PK83875: FIREWALL CONNECTION TIMEOUTS CAUSE LISTENER PORTS TO STOP WITH WMSG0036E MESSAGES, DUE TO LONG LIVED SERVERSESSION OBJECTS

Fixes are available

APAR status

Closed as new function.

Error description

When a firewall is configured to time out inactive connections
between WebSphere Application Server and WebSphere MQ, a
listener port may write the following log entry to the JVM
logs of an application server and stop:
WMSG0036E: Maximum message delivery retry count of {0} reached
for MDB {1}, JMSDestination {2}, MDBListener stopped

The exception that causes the listener port to stop in this
case is not caused by application code, instead it is caused
by a WebSphere MQ JMS exception showing reason code 2009
(MQRC_CONNECTION_BROKEN) caused by a SocketException exception.

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  Users of IBM WebSphere Application Server   *
*                  using IBM WebSphere MQ as a messaging       *
*                  provider, with a firewall between the       *
*                  application server and the queue manager.   *
****************************************************************
* PROBLEM DESCRIPTION: A listener port holds JMS sessions      *
*                      open indefinitely after it creates      *
*                      them, regardless of the session         *
*                      pool configuration.                     *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
A listener port creates server sessions dynamically when
required, up to the number specified in the maximum sessions
parameter of the listener port. Each server session is
associated with a JMS session obtained from the session pool
of the JMS connection factory. Once a session has been created,
it is not closed (and released back into the session pool)
until the listener port is stopped. This means that a JMS
session may be idle for long periods of time, during which it
is not eligible for cleanup by the session pool.

If a firewall is configured to terminate idle connections,
this can cause the network connections for the sessions that
are owned by the listener port to be closed by the firewall.
The closed network connections cause 2009
(MQRC_CONNECTION_BROKEN) exceptions to be thrown when the
listener port attempts to use the sessions to deliver
messages, which in turn might cause the listener port to stop
with WMSG0036E messages.

Problem conclusion

The fix for this APAR introduces the following message
listener service custom properties, which allow monitoring
of sessions owned by the listener port to be enabled, and for
idle sessions to be returned to the session pool of the JMS
connection factory:

Name: SERVER.SESSION.POOL.REAP.TIME
Default value: -1 (disabled)
Valid values: Any positive number of seconds
Description: Defines the interval in seconds between checks of
server session pools by the server session pool maintenance
thread. This property must be set to a non-negative value to
enable server session pool monitoring.

Name: SERVER.SESSION.POOL.UNUSED.TIMEOUT
Default value: -1 (disabled)
Valid values: Any positive number of seconds
Description: defines the default server session pool timeout in
seconds. When set to a non-negative value, the server session
pool maintenance thread will compare this to the current time
minus the last time a server session was used, and, if less,
the server session will be remove from the server session pool
and its JMS session returned to the JMS session pool.
For example: if this value is set to 1 and a particular server
session was last used 2 seconds ago it will be removed from
the server session pool and its JMS session will be returned
to the JMS session pool.

Name: SERVER.SESSION.POOL.UNUSED.TIMEOUT.lpname
Where 'lpname' is the name of the listener port.
Default value: The value of SERVER.SESSION.POOL.UNUSED.TIMEOUT
Valid values: Any positive number of seconds
Description: Used to over-ride the default
SERVER.SESSION.POOL.UNUSED.TIMEOUT value for the listener port
with name "lpname". If this is set to a non-negative value
this will be used by the server session pool maintenance
thread instead of the value specified by the
SERVER.SESSION.POOL.UNUSED.TIMEOUT property. NB: this applies
even if the value of SERVER.SESSION.POOL.UNUSED.TIMEOUT is
negative, in which case it enables server session pool
monitoring for the specified listener port only. Similarly, if
this value is negative it disables server session pool
monitoring for the specified listener port. Note that this
value affects all MDBs using the specified listener port.

In order to enable server session pool monitoring in WebSphere
Application Server for z/OS, the following custom property
must be configured on the connection factory used by the
listener port, in addition to specifying the message listener
port custom properties described above:
Name:  was_nondeferredreaper
Value: true

If the NON.ASF.RECEIVE.TIMEOUT message listener service
property is set to a positive integer, server session pool
monitoring cannot be used, and the properties listed above
should not be changed from their default values.

The fix for this APAR is currently targeted for inclusion in
fix pack 6.0.2.37, 6.1.0.27 and 7.0.0.5.  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
PK83875
Reported component name
PLAT MSG COM
Reported component ID
620400101
Reported release
100
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-04-01
Closed date
2009-05-22
Last modified date
2009-05-22

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
PLAT MSG COM
Fixed component ID
620400101

Applicable component levels

R100 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":"6.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
29 December 2021

Tips

PK83875: FIREWALL CONNECTION TIMEOUTS CAUSE LISTENER PORTS TO STOP WITH WMSG0036E MESSAGES, DUE TO LONG LIVED SERVERSESSION OBJECTS

Fixes are available

Subscribe

APAR status

Closed as new function.

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

R100 PSY

Document Information

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