PI16626: BASIC AUTHENTICATION REQUESTS FAIL IN LIBERTY

8.5.5.3: WebSphere Application Server V8.5.5 Fix Pack 3
8.5.5.4: WebSphere Application Server V8.5.5 Fix Pack 4
8.5.5.5: WebSphere Application Server V8.5.5 Fix Pack 5
8.5.5.6: WebSphere Application Server V8.5.5 Fix Pack 6
8.5.5.7: WebSphere Application Server V8.5.5 Fix Pack 7
8.5.5.8: WebSphere Application Server V8.5.5 Fix Pack 8
8.5.5.9: WebSphere Application Server V8.5.5 Fix Pack 9
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21

APAR status

• Closed as program error.

Error description

• Liberty profile used within CICS is encountering a very high
  failure rate for BASIC AUTHENTICATION when running in a
  stressed environment.
  E.g. 512 separate HTTPS requests are sent to the server, each
  with a different USERID and each request contains the correct
  PASSWORD.
  Out of the 512 requests sent, only 287 successfully call the
  servlet they're trying to reach.
  From the remaining 225 calls:
  - 59 produce an Exception on the client side with HTTP
    response code 401.
  - 43 are never heard from again on the client side but on the
    server side following Exception can be seen:
      Exception = java.util.ConcurrentModificationException
      Source = com.ibm.ws.security.authentication.internal.jaas.
               modules.UsernameAndPasswordLoginModule
  - 123 are never heard from again,
    they are just swallowed somewhere
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server Liberty Profile                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: Under stressed environment on z/OS      *
  *                      platform, a very high failure rate      *
  *                      for basic authentication might be       *
  *                      observed.                               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Since some of the z/OS unique code was not thread safe, under
  stressed environment, some of concurrent requets for basic
  authentication failed even there were valid credentials.
  

Problem conclusion

• With this fix, the code was modified to be thread safe.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 8.5.5.3. Please refer to the Recommended Updates page
  for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

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

  LIBERTY - Z/OS

• Fixed component ID

  5655W6514

Applicable component levels

• R850 PSY

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