PH41413: RECOVER STALE PIDFILE ON Z/OS

APAR status

• Closed as program error.

Error description

• If the operating system halts abruptly, a stale logs/httpd.pid
  file may be leftover and prevent a subsequent start of IBM HTTP
  Server
  
  Startup will report: httpd (pid 67123) already running
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM HTTP Server on z/OS        *
  ****************************************************************
  * PROBLEM DESCRIPTION: If the operating system halts           *
  *                      abruptly, a stale logs/httpd.pid        *
  *                      file may be leftover and prevent a      *
  *                      subsequent start of IBM HTTP            *
  *                      Server                                  *
  *                      Startup will report: httpd (pid         *
  *                      67123) already running                  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Under normal conditions, a stale pid in the pidfile will not
  block startup. Portable code in Apache ignores it in the
  following cases:
  1. The file is cleaned up on shutdown
  2. The new process sends signal 0 to the listed process,
  which will fail if the process is not running or is running
  under a different ID.
  For #2, on z/OS sending signal 0 does not do a permission
  check. When the OS is restarted, another process may reuse
  our old pid and cannot be detected with the portable code.
  

Problem conclusion

• The code was updated for z/OS to check at startup, if there
  is a process with the value saved in logs/httpd.pid, to make
  sure it's accessible by the current process AND that it has
  "httpd" in the command-line.  This code uses "ps -fp" to
  perform both checks.
  
  The fix for this APAR is targeted for inclusion in IBM HTTP
  Server fix packs 8.5.5.21 and 9.0.5.11. For more
  information, see 'Recommended Updates for WebSphere
  Application Server':
  https://www.ibm.com/support/pages/node/715553
  

Temporary fix

Comments

APAR Information

• 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

  WAS IHS ZOS

• Fixed component ID

  5655I3510

Applicable component levels