Two phase commit

Pandora-Box · Posted: Sun Mar 25, 2012 9:35 pm

Hi all,

I have three programs A,B,C

A ==> Main driver cics program which links B and calls C dynamically
B ==> CICS program which process data in tables
C ==> MQ routine which would be called for every MQ operation ( open,put,close)

Now the major driver CICS program A does some process and links B and inserts some records to tables

The program B actually does "EXEC CICS SYNCPOINT END-EXEC" if SQLCODE of table process is 0

So My table has data like

dbzTHEdinosauer · Posted: Sun Mar 25, 2012 11:03 pm

you should have the logic to do a syncpoint or rollback in the same place.

keep in mind, the idea of RRSAF
(where you have more than one resource,
in this case DB2 and MQS)
you want a 'commit' or 'rollback' decision based on 'unit of work'.

if the MQS write is based on a successful completion of DB2 process,
you should do the sycnpoint after the MQS write
and not
afer the DB2 process
otherwise, you have divided a unit-of-work, which you should not do.

now, as to your question about what is or is not there after commit and rollback,
insure that you are using RRSAF.

if you are not using RRSAF, then that is another conversation, for another time.

as to why you are performing what should be a batch process in cics,
let the fact that i made the comment suffice as a negative critique.

and last but not least, forget the fact that you have 3 programs,
IT IS ONE TASK,
and work is accomplished in a task, and not a program.
if it helps,
just think as the linked-to and CALLed program as just two more paragraphs within the mainmodule.

Pandora-Box · Posted: Sun Mar 25, 2012 11:22 pm

Yes Dick

Thanks I understand your point but say there is a requirement that I need to inform certain users that MQ has been failed due to some reason may be like when MQs are down after DB2 process

Yes I do agree with you I need to consider things "1 Unit of work"

How to acheieve that??

dbzTHEdinosauer · Posted: Mon Mar 26, 2012 1:11 am

you never answered my question about RRSAF.
the 1 unit of work decision is based on your answer to that.
Do you have it installed and implemented?

as far as as informing users that something is not available,
i prefer to notify those who are responsible for insuring that a service is available.
as to notifying the user, how are you communicating with them now?

i have no idea about what your process actually does.
is it screen driven by a user, where you have essentially one transaction?

Pandora-Box · Posted: Mon Mar 26, 2012 7:49 am

Yes RRSAF is installed nd yeah one unit of work gets done after writing to MQ

No its,not a screen but a web page which calls A

dbzTHEdinosauer · Posted: Mon Mar 26, 2012 4:07 pm

if the unit of work is complete when mqs is written,
then that is when the syncpoint should be taken either commit or rollback.

when then webpage invokes cics transaction,
how many db2 processes and mqs processes are expected for each invocation?

This thread:
ibmmainframes.com/about55525.html
last two post are of interest.

Pandora-Box · Posted: Tue Mar 27, 2012 12:24 am

Yes RRSAF is installed nd yeah one unit of work gets done after writing to MQ

No its,not a screen but a web page which calls A

dick scherrer · Posted: Wed Mar 28, 2012 3:19 am

Hello,

Was there some reason to re-post your previous reply?

I suspect it would have been more productive to answer the question from DBZ as well as comment on the link provided. . .

d

Pandora-Box · Posted: Wed Mar 28, 2012 10:02 am

Oops Apologies my mistake I guess I am in need of break badly I never know why I replied that

For each webpage invocation. I process webpage atleast three times and write to MQ just once

I did see that link long back when the other Dick