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PI17154: SERVER USING FRCA WILL OCCASIONALLY NOT RESPOND TO LOCAL CLIENT

A fix is available

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APAR status

  • Closed as program error.

Error description

  • .
    The web server is setup to use the Fast Response Cache
    Accelerator (EnableFRCA On is specified in the httpd.conf file).
    When clients are running on the same system, occasionally the
    first (only) request sent on a connection will not get a
    response from the server.  The server's logs will not show any
    information for the affected connections.
                                                                   .
    

Local fix

  • .
    Use one of the following options to avoid this problem:
    
     - Disable FRCA on this server.
    
          EnableFRCA Off
    
     - Enable a packet trace, even if filters prevent any packets
       from being recorded:
    
          VARY TCPIP,tcpipname,PKKTRACE,ON,PROT=240
    
     - The following command may be entered every time TCPIP is
       recycled:
    
          MODIFY tcpipname,FRLSOFF
    
    
    
    Other symptoms:
    
    A SYSTCPIP CTRACE with OPTIONS=(AFP,TCP) will show an 'FrLS
    exit' record for the client side of the affected connection
    before the 'Afpa Add Connection Entry' record for the server
    side of the connection.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All users of the Communications Server for                   *
    * z/OS Version 2 Release(s) 1 IP                               *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * TCP/IP client connections to Web Server                      *
    * using FRCA time out.                                         *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply PTF                                                    *
    ****************************************************************
    

Problem conclusion

  • TCP connection times out attempting to connect to a Web Server
    using FRCA. This occurs when the client and server are on the
    same TCP/IP stack. In this scenario, the Faster Local Sockets
    function may be employed on the first write of data before the
    connection has transitioned to use FRCA. This invalid scenario
    should be protected with locks. However, the client side does
    not obtain the correct tcb lock preventing the necessary
    synchronization.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI17154

  • Reported component name

    TCP/IP V3 MVS

  • Reported component ID

    5655HAL00

  • Reported release

    210

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-05-02

  • Closed date

    2014-06-12

  • Last modified date

    2014-09-03

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

    PI15839

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

    UI18784

Modules/Macros

  • EZBT6FWR EZBTCFWR
    

Fix information

  • Fixed component name

    TCP/IP V3 MVS

  • Fixed component ID

    5655HAL00

Applicable component levels

  • R210 PSY UI18784

       UP14/08/09 P F408

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:
03 September 2014