanently blocking threads requesting
for new non-pooled connections.

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server Liberty - Java Persistence API       *
*                  (JPA)                                       *
****************************************************************
* PROBLEM DESCRIPTION: Eclipselink's counter of non-pooled     *
*                      connections can become innaccurate and  *
*                      lead to deadlocks                       *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
When using non-pooled Connections, such as when using
Eclipselink's Auditing capability to override the DataSource
when creating a new EntityManager, a counter of non-pooled
connections is maintained.  Unless configured to allow for
unlimited non-pooled Connections, when a maximum is reached a
service thread attempting to create a new non-pooled Connection
must block until another thread releases a non-pooled
Connection.
Bugs affecting the accuracy of the non-pooled connections
counter were found in the logic controlling the creation of new
non-pooled connections as well as the disposal of non-pooled
connections.  This can occur if a DatabaseException occurs
while
creating the Connection or trying to dispose of it.  The result
was an introduction of an inaccuracy to the counter that caused
it to have a higher value than the actual number of non-pooled
connections.  When the number of non-pooled connections is
constrained (the default is 50), this can lead to the counter
reaching the maximum, preventing any new non-pooled connections
from being created and permanently blocking threads requesting
for new non-pooled connections.

Problem conclusion

The affected pathways have been updated to catch
DatabaseException and adjust the non-pooled connection counter
to the correct value before rethrowing the DatabaseException.

The fix for this APAR is currently targeted for inclusion in
Liberty fix pack 17.0.0.2 and WebSphere fix pack 9.0.0.5.
Please refer to the Recommended Updates page for delivery
information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Comments

APAR Information

APAR number
PI81076
Reported component name
LIBERTY PROFILE
Reported component ID
5724J0814
Reported release
855
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-05-04
Closed date
2017-05-18
Last modified date
2017-06-05

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
LIBERTY PROFILE
Fixed component ID
5724J0814

Applicable component levels

R855 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"855","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
04 May 2022

Tips

PI81076: ServerSession numberOfNonPooledConnectionsUsed can become invalid when Exception is thrown connecting

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

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

Fixed component ID

Applicable component levels

R855 PSY

Document Information

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