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PM79119: DFHSO0126 CREATE SOCKET FAILED, MAXSOCKETS LIMIT REACHED AFTER MANY SOCKET ERRORS FOR LONG RUNNING TASKS

A fix is available

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APAR status

  • Closed as program error.

Error description

  • You have long running tasks in CICS issuing EXEC CICS INVOKE
    WEBSERVICE that experience socket errors such as socket connect
    failures.
    .
    DFHWBCL is responsible for creating and connecting the new
    socket. If this succeeds, the socket reference is held in a WBO
    block (web session block). The web session block is returned to
    the webservice pipeline component of CICS. The pipeline code
    will close this web session (which closes and deallocates the
    sockets related resources.)
    before returning to the issuer of EXEC CICS INVOKE WEBSERVICE.
    However, if the socket connect fails DFHWBCL discards the WBO
    session block (which references the allocated socket) and
    returns an error to the pipeline component of CICS without first
    deallocating the socket.The only thing that will deallocate the
    socket is recovery manager whichcalls socket domain at
    end-of-task syncpoint.
    EXEC CICS SYNCPOINT will NOT trigger socket deallocation.
    DFHWBCL should strictly speaking perform cleanup after the
    socket connection error.
    

Local fix

  • Terminate long running task and restart it.
    KIXREVRJL
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS users.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: MAXSOCKETS limit reached after many     *
    *                      sockets connecting errors for long      *
    *                      running tasks.                          *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Long running tasks in CICS issuing EXEC CICS INVOKE
    WEBSERVICE that experience sockets connect failures.
    
    DFHWBCL open_session is responsible for creating the web
    session from client to server. It creates and connects the
    new socket. The code will not close the socket if its
    connecting fails.
    
    Generally, CICS will close the socket during task end by
    recovery manager. The sockets will remain in CICS if it's a
    long running task. CICS then reaches MAXSOCKETS limit after
    many socket connect errors for those long running tasks.
    

Problem conclusion

  • DFHWBCL has been changed to clean up the socket related
    resources just after its connecting failure.
    

Temporary fix

  • FIX AVAILABLE BY PTF ONLY
    

Comments

APAR Information

  • APAR number

    PM79119

  • Reported component name

    CICSTS V3 Z/OS

  • Reported component ID

    5655M1500

  • Reported release

    500

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-12-13

  • Closed date

    2013-03-18

  • Last modified date

    2013-04-02

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

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

    PM83825 PM83827 UK92671

Modules/Macros

  •    DFHWBCL
    

Fix information

  • Fixed component name

    CICSTS V3 Z/OS

  • Fixed component ID

    5655M1500

Applicable component levels

  • R500 PSY UK92671

       UP13/03/29 P F303

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.

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Document Information

Modified date:
02 April 2013