IT13261: FTE/MFT PROTOCOL BRIDGE AGENT: AN FTPS TRANSFER RETURNS ERROR BFGBR0186E

WebSphere MQ File Transfer Edition V7.0 Fix Pack 7.0.4.6

APAR status

• Closed as program error.

Error description

• When an MFT or FTE protocol bridge agent tries to receive a file
  or files using FTPS transfer protocol, the following errors may
  be generated:
  
  BFGSS0067W: The file has transferred successfully but the source
  agent was unable to delete the source file due to the following
  IOException:
  BFGBR0186E: The server has terminated the connection. The reply
  string sent back by the server was '426 Data connection error.
  ''
  
  This error starts to occur after the fix for APAR IC98825 is
  applied.
  
  This impacts WMQ MFT 8.0.0.3, WMQ MFT 7.5.0.4 or WMQ FTE
  7.0.4.5.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of:
  
  - WebSphere MQ File Transfer Edition V7.0.4
  - The WebSphere MQ V7.5 Managed File Transfer component.
  - The MQ V8.0 Managed File Transfer component.
  
  who have protocol bridge agents that act as the source agent for
  managed transfers, and that process managed transfer requests
  that have:
  
  - The -cs (checksum) option set to "none".
  - And the -sd (source disposition) option set to "delete".
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When a managed transfer request is submitted, users can specify:
  
  - Whether a checksum algorithm should be run to ensure that the
  file has been transferred successfully.
  - If the source file to be deleted if it is successfully
  transferred (this is known as "source disposition")
  
  These are specified by the -cs and -sd options on the
  fteCreateTransfer command.
  
  If a managed transfer is submitted with the source disposition
  option set to "delete" and the managed transfer completes
  successfully, the source agent for that transfer will perform
  some checks to ensure that the source file has not been modified
  in between the file data being sent to the destination agent and
  the source disposition being processed. If the file has been
  modified during these times, then the source agent will not
  delete the file as it has changed since it was transferred.
  
  The checks that are performed on the source file are determined
  by the -cs option that was passed into the fteCreateTransfer
  command that created the managed transfer. If the -cs option was
  not specified, or was set to "MD5", then the source agent will
  reopen and re-read the file, generate an MD5 checksum and only
  delete the file if the checksum matches the original checksum
  that was generated when the file was transferred. If the -cs
  option is set to "none", then the source agent performs some
  basic validation, such as checking the file size and last
  modified date to see if it has changed.
  
  If the source agent is a protocol bridge agent, and the -cs
  option is set to "none", then the agent reconnects to the file
  server and then issues a LIST command to get the file attribute
  information. These attributes are then used for the basic
  validation checks.
  
  Prior to APAR IC98825, the protocol bridge agent used to perform
  the following processing if it was acting as the source agent
  for a managed transfer where the source disposition was set to
  "delete" and the -cs option was set to "none":
  
  - Reconnect to the file server.
  - Get the file attribute information for the source file.
  - Create an input stream for the source file, to open the file
  for reading.
  - Reread the source file.
  - Perform the basic validation checks, using file attribute
  information that was collected earlier.
  - Close the input stream for the source file.
  - Disconnect from the file server.
  
  Because the -cs option was set to "none", there was no need to
  re-read the source file and generate an MD5 checksum, as that
  checksum would never be used. As a result, APAR IC98825 changed
  the behaviour above to look like this:
  
  - Reconnect to the file server.
  - Get the file attribute information for the source file.
  - Create an input stream for the source file, to open the file
  for reading.
  - Perform the basic validation checks, using file attribute
  information that was collected earlier.
  - Close the input stream for the source file.
  - Disconnect from the file server.
  
  However, this caused an issue for certain file servers. When the
  input stream for the source file was created, a new data
  connection was established with the file server. Some file
  servers would then immediately start sending file data to the
  protocol bridge agent over the data connection.
  
  As a result of the code changes for IC98825, the time between
  the input stream being created and closed became much shorter
  than it used to be. As a result, the input stream was closed off
  while the file server was still sending data over the data
  connection. This caused the file server to return FTP reply code
  426 (Data connection error) back to the protocol bridge agent.
  The agent would receive this FTP Reply Code, and then generate
  the following warning:
  
  BFGSS0067W: The file has transferred successfully but the source
  agent was unable to delete the source file due to the following
  IOException:
  BFGBR0186E: The server has terminated the connection. The reply
  string sent back by the server was '426 Data connection error.
  

Problem conclusion

• As a result of this APAR, protocol bridge agents have been
  updated so that when they are processing a managed transfer that
  has the -sd option set to "delete", they will only create an
  input stream for the source file if the -cs option was either
  not specified or was set to "MD5".
  
  If the -cs option is set to "none", then the protocol bridge
  agent will behave in the following way when processing a source
  disposition of "delete":
  
  - Reconnect to the file server.
  - Get the file attribute information for the source file.
  - Perform the basic validation checks, using file attribute
  information that was collected earlier.
  - Disconnect from the file server.
  
  Because an input stream is not created, the file server does not
  use a data connection to send file data to the agent, which
  prevents the issue from occurring.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.0       7.0.4.6
  v7.5       7.5.0.7
  v8.0       8.0.0.5
  
  The latest available FTE maintenance can be obtained from
  'Fix List for WebSphere MQ File Transfer Edition 7.0'
  http://www-01.ibm.com/support/docview.wss?uid=swg27015313
  
  The latest available MQ 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 MFT V8.0

• Fixed component ID

  5724H7252

Applicable component levels

• R800 PSY

     UP