PM38306: NULLPOINTEREXCEPTION IN ZAIOTCPCHANNEL.JAVA AND POSSIBLE HANG: COM.IBM.WS.TCP.CHANNEL.IMPL.ZAIOTCPCHANNEL.NEWCONNECTIONCOMMON

Fixes are available

APAR status

Closed as program error.

Error description

The Control Region may write an FFDC file containing a
NullPointerException similar to the stack trace below. This
may be followed cause a number of symptoms including server
hang and non responsive outbound requests from applications.

FFDC file:
----------
key = java.lang.NullPointerException
com.ibm.ws.tcp.channel.ZAioTCPChannel 200
Exception = java.lang.NullPointerException
Source = com.ibm.ws.tcp.channel.ZAioTCPChannel
probeid = 200
Stack Dump = java.lang.NullPointerException
 at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannel.newConnectionCommon(Z
AioTCPChannel.java:680)
 at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannel.readCompletedNewConne
ction(ZAioTCPChannel.java:524)
 at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannelCPPUtilitiesInterfaceI
mpl.readCompletedNewConnection(ZAioTCPChannelCPPUtilitiesInterfa
ceImpl.java:82)
 at
com.ibm.ws390.tcp.channel.ZAioTCPChannelCPPUtilities.readComplet
edNewConnection(ZAioTCPChannelCPPUtilities.java:79)

Dump of callerThis =
Object type = com.ibm.ws.tcp.channel.impl.ZAioTCPChannel
com.ibm.ws.tcp.channel.impl.ZAioTCPChannel@33a833a8

Exception = java.lang.NullPointerException
Source = com.ibm.ws.tcp.channel.ZAioTCPChannel
probeid = 200
Dump of callerThis =
Object type = com.ibm.ws.tcp.channel.impl.ZAioTCPChannel
com.ibm.ws.tcp.channel.impl.ZAioTCPChannel@33a833a8
--------

ZAioTCPChannel=all tracing during time of problem will also show
the NullPointerException:

--
 Trace: 2011/05/02 08:16:38.863 01 t=8C8490 c=UNK key=S2
(13007002)
   ThreadId: 00000039
   FunctionName:
com.ibm.ws.tcp.channel.impl.ZAioTCPBaseRequestContext
   SourceId:
com.ibm.ws.tcp.channel.impl.ZAioTCPBaseRequestContext
   Category: FINEST
   ExtendedMessage: setBuffer:java.nio.DirectByteBuffer[pos=39
lim=8192
cap=8192]
 Trace: 2011/05/02 08:16:38.875 01 t=8C8490 c=UNK key=S2
(13007002)
   ThreadId: 00000039
   FunctionName: com.ibm.ws.tcp.channel.impl.ZAioTCPChannel
   SourceId: com.ibm.ws.tcp.channel.impl.ZAioTCPChannel
   Category: FINE
   ExtendedMessage: ZAioTCPChannel: httpclient-tcp-outbound -
Exception
occurred while processing new client connection: ; java.lang.
 NullPointerException
  at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannel.newConnectionCommon(Z
AioTCPCh
annel.java:680)
  at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannel.readCompletedNewConne
ction(ZA
ioTCPChannel.java:524)
  at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannelCPPUtilitiesInterfaceI
mpl.read
CompletedNewConnection(ZAioTCPChannelCPPUtilitiesInterfa
 ceImpl.java:82)
  at
com.ibm.ws390.tcp.channel.ZAioTCPChannelCPPUtilities.readComplet
edNewCon
nection(ZAioTCPChannelCPPUtilities.java:79)
0Trace: 2011/05/02 08:16:38.876 01 t=8C8490 c=UNK key=S2
(13007002)
   ThreadId: 00000039
   FunctionName: newConnectionCommon
   SourceId: com.ibm.ws.tcp.channel.impl.ZAioTCPChannel
   Category: FINER
   ExtendedMessage: Exit; rc=-1
--

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server V6.1.0                               *
****************************************************************
* PROBLEM DESCRIPTION: A WebSphere Application Server for z/OS *
*                      server suddenly stops accepting inbound *
*                      work immediately after an outbound      *
*                      channel chain was started.              *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
When a WebSphere Application Server for z/OS server starts a
channel chain, an internal data structure is updated with
details of the TCP channel in the chain.  When multiple chains
(generally outbound chains) are started over time, it is
possible for this data structure to become corrupted by the new
outbound TCP channel.  The symptoms will vary depending on how
the data structure is corrupted.  If an inbound IIOP channel
chain is corrupted, the server will stop responding to inbound
IIOP requests without printing any error messages at all.  If
an inbound HTTP channel chain is corrupted, the server will stop
responding to new HTTP requests and an FFDC record similar to
the following will be seen:

java.lang.NullPointerException at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannel.newConnectionCommon
    (ZAioTCPChannel.java:680) at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannel.readCompletedNewConne
ction
    (ZAioTCPChannel.java:524) at
com.ibm.ws.tcp.channel.impl.ZAioTCPChannelCPPUtilitiesInterfaceI
mpl.readCompletedNewConnection
    (ZAioTCPChannelCPPUtilitiesInterfaceImpl.java:82) at
com.ibm.ws390.tcp.channel.ZAioTCPChannelCPPUtilities.readComplet
edNewConnection
    (ZAioTCPChannelCPPUtilities.java:79)

Although the above FFDC record will only be printed the first
time the error is seen, the FFDC summary data will show that
the NullPointerException occurs once per inbound HTTP request.

Problem conclusion

Code was fixed so that the TCP channel data structure is no
longer corrupted when multiple channel chains are started.

APAR PM38306 is currently targeted for inclusion in
Service Level (Fix Pack) 6.1.0.41 of WebSphere
Application Server V6.1.

Please refer to URL:
//www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
for Fix Pack availability.

Temporary fix

Comments

APAR Information

APAR number
PM38306
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
610
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2011-05-03
Closed date
2011-05-31
Last modified date
2011-12-02

APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:

PM38307

Fix information

Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500

Applicable component levels

R610 PSY UK73054
UP11/11/03 P F111

Fix is available

Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
27 October 2021

Tips

PM38306: NULLPOINTEREXCEPTION IN ZAIOTCPCHANNEL.JAVA AND POSSIBLE HANG: COM.IBM.WS.TCP.CHANNEL.IMPL.ZAIOTCPCHANNEL.NEWCONNECTIONCOMMON

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 UK73054

Fix is available

Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

Document Information

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