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":"LOB45","label":"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