PH34514: WEBSPHERE Z/OS 9.0.5.2 JAVA.IO.IOEXCEPTION: XMEMPROXY CHANNEL IN SR FAILED TO READ FROM CR CHECK CR LOG/FFDC FOR MORE INFO. XMEM

APAR status

• Closed as program error.

Error description

• FFDC Exception:java.io.IOException SourceId:com.ibm.ws.webcontai
  ner.channel.WCCByteBufferInputStream ProbeId:102 Reporter:com.ib
  m.ws.webcontainer.channel.WCCByteBufferInputStream@17709467
  
  jav
  a.io.IOException: XMemProxy channel in SR failed to read from
  CR. Check CR log/ffdc for more info. xmemProxySrRead() RC=-8. Co
  nnection=XMemProxySRComm@nnnnnn:connectionHandle=ConnectionHandl
  e[],requestSequence=,orbrPtr=
  
  	at com.ibm.ws390.xmem.proxy.XMem
  ProxySRComm.readFromCr(XMemProxySRComm.java:166)
  
  	at com.ibm.ws
  390.xmem.proxy.channel.XMemProxySRInboundHttpServiceContextImpl.
  getNextHttpRequestBodyChunk(XMemProxySRInboundHttpServiceContext
  Impl.java:1389)
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server                                      *
  *                  V9.0                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION: WebSphere Application Server for z/OS   *
  *                      may hang in a Servant doing a read for  *
  *                      more data to the Controller region.     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The Servant may issue a read request to the Controller region
  over the XMem channel directed by the XMemProxySRComm class.
  There is a chance of a hang when invoking the readFromCr method
  if the prior invocation returned a java.io.IOException.
  The Controller region XMem channel code processing the
  readFromCr request from the Servant is in the
  XMemProxyCRInboundConnLink.xmemProxySrRead().  This method
  assumes that if data is not currently buffered to satisfy the
  readFromCr request then a AsyncRead must be outstanding. If
  the last read completed with an IOException (ex. from a
  Timeout)
  there will be no outstanding read on the Connection and the
  Servant thread will be "paused" in cross-memory waiting for
  a non-existence read to complete.
  The following is an example of a IOException received from
  readFromCr which encountered a Read timeout in the Controller
  region:
  FFDC Exception:java.io.IOException SourceId:com.ibm.ws.
  webcontainer.channel.WCCByteBufferInputStream ProbeId:102
  Reporter:com.ibm.ws.webcontainer.channel.
  WCCByteBufferInputStream@17709467
  java.io.IOException: XMemProxy channel in SR failed to read
  from CR. Check CR log/ffdc for more info. xmemProxySrRead()
  RC=-8. Connection=XMemProxySRComm@ffffffff8a9469d5:
  connectionHandle=ConnectionHandle[0x5011e6d570/0x359/IN:CR/
  remote],requestSequence=-2147483633,orbrPtr=54754b9470
  at com.ibm.ws390.xmem.proxy.XMemProxySRComm.readFromCr(
  XMemProxySRComm.java:166)
  at com.ibm.ws390.xmem.proxy.channel.
  XMemProxySRInboundHttpServiceContextImpl.
  getNextHttpRequestBodyChunk(
  XMemProxySRInboundHttpServiceContextImpl.java:1389)
  at com.ibm.ws390.xmem.proxy.channel.
  XMemProxySRInboundHttpServiceContextImpl.
  getNextHttpRequestBodyChunk(
  XMemProxySRInboundHttpServiceContextImpl.java:1362)
  at com.ibm.ws390.xmem.proxy.channel.
  XMemProxySRInboundHttpServiceContextImpl.
  getRequestBodyBuffer(
  XMemProxySRInboundHttpServiceContextImpl.java:1579)
  at com.ibm.ws.webcontainer.channel.WCCByteBufferInputStream.
  bufferIsGood(WCCByteBufferInputStream.java:449)
  at com.ibm.ws.webcontainer.channel.WCCByteBufferInputStream.
  read(WCCByteBufferInputStream.java:336)
  

Problem conclusion

• Code has been modified in the Controller region
  XMemProxyCRInboundConnLink class to enforce the read error
  returned on a XMemProxySRComm.readFromCr() call on subsequent
  calls as well.
  
  The fix for this APAR is targeted for inclusion in fix pack
  9.0.5.8. For more information, see 'Recommended Updates for
  WebSphere Application Server':
  https://www.ibm.com/support/pages/node/715553
  

Temporary fix

Comments

APAR Information

• 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

  WEBSPHERE FOR Z

• Fixed component ID

  5655I3500

Applicable component levels