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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

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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 number

    PH34514

  • Reported component name

    WEBSPHERE FOR Z

  • Reported component ID

    5655I3500

  • Reported release

    900

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2021-02-15

  • Closed date

    2021-04-20

  • Last modified date

    2021-04-20

  • 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

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"900"}]

Document Information

Modified date:
21 April 2021