REXEC FAILS - TOO MANY OPEN CONNECTIONS ALREADY EXIST

 
 APAR Identifier ...... PQ87840      Last Changed ........ 04/08/13
 REXEC FAILS - TOO MANY OPEN CONNECTIONS ALREADY EXIST
 
 Symptom ...... IN INCORROUT         Status ........... CLOSED  PRS
 Severity ................... 3      Date Closed ......... 04/08/13
 Component .......... 5735FAL00      Duplicate of ........
 Reported Release ......... 440      Fixed Release ............
 Component Name TCP/IP V2 FOR V      Special Notice
 Current Target Date ..              Flags
 SCP ...................
 Platform ............
 
 Status Detail: APARCLOSURE - APAR is being closed.
 
 PE PTF List:
 
 PTF List:
 
 Parent APAR:
 Child APAR list:
 
 ERROR DESCRIPTION:
 Customer runs the REXEC command in a disconnected virtual
 machine at regular intervals (approximately four times per
 hour).  After a few days, the REXEC command no longer runs
 successfully.  An REXEC client trace indicates that too many
 connection are already opened:
   ...
   Connecting to SYS xx.xx.xx.xx, port REXEC (512)
   Passive Conn - Too many open connections already exist on loca
                  PORT 65535
   Too many open connections already exist
   Unable to open passive port for host SYS
   ...
 
 The virtual machine must be recycled (re-IPLed) in order to
 achieve successful REXEC command execution.
 
 LOCAL FIX:
 WORKAROUND: Recycle the affected machine every 48 hours.
 
 PROBLEM SUMMARY:
 ****************************************************************
 * USERS AFFECTED: All customers who concurrently use           *
 *                 Pascal-based TCP/IP functions with other     *
 *                 applications that use VMCF functions.        *
 ****************************************************************
 * PROBLEM DESCRIPTION:                                         *
 ****************************************************************
 * RECOMMENDATION: NONE                                         *
 ****************************************************************
 Unexpected connection and processing errors were encountered
 while running a locally-developed application within a
 disconnected virtual machine that makes use of both the REXEC
 and WAKEUP commands.
 
 PROBLEM CONCLUSION:
 This problem is symptomatic of a known restriction which
 previously has been documented in 'Section 3:  General
 Information', of the TCP/IP Preventive Service Planning (PSP)
 information that is applicable for a given level of TCP/IP for
 z/VM:
 
  yyyy/mm/dd  Several TCP/IP for VM functions are Pascal-based,
              and use VMCF communications to communicate with the
              TCPIP server.  Therefore, these functions cannot be
              reliably used in conjunction with other
              applications that also use VMCF communications
              (such as the CMS Utility, WAKEUP); doing so may
              produce intermittent hangs during processing or
              other unpredictable results.
 
              The TCP/IP Pascal-base functions for which such
              problems may arise are:
 
              FTP      HOMETEST LPQ    LPR     LPRM      NETSTAT
              OBEYFILE PING     REXEC  TELNET  TESTSITE  TFTP
 
              See CMS Utilities APAR VM58540 for more information
              about problems when using FTP in conjunction with
              WAKEUP.
 
 In this instance, the reported problem was resolved by modifying
 the application to use the 'CP SLEEP' command (and appropriate
 logic) instead of WAKEUP.
 
 TEMPORARY FIX:
 
 COMMENTS:
 
 MODULES/MACROS:   NA
 
 SRLS:      NONE
 
 RTN CODES:
 
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