PI80719: Websocket race condition on writing data while closing can hang a thread

Fixes are available

APAR status

Closed as program error.

Error description

websocket race condition on writing data while closing can
hang a thread

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server Liberty - Channel Framework          *
****************************************************************
* PROBLEM DESCRIPTION: Thread leak can occur when a websocket  *
*                      session is writing data and the client  *
*                      closes the socket before closing the    *
*                      session                                 *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
There is a race condition that has a small chance of happening
when the websocket server is writing a message and the client
closes the connection without properly closing the websocket
session with a close frame.  This race condition does not affect
the program's functionality, but will cause a thread to hang,
and the hanging thread can be see in a javacore.

Problem conclusion

The problem was fixed by programatically removing the race
condition, and to better handle the case where the websocket
session is closed abruptly by the client when the client does
not send a websocket close frame.

The fix for this APAR is currently targeted for inclusion in fix
pack 17.0.0.2  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
PI80719
Reported component name
WAS LIBERTY COR
Reported component ID
5725L2900
Reported release
CD0
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-04-27
Closed date
2017-05-18
Last modified date
2017-05-18

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
WAS LIBERTY COR
Fixed component ID
5725L2900

Applicable component levels

RCD0 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSD28V","label":"WebSphere Application Server Liberty Core"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"CD0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
04 May 2022

Tips

PI80719: Websocket race condition on writing data while closing can hang a thread

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

RCD0 PSY

Document Information

Share your feedback

Need support?