PK81500: SLOW CONNECTIONS ON JAX-WS WEB SERVICES FOR FEATURE PACK CLIENT

Fixes are available

APAR status

Closed as program error.

Error description

You might experience slow connections on the Web Services
client that are caused by a code defect in outbound Web Services
client connection pool. The symptom might be performance
degradation or "java.net.SocketTimeoutException: Async operation
timed out" exceptions on the Web Services client.

Local fix

```
N/A.
```

Problem summary

****************************************************************
* USERS AFFECTED:  WebSphere Application Server Feature Pack   *
*                  for Web Services users of JAX-WS Web        *
*                  Services                                    *
****************************************************************
* PROBLEM DESCRIPTION: A high number of web serivces requests  *
*                      for new hosts connections can result    *
*                      in degraded throughput.                 *
****************************************************************
* RECOMMENDATION:  Install a fix pack containing this APAR     *
****************************************************************
To improve performance, the web service client engine
maintains connection objects for some hosts after the
connection is closed (soft connections).  When subsequent
requests for the same host arrive, the client engine can use an
existing soft connection object instead creating a new
connection.

As a result, the client connection pool contains "in use"
connections, invalid connections, and recently used "soft"
connections.

If the client engine requests a connection to a new host and
the pool of connections is full, the requesting thread enters
a wait state.  Under normal circumstances, the waiting thread
is quickly awakened.

Problems occur if there is a burst of connection requests for
new hosts.  This high load can cause a large number of threads
to enter the wait state.   The large number of waiting threads
can degrade the overall throughput of the system.  (Note that
you may not see any failures, but may observe a severe
degradation in throughput.)

Problem conclusion

The solution is to aggressively free the "soft connections"
when this particular kind of high load scenario is detected.

There is now a JVM property that determines how many waiting
connection requests are tolerated before agressively freeing
soft connections. The new JVM property is
"com.ibm.websphere.webservices.http.waitingThreadsThreshold"
and the default value is 5.
By default, once 5 threads are waiting for connections, the
client engine will aggressively remove soft connections.

Note that this change will not help in the situation where all
of the connections are actually in use.  That situation can
only be improved by increasing the maximum connection limit
(and probably the maximum threads).

This fix also ensures that certain invalid connections are
removed from the pool.

The fix for this APAR is currently targeted for inclusion in
fix packs 6.1.0.25 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
PK81500
Reported component name
WEBSPHERE APP S
Reported component ID
5724J0800
Reported release
610
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-02-26
Closed date
2009-03-21
Last modified date
2009-03-21

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
WEBSERVIC FEATU
Fixed component ID
5724J0850

Applicable component levels

R610 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":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
29 December 2021

Tips

PK81500: SLOW CONNECTIONS ON JAX-WS WEB SERVICES FOR FEATURE PACK CLIENT

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

R610 PSY

Document Information

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