IT37973: MQ internal program amqoampx hangs which prevents MQ REST web server from restarting

APAR status

• Closed as program error.

Error description

• The MQ program amqoampx hung in the C library routine fgets,
  when its parent process (MQ REST web server) had died shortly
  after starting it. This prevented the web server from
  restarting, because the amqoampx process had inherited an open
  socket bound to the web server's listening address+port, but was
  not ending, so was not releasing the binding.
  
  This error might also be seen: MQWB1123E: The status of the
  mqweb server applications cannot be determined.
  

Local fix

• Find the amqoampx process in the ps -ef list and end it by
  sending it a signal.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users who use the MQ REST web server, and who are using
  AUTHENMD(OS) or AUTHENMD(PAM) to obtain authentication via OS or
  PAM.
  
  
  Platforms affected:
  Solaris x86-64, Solaris SPARC, Linux on zSeries, Linux on
  x86-64, Linux on Power, IBM iSeries, AIX
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The amqoampx program uses fgets (from the C runtime library) to
  read input from the parent process via a pipe.  The fgets call
  can hang if the parent process exits before it has written its
  data to the pipe.
  

Problem conclusion

• The IBM MQ code has been changed to use a non-blocking socket
  and read()/poll() calls to ensure it cannot hang.  This change
  has been made in both the amqoampx and amqoamax programs.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.1 LTS   9.1.0.11
  v9.2 LTS   9.2.0.5
  v9.x CD    9.2.5
  
  The latest available maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

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

  IBM MQ BASE MP

• Fixed component ID

  5724H7271

Applicable component levels