IJ20591: Managed .NET SSL application making MQGET calls unexpectedly receives MQRC_CONNECTION_BROKEN when running in .NET Core

APAR status

• Closed as program error.

Error description

• When running the application written in .NET core using an SSL
  connect it reports an MQRC_CONNECTION_BROKEN error.
  
  The MQ error log shows:
  
                      Process(18060.1145118) User(mqm)
  Program(amqrmppa)
                      Host(XXX)
  Installation(Installation1)
                      VRMF(9.1.2.0) QMgr(QM1)
                      Time(2019-10-01T14:14:02.663Z)
                      RemoteHost(XXX)
                      ArithInsert1(104) ArithInsert2(104)
                      CommentInsert1(XXX)
                      CommentInsert2(TCP/IP)
                      CommentInsert3( read())
  
  AMQ9208E: Error on receive from host XXX.
  
  EXPLANATION:
  An error occurred receiving data from XXX over TCP/IP. This may
  be
  due to a communications failure.
  ACTION:
  The return code from the TCP/IP read() call was 104 (X'68').
  Record these
  values and tell the systems administrator.
  ----- amqccita.c : 4388
  -------------------------------------------------------
                      Process(18060.1145118) User(mqm)
  Program(amqrmppa)
                      Host(XXX)
  Installation(Installation1)
                      VRMF(9.1.2.0) QMgr(QM1)
                      Time(2019-10-01T14:14:02.664Z)
                      CommentInsert1(CH1)
                      CommentInsert2(18060)
                      CommentInsert3(XXX)
  
  AMQ9999E: Channel 'CH1' to host 'XXX' ended
  abnormally.
  
  EXPLANATION:
  The channel program running under process ID 18060 for channel
  'CH1' ended abnormally. The host name is 'XXX'; in
  some
  cases the host name cannot be determined and so is shown as
  '????'.
  
  When running the same application written in .NET Framework it
  works and nothing is written in the server log.
  

Local fix

• Setting the heartbeat interval to lower values may reduce the
  frequency of occurrence.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  User using Managed MQ .NET client with SSL enabled using .Net
  core
  
  
  Platforms affected:
  Windows, Linux on x86-64
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When application is run to get a message using SSL which is
  greater than 15KB there are two issues:
  1. If there are 2 or more messages in the queue, and .Net core
  application tries to get the message then MQRC_CONNECTION_BROKEN
  error is caught.
  2. If there is only 1 message in the queue and .Net core
  application tries to get the message then there is delay equal
  to heartbeat interval to get the message.
  
  These behaviors were caused due to differences in timeout
  behaviour between .NET Core and Framework that were not
  correctly accounted for in the design of the receiving logic.
  

Problem conclusion

• .NET managed code has been modified such that messages greater
  then 15KB can be retrieved without incurring this delay or
  connection broken error.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.2 LTS   9.2.0.5
  v9.x CD    9.3.0.0
  
  The latest available maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

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

  IBM MQ XMS V9.1

• Fixed component ID

  5724H7277

Applicable component levels