IT41722: INFORMIXHQ: CLICKING ON PERFORMANCE -> SESSIONS -> SESSION ID HANGS AND THROWS "AN ATTEMPT WAS MADE TO DIVIDE BY ZERO" EXCEPTION

APAR status

• Closed as program error.

Error description

• When clicking on a Session ID under Performance -> Sessions, it
  will sometimes hang and throw a "An attempt was made to divide
  by zero" exception.
  
  This is caused by the following query because the num_sched
  column is zero.
  
  SELECT name, sysrstcb.tid AS thread_id, wait_reason, num_sched
  AS num_scheduled,
    cpu_time AS total_time, cpu_time/num_sched AS time_slice,
  vpid, priority
       AS thread_priority
  FROM sysrstcb, systcblst
  WHERE systcblst.tid = sysrstcb.tid
     AND sysrstcb.sid = 96084;> >
  
  
  1202: An attempt was made to divide by zero.
  Error in line 6
  Near character position 27
  
  
  SELECT name, sysrstcb.tid AS thread_id, wait_reason, num_sched
  AS num_scheduled,
       cpu_time AS total_time,
       --cpu_time/num_sched AS time_slice,
       vpid, priority AS thread_priority
  FROM sysrstcb, systcblst
  WHERE systcblst.tid = sysrstcb.tid
     AND sysrstcb.sid = 96084;> >
  
  
  name       sqlexec
  thread_id    99790
  wait_reason
  num_scheduled  0
  total_time    0.00
  vpid       1
  thread_priority 1
  
  1 row(s) retrieved.
  
  
  Here is a snippet of the exception from the
  informixhq-server.log:
  
  2022-07-28 15:43:42 [qtp890160158-275] ERROR
  com.informix.hq.server.rest.api.informix.SessionsResource -
  Cannot get session info
  java.sql.SQLException: An attempt was made to divide by zero.
                 at
  com.informix.util.IfxErrMsg.buildExceptionWithMessage(IfxErrMsg.
  java:422) ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.util.IfxErrMsg.buildIsamException(IfxErrMsg.java:40
  1) ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.jdbc.IfxSqli.addException(IfxSqli.java:3022)
  ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.jdbc.IfxSqli.receiveError(IfxSqli.java:3273)
  ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.jdbc.IfxSqli.dispatchMsg(IfxSqli.java:2269)
  ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.jdbc.IfxSqli.receiveMessage(IfxSqli.java:2194)
  ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.jdbc.IfxSqli.sendStatementQuery(IfxSqli.java:1524)
  ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.jdbc.IfxSqli.executeStatementQuery(IfxSqli.java:147
  4) ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.jdbc.IfxResultSet.executeQuery(IfxResultSet.java:18
  3) ~[informixhq-server.jar:2.1.0]
                 at
  com.informix.jdbc.IfxStatement.executeQueryImpl(IfxStatement.jav
  a:909) ~[informixhq-server.jar:2.1.0]
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of InformixHQ prior to 2.2.0.                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to InformixHQ 2.2.0.                                 *
  ****************************************************************
  

Problem conclusion

• Fixed in InformixHQ 2.2.0.
  

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