Troubleshooting Link3270 server adapters

If you are experiencing a problem with a Link3270 server adapter, read through the following information to find out how to diagnose the problem.

About this task

The Link3270 server adapter enables a service requester to access 3270 application programs that are running in CICS using the CICS Link3270 bridge mechanism. If you receive an error message in the range DFHMA07001E to DFHMA07999E, or unexpected or incorrect data is being returned when you invoke the service flow, you must capture diagnostic information using the provided utilities and troubleshooting aids. Follow the steps below to collect the necessary information and analyze it to find the cause of the error.

Procedure

  1. Check the CICS job log for any recent error messages.
    For example, if you see a DFHBR0501 error message, the Link3270 server adapter has failed because the Link3270 bridge file DFHBRNSF is not defined in your CICS region. This file is required to run any Link3270 server adapter.
  2. If there are any DFHMA-prefixed error messages, check the error information provided with the message to give you an indicator of what went wrong.
    1. Look up the values for the CICS RESP and RESP2 fields in Reference: application development.
      The RESP and RESP2 codes will give you a good idea of why there was a failure.
    2. If the error occurred in a Link3270 server adapter, the end of the error message displays the inbound and outbound Link3270 bridge message field values.
  3. If you receive a DFHMA02002E error message for a complex Link3270 service flow, ensure that the SERVICE NAME field in the generation properties of service flow project tools is set to the same value for each Link3270 bridge node.
    CICS SFR uses this field to carry status information about the server adapters. If the field is omitted, it can cause this error.
  4. If you need to capture additional information, enable vector logging for your server adapter using the CMAN transaction.
    1. Enter CMAN in the display.
      Browse the list to find the service flow that is causing the error.
    2. Press 1 to view the service flow details.
    3. Enter 2 next to the appropriate Link3270 server adapter to switch on vector logging.
  5. Invoke the service flow to capture the flow of data through the Link3270 server adapter.
    CICS SFR updates the vector log file during request processing.
  6. Dump the vector log file using the provided sample JCL.
    1. Check that the sample module DFHMAVUP is located in the hlq.SCIZSAMP library and has been compiled.
    2. Run the sample JCL job DFHMAMVD.
      This runs the vector log dump utility DFHMAVUP. See Link3270 Vector Log file dump JCL, DFHMAMVD to view the sample JCL.
  7. Analyze the vector log file dump.
    See Analyzing the vector log file dump for what information to look for in the dump.