IZ58011: TN3270 SERVER HALTS WITH SNATNSRVR_MT PROCESS DEFUNCT

Communications Server for AIX, Version 6.4 -- Latest PTFs

APAR status

• Closed as program error.

Error description

• Communications Server for Linux, Version 6.4
  --------------------------------------------
  TN3270 Server halts and all tn3270 clients lose connection.
  The snatnsrvr_mt process is <defunct> in the process table and
  produces a core dump (if core dumps are enabled).
  

Local fix

Problem summary

• *
  * USERS AFFECTED: All users of the TN3270 Server function.
  *
  * PROBLEM SUMMARY:
  * All tn3270 clients lose connection to the server. On the
  * server, the snatnsrvr_mt process is gone or <defunct>, and
  * a core dump is produced if core dumps are enabled.
  *
  

Problem conclusion

• When a tn3270 (not tn3270e) client is connected and there is
  some back pressure from the TCP/IP socket to the client (a
  socket write has to be retried) and there is a partial chain
  of data queued after another chain (probably the two messages
  BC,EC followed by BC),we incorrectly dequeue the second BC
  when retrying the TCP/IP write, and this leads to the core
  dump. Code has been corrected to handle this situation
  properly.
  

Temporary fix

• snatnsrvr_mt
  

Comments

APAR Information

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

  LI74809

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

Modules/Macros

• SNATNSRV
  

Fix information

• Fixed component name

  CS AIX V6.X

• Fixed component ID

  5765E5100

Applicable component levels

• R640 PSY U828838

     UP09/10/27 I 1000