IT35916: SELECT ON SYSSQLSTAT CAN END IN AN ENDLESS LOOP AND CAN BLOCK THE SESSION MUTEX

APAR status

• Closed as program error.

Error description

• When a select on syssqlstat is facing an internal issue, the
  thread can end in an endless loop.
  The thread is blocking the session mutex too.
  
  Example for the select:
  SELECT sqs_sqlerror, sqs_isamerror, count(*) num_sessions FROM
  syssqlstat
  
  Stack (taken with a debugger):
  
  #0 0x00007f34cd8fe630 in sigprocmask () from /lib64/libc.so.6
  #1 0x0000000001416833 in mt_sighold ()
  #2 0x0000000001414387 in mt_ex_throw_sig ()
  #3 0x000000000141e0c3 in afsig_handler ()
  #4 <signal handler called>
  #5 0x000000000091c8fc in prsqlstat ()
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of Informix Server prior to 12.10.xC15 and 14.10.xC6.  *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to Informix Server 12.10.xC15 (when available) or    *
  * 14.10.xC6 (when available).                                  *
  ****************************************************************
  

Problem conclusion

• Fixed in Informix Server 12.10.xC15 and 14.10.xC6.
  

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

  INFORMIX SERVER

• Fixed component ID

  5725A3900

Applicable component levels