IC98464: TRANSFER HANGS WHEN USING WMQ MANAGED FILE TRANSFER V7.5.0.2 PROTOCOL BRIDGE AGENT TO ACCESS FTP SERVER.

WebSphere MQ V7.5 Fix Pack 7.5.0.4

APAR status

• Closed as program error.

Error description

• A hang in the transfer process is experienced when using
  the WMQ MFT v7.5.0.2 Protocol Bridge Agent to access an
  FTP server.
  .
  The agent cannot be stopped with the fteStopAgent command.
  The process must be killed manually.
  .
  Once the agent is restarted, the file is transfer completes.
  .
  Javacore from the protocol bridge agent taken at the time
  of the hang shows a number of threads with the following
  call stack:
   at java/net/PlainSocketImpl.socketAccept(Native Method)
   at java/net/PlainSocketImpl.
   accept(PlainSocketImpl.java:438(Compiled Code))
   at java/net/ServerSocket.
   implAccept(ServerSocket.java:462(Compiled Code))
   at java/net/ServerSocket.
   accept(ServerSocket.java:430(Compiled Code))
   at org/apache/commons/net/ftp/FTPClient.
   _openDataConnection_(FTPClient.java:489(Compiled Code))
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of the WebSphere MQ Managed File
  Transfer component, who have protocol bridge agents that connect
  to an FTP Server using active FTP mode.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM SUMMARY:
  When using active FTP, the protocol bridge agent establishes:
  
  - A control connection to an FTP server when it starts up
  - Data connections to an FTP server whenever it needs to
  transfer files.
  
  The control connection remains open when the protocol bridge
  agent is running, and is only closed when the protocol bridge
  agent is stopped.
  
  Data connections are created whenever the protocol bridge
  agent needs to communicate with an FTP server to handle a
  transfer request. Once a transfer request has completed, the
  data connection is closed.
  
  
  If an FTP server becomes unresponsive while the protocol
  bridge agent was running, the protocol bridge agent would wait
  indefinitely for the FTP server to respond when creating or
  using a data connection. When this happened, any active
  transfers would become blocked and no new transfers would be
  started. In addition to this, it was not possible to stop the
  protocol bridge agent.
  

Problem conclusion

• The protocol bridge agent provided with WebSphere MQ Managed
  File Transfer has now been updated to allow users to specify a
  timeout that will be used when:
  
  - Establishing a data connection to an FTP server.
  - Waiting to receive data from an FTP server over an already
  established data connection.
  
  To set the timeout, add the following entry to the
  agent.properties file for the protocol bridge agent:
  
  protocolBridgeDataTimeout=
  
  and restart the protocol bridge agent.
  
  If the timeout specified by the protocolBridgeDataTimeout
  property elapses, then the protocol bridge agent will attempt to
  reconnect to the FTP server and resume the transfer. If a new
  connection to the FTP server cannot be established, the transfer
  will fail.
  
  If the property is not specified, or is set to 0, then the
  protocol bridge agent will wait indefinitely when establishing a
  data connection, or receiving data over an existing data
  connection.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.5       7.5.0.4
  
  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

  WMQ FTE

• Fixed component ID

  5724H7242

Applicable component levels

• R750 PSY

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