IT48494: HTTPREPLY NODE DOES NOT LOG CLIENT COMMUNICATION ERROR IN SYSLOG

APAR status

• Closed as program error.

Error description

• In a webservice Request-Response scenario, if the Http client is
  disconnected before receiving the response from Http Reply node,
   no error is recorded in the syslog when HttpReply node tries to
  send response to the client that is no longer connected or
  available to receive the response.
  This is due to the async, non-blocking I/O model of libevent,
  where the server may send an HTTP response before the callback
  associated with the write buffer event has completed.
  This Apar enables, through introduction of an env var,  logging
  of below error in syslog when HTTPReply node tries to send the
  response back to the client which is no longer
  connected/running,
   BIP3137E: An exception occurred whilst sending reply data to
  the HTTP client: 'A connection error prevented the reply from
  being sent'
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  All users of IBM App Connect Enterprise v12 and v13
  
  
  Platforms affected:
  LinuxPPCLE64, AIX, LinuxZ64, LinuxX64, WinX64
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  In a web service Request-Response pattern, if the HTTP client
  disconnects before receiving the response from the HTTPReply
  node, no error is logged in the system log (syslog) when the
  HTTPReply node attempts to send the response to the
  now-unavailable client.
  This behavior is due to the
  asynchronous, non-blocking I/O model used by libevent, where the
  server may initiate sending the HTTP response before the write
  buffer event callback has completed. As a result, connection
  issues during this phase may not be captured or logged.
  

Problem conclusion

• This APAR introduces an environment variable
  MQSI_HTTP_CALLBACK_WAIT_INTERVAL that enables user to define a
  callback wait interval in milliseconds.  To set 1 millisecond
  wait interval on Linux/AIX system:
  
  export
  MQSI_HTTP_CALLBACK_WAIT_INTERVAL=1
  
  Following error message in
  the syslog is expected when the HTTPReply node attempts to send
  a response to a disconnected or terminated client (provided the
  'Ignore transport failures' property is unchecked on HttpReply
  node :
  
  BIP3137E: An exception occurred whilst sending reply
  data to the HTTP client: 'A connection error prevented the reply
  from being sent'
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version   Maintenance Level
  v12.0      12.0.12.18
  v13.0      13.0.5.0
  
  The latest available maintenance can be obtained from:
  http://www-01.ibm.com/support/docview.wss?rs=849&uid=swg27006041
  
  If the maintenance level is not yet available,information on
  its planned availability can be found on:
  http://www-1.ibm.com/support/docview.wss?rs=849&uid=swg27006308
  ---------------------------------------------------------------
  

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

  APP CONNECT ENT

• Fixed component ID

  5724J0560

Applicable component levels