PI62169: CONCURRENT MULTIPLE LOGIN AND OPERATIONS CAUSE SIGNIFICANT SLOWDOWN TO CLEARQUEST WEB ON WINDOWS

Rational ClearQuest Fix Pack 1 (9.0.0.1) for 9.0
Rational ClearQuest Fix Pack 2 (9.0.0.2) for 9.0
Rational ClearQuest Fix Pack 3 (9.0.0.3) for 9.0
Rational ClearQuest Fix Pack 4 (9.0.0.4) for 9.0
Rational ClearQuest Fix Pack 5 (9.0.0.5) for 9.0
Rational ClearQuest Fix Pack 6 (9.0.0.6) for 9.0

APAR status

• Closed as program error.

Error description

• On ClearQuest web, attempting concurrent login and other
  operations cause significant slowdown, lock timed out error
  and/or eventual hang.
  
  The refcount mutexes appear to be causing significant slowdown
  on Windows.
  
  In the cqrpc dumps, many threads are in CreateMutex which
  suggests there may be some kind of synchronization occurring in
  mutex creation (and destruction).
  
  This is the cause since Win32 will check to see if the mutex
  already exists before trying to create it. So it has to lock on
  the entire set of mutexes. Since on Windows, mutexes are system
  wide (and exist across processes), this may also add some
  synchronization across processes.
  
  Note,
  On UNIX, the mutexes appear not to be causing any performance
  issues.
  ClearQuest 8.0.1.10 TestFix4 and later is affected by this
  defect.
  
  Steps to reproduce;
  1) Start independent browser sessions about 40 depending on the
  load performance
  2) Click login on each browser session moving one by one
  manually
  3) Extract Query folder one by one
  4) Run query on each browser
  
  Repeat 3) - 4), if possible.
  
  The login prompt and loading process slow down, hang or respond
  error.
  SystemOut.log starts recording lock timed out error and then
  thread hang message.
  

Local fix

• None
  
  Easing login or workspace load by removing query folders and
  shortcut, limiting the number of concurrent user login in a
  certain amount of time might help if not completely.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * ClearQuest Web                                               *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * ClearQuest Web might get sluggish on Windows after many      *
  * users logged in.                                             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  

Problem conclusion

• A fix is available in ClearQuest 9.0.0.1
  A change was made to eliminate the slow down on ClearQuest Web.
  

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

  CLEARQUEST WIN

• Fixed component ID

  5724G3600

Applicable component levels

• R801 PSY

     UP