nick@tetrauk.UUCP (Nick Rumble) (03/26/91)
I am currently developing an OLTP product using standard TUXEDO /T & /D (4.1) and am looking for RDBMSs that can integrate into this environment. For RDBMSs to function as Resource Managers (RMs) within TUXEDO /T's applications environment, it is necessary for them to offer the suite of XA services defined by X/Open. I know that Informix and Unisys have co-developed an XA compliant version of OnLine. Does anyone know of any other RDBMSs that are currently or will soon be (next 12 months) XA compliant? Thanks in advance. Nick Rumble.
dhepner@hpcuhc.cup.hp.com (Dan Hepner) (04/02/91)
From: nick@tetrauk.UUCP (Nick Rumble) >Does anyone know of any other RDBMSs that are currently >or will soon be (next 12 months) XA compliant? If you're looking for plug-n-play, you're a bit early. There are three different definitions of what "XA compliant" means. 1. A de-facto standard set by Tuxedo/T 2. The Preliminary Specification of XA, published by X/Open 3. The Developer's Specification of XA, as yet unpublished by X/Open. They aren't all the same. It is unrealistic at this time to make too much of a claim that certain RM products are described as "XA compliant". The only real informational content is that certain TM-RM combinations, e.g. Tuxedo/T - Informix, are available. It's also quite possible to make use of Tuxedo/T - DBMS combinations which have no utilization of the XA interface at all. For newcomers, "XA" is a defined interface between "Transaction Managers", and "Resource Managers", whereby the TM and RM exchange information about global transactions, and implement a two phase commit protocol allowing atomic completion of such transactions over multiple machines / databases. Could you be encouraged to explain to us the class of problem for which you've found /T to be a valuable solution? Dan Hepner
nick@tetrauk.UUCP (Nick Rumble) (04/03/91)
In article <2060010@hpcuhc.cup.hp.com> Dan Hepner writes :- >The Developer's Specification of XA, as yet unpublished by > X/Open. In fact, the Developer's Specification of XA is now available through X/Open. Dan goes on to say :- >It's also quite possible to make use of Tuxedo/T - DBMS >combinations which have no utilization of the XA interface at all. True. But - and this is a *big* but, should one or more elements within a distributed TP application fail for some reason, remote transactions belonging to non-compliant DBMSs would remain in a pre-committed state. Having no control over them, the TP monitor could not instigate the necessary recovery (commit or abort) procedures, leaving the DTP application in an inconsistent state. Nick Rumble
bgolden@informix.com (Bernard Golden) (04/06/91)
In article <1125@tetrauk.UUCP> nick@tetrauk.UUCP (Nick Rumble) writes: > >In article <2060010@hpcuhc.cup.hp.com> Dan Hepner writes :- > >>The Developer's Specification of XA, as yet unpublished by >> X/Open. > >In fact, the Developer's Specification of XA is now available >through X/Open. > The Developer's Specification is not available yet. The Preliminary Specification was released in April 1990. The two are different. The Developer's Specification will incorporate comments made about the Preliminary Specification by various interested parties. The Developer's Specification should be out late this year. -b
dhepner@hpcuhc.cup.hp.com (Dan Hepner) (04/09/91)
From: nick@tetrauk.UUCP (Nick Rumble) >>The Developer's Specification of XA, as yet unpublished by >> X/Open. > >In fact, the Developer's Specification of XA is now available >through X/Open. From: bgolden@informix.com (Bernard Golden) >The Developer's Specification is not available yet. The Preliminary >Specification was released in April 1990. The two are different. The >Developer's Specification will incorporate comments made about the >Preliminary Specification by various interested parties. The Developer's >Specification should be out late this year. >> >>-b The direct workings of the XTP working group are "X/Open confidential", which means that detailed reports are made completely available to X/Open members and associate members. Both HP and Informix receive this information. Bernard and I are right, although no schedule has been publicly committed to. >>It's also quite possible to make use of Tuxedo/T - DBMS >>combinations which have no utilization of the XA interface at all. > >True. But - and this is a *big* but, should one or more elements >within a distributed TP application fail for some reason, remote >transactions belonging to non-compliant DBMSs would remain in a >pre-committed state. Having no control over them, the TP monitor >could not instigate the necessary recovery (commit or abort) >procedures, leaving the DTP application in an inconsistent state. > >Nick Rumble This big but presumes that the reason you are using Tuxedo/T is to do distributed transactions. Others have found usages in non-distributed environments. For example, it may be possible to put up a DMBS world which is much smaller than the number of actual users; the DBMS sees a small number of very busy users, as compared to a large number of relatively inactive users. This ends up being a real advantage for some configurations. Dan Hepner