PH58487: In IPv4/IPv6 dual stack environments, Intelligent Management enabled web servers and ODRs sporadically return 404/503

APAR status

• Closed as program error.

Error description

• Intelligent Management enabled web servers (IMWS) and On
  Demand Routers (ODR) sporadically return 404s and/or 503s in
  error when the WebSphere cell is configured on systems with
  IPv4/IPv6 dual stack networking enabled.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server Network Deployment leveraging        *
  *                  Intelligent Management enabled web server   *
  *                  and/or On Demand Router features within     *
  *                  IPv4/IPv6 dual stack networking enabled     *
  *                  environments.                               *
  ****************************************************************
  * PROBLEM DESCRIPTION: In IPv4/IPv6 dual stack environments,   *
  *                      Intelligent Management enabled web      *
  *                      servers and ODRs sporadically return    *
  *                      404/503.                                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Intelligent Management enabled web servers (IMWS) and On Demand
  Routers (ODR) rely on On Demand Configuration (ODC) data to
  determine routing information. ODC is a distributed in-memory
  representation of the live WebSphere Application Server Network
  Deployment (ND) topology and uses the Intelligent Management
  communication layer (P2P/SON) to transfer ODC data between
  processes in the ND topology. In IPv4/IPv6 dual stack networking
  enabled environments, as processes are restarted the P2P/SON
  ANCHOR_PROBE logic may not resume correctly which causes issues
  in ODC data transfer that result in the distributed data between
  processes becoming out of sync and inconsistent. The
  inconsistency in ODC data from an end-user perspective surfaces
  as IMWSs and/or ODRs sporadically returning 404/503 status codes
  in error.
  

Problem conclusion

• The Intelligent Management communication layer (P2P/SON) was
  altered to ensure the P2P/SON ANCHOR_PROBE logic resumes
  correctly in IPv4/IPv6 dual stack networking enabled
  environments. This allows the distributed On Demand
  Configuration (ODC) data to remain consistent and alleviates the
  sporadic return of erroneous 404/503 status codes from
  Intelligent Management enabled web servers (IMWS) and On Demand
  Routers (ODR).
  
  The fix for this APAR is targeted for inclusion in fix packs
  8.5.5.25 and 9.0.5.19. For more information, see 'Recommended
  Updates for WebSphere Application Server':
  https://www.ibm.com/support/pages/node/715553
  

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

  WEBS APP SERV N

• Fixed component ID

  5724H8800

Applicable component levels