PQ83400: ASYNC BEANS AND WORKMANAGER WILL BLOCK WHEN QUEUE SIZE IS EXCEEDED BY MORE THAN10 REQUESTS

 A fix is available

5.0.2.6: WebSphere Application Server Enterprise 5.0.2 Cumulative Fix 6



APAR status
Closed as program error.

Error description
Async beans and workmanager will block when queue size is
Local fix Problem summary
****************************************************************
* USERS AFFECTED: All Asynchronous Beans developers using      *
*                 WebSphere Application Server 5.0.2.2         *
****************************************************************
* PROBLEM DESCRIPTION: WorkManager.startWork() methods always  *
*                      block when the underlying thread pool   *
*                      and request buffer is full.             *
****************************************************************
* RECOMMENDATION: If developers would like to receive an       *
*                 exception when the thread pool and           *
*                 request buffer is full and would like        *
*                 to adjust the size of the request buffer,    *
*                 then apply fix PQ83400 on WebSphere          *
*                 Enterprise 5.0.2.2 and WebSphere             *
*                 Application Server cumulative fix 5.0.2.4.   *
****************************************************************
WorkManager.startWork() methods always block when the
underlying thread pool and request buffer is full.

This behavior makes it difficult for OLTP applications
to be responsive.  Application developers would like
to have the startWork() methods return immediately and
allow handling of insufficient resources in other ways.
Problem conclusion
The Work Manager configuration object now supports two
custom properties that allow configuring the size of the
associated thread pool input buffer and the behavior of the
thread pool when it is full.  The default behavior of the
Work Manager thread pool is to block all input requests
until a thread has been freed.  Work is submitted to
the thread pool using one of the
com.ibm.websphere.asynchbeans.WorkManager.startWork() methods.
The default size of the buffer is undefined.  Therefore, if
you desire more predictable behavior the following custom
properties can be set on the Work Manager configuration
resourcein the Administration Console or WSADMIN:

Name:       WORKREQUEST_QUEUE_SIZE
Type:       java.lang.Integer
Range:      1 to (2½32)-1
Default:        Unspecified
Description:    Specifies the size of the buffer that
                the Work Manager's thread pool
                uses to pull requests from.  The total
                number of in-flight requests
                will be the sum of Max Threads
                and WORKREQUEST_QUEUE_SIZE.
Notes:          Use with extreme caution.  Specifying a
                large value can lead to instability and
                memory resource issues.

Name:           WORKREQUEST_QUEUE_FULL_ACTION
Type:           java.lang.Integer
Values:         0 = Block, 1=FAIL
Default:        0
Description:    If 0 is specified and the thread pool is
                unable to immediately allocate a thread
                or a free slot in the buffer, the request
                will block indefinitely until a thread
                becomes available in the pool.  This is
                the default behavior.

                If 1 is specified and the thread pool is
                unable to immediately allocate a thread or
                a free slot in the buffer, a
                WorkRejectedException with an error code of
                WorkRejectedException.WORKREQUEST_QUEUE_FULL
                will be thrown.  The request can be retried
                until successful.  The WorkRejectedException
                may be thrown any time where a thread
                cannot be immediately be allocated and
                may not reflect the size of the thread pool
                and buffer.
Temporary fix Comments
APAR information
APAR number PQ83400
Reported component name WAS ENTERPRISE
Reported component ID 5630A3700
Reported release 00W
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2004-01-19
Closed date 2004-02-26
Last modified date 2004-02-26

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros

Publications Referenced

Fix information

Applicable component levels
R003 PSY    UP
R00A PSY    UP
R00H PSY    UP
R00I PSY    UP
R00S PSY    UP
R00W PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Enterprise Edition (EE)
Operating system(s):
Software version: 00W
Software edition:
Reference #: PQ83400
IBM Group: Software Group
Modified date: Feb 26, 2004