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  • 1.  Two-phase commit : experiences, guidelines, ... ?

    Posted Aug 21, 2017 07:50 AM

    In favour of  our CICS-applications accessing IDMS and MQ, we want to set up two-phase commit.

    Does anyone has done this in the past, and is willing to share some experiences and guidelines ?


    The topics I'm curious about are :

    • what are the "things" to think about ?
    • which are the CICSOPT settings used
    • Do I have to change both CICSOPT and IDMSCINT settings
    • do you need different CICS interfaces within the CICS region, when both two-phase commit and non-two-phase commit applications run in this region
    • what about the resynchronization transaction, is this mandatory ?
    • what todo in case of a failed two-phase commit
    • ....


    Thanks in advance.

    Best regards, Frank.

  • 2.  Re: Two-phase commit : experiences, guidelines, ... ?

    Posted Jan 30, 2018 09:50 AM

    We are not using IDMS in a Two-phase commit environment yet, but we are also asking the same questions. before I posted on the IDMS community, I searched and found this question.


    (Did you have any replies frank?)

    Has anyone made any progress on 2-phase commit?


    Does anyone want to discuss any Gotchas or issues or problems to look for?


    Several issues we are worried about are:

    How do we cater for DBA processes: Journal recovery, in flight backups, journal auditing?

    What happens when transactions are committed, but held "in-doubt".

    Does the transaction runtimes become extended?





  • 3.  Re: Two-phase commit : experiences, guidelines, ... ?

    Posted Jan 31, 2018 05:39 AM

    Hi Steve,


    Unfortunately I never got any replies on my questions, so I opened a case at CA support. Together with Yves Anthoons of CA, we did a lot of tests concerning parameter settings and their results.


    I suppose you're also going to setup an IDMS-CICS 2-phase commit ?


    In the meantime all is in place to have 2PC at our side, from an infrastructure point of view. CICS-Applciations will "soon" - the comming months - make use of two phase commit to commit the CICS UOW that accesses IDMS, MQ and/or DB2.


    I'm finalizing our own documentation about 2PC, containing the theory, but also how we did the setup, and some CICS information too . If I can/may, I'm willing to join this information with you.


    Best regards, Frank.

  • 4.  Re: Two-phase commit : experiences, guidelines, ... ?

    Posted Feb 02, 2018 06:35 AM

    Hi Frank,


    Thanks for your reply.


    We are currently looking at an external XA transaction manager to support our 2-phase-commit architecture using JDBC to update IDMS as part of a wider distributed transaction. But, when using CICS, I am thinking there will be similar considerations for existing IDMS systems.


    Any additional information would be useful.