Re: X/Open XA Interface

Trevor Inns wrote:
>
> If I want to write an X/Open compliant Transaction Monitor (TM) how does it
> communicate with Oracle's XA Interface? Is the XA library linked with the
> TM as part of the TM process (i.e. Oracle's XA Interface is responsible for
> the communication messages to the Oracle RDBMS) OR is the XA library part
> of the Oracle RM process (i.e. the TM is responsible for communicating
> between the TM and RM processes)?
>
> Thanks
>
> Trevor Inns

My experience with building an X/Open XA compliant Transaction Monitor is with the Tuxedo product. Under Tuxedo, you build a TM executable using the 'buildtms' command. You do need to link the Oracle XA library with the TM process, as well as various other Oracle libraries and tuxedo libraries (in this case). You will probably also need to specify a resouce manager name and structure at the link stage.

At runtime, you should start the TM process as a server under your TP monitor with the appropriate startup parameters. It will then be able to control distributed transactions. As I understand it, the RM part of the deal is handled by Oracle library calls performed by your application server. (ie: there is no separate RM process as such - unless you consider the database instance to be it.)

The client will then be responsible for sending requests to start, commit, rollback transactions to the TM process. Your application server(s) will attach to a distributed session at startup. The servers will perform database operations (select, insert, delete etc.), but will not be responsible for commits or rollbacks.

Information regarding XA requirements (link requirements, startup parameters etc.) is provided in the Oracle documentation (albeit in a fairly lean form - usually a couple of pages giving the bare minimum of information necessary, submerged in the back of a manual somewhere). Also, the TP monitor you are using should provide information on how to build an XA compliant TM.

Hope this helps,

        Mike

-- 
Mike Biggin
DENR, South Australian Government
E-mail: mbiggin_at_denr.sa.gov.au
Phone: +61 8 8204 9217; Fax: +61 8 8204 9017

Unless explicitly attributed, the opinions expressed are personal
and not those of DENR or the South Australian Government.