OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help

bt-spec message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [Elist Home]

Subject: Re: [bt-spec] BTP Issue 53 : will or may contradict ?

Yes, assuming the CONFIRMs are sent out synchronously, waiting for the replies. That's not necessarily a good idea - if the first is slow to respond, the others have to hang on waiting to know the otucome. That might be ok in a closed environment, but would seem to be more iffy in the "more loosely coupled" environment we expect for BTP.
"may" makes the statement rather too weak - it really is a very special case that an wrong autonomous decision doesn't produce a contradiction.
Suggestion: just add "usually" in "latter will usually cause a CONTRADICTION"
We should not be assuming anything about the environment in which BTP will "typically" be used. As a result, it's not an objective statement to say it's a "very special case", since that in itself is based on certain assumptions about deployment. I don't mind "usually", but what I do want is some text along the lines of:
"If the coordinator is issuing the second phase of a successful (i.e., CONFIRM) completion protocol synchronously, then it is possible upon the receipt of a CANCEL message from the first non-RESIGNED participant for the coordinator to change it's decision to CANCEL the atom, and in such a way prevent a CONTRADICTION from occurring. Otherwise ..."
I would like to avoid contradictions as much as possible, because cleaning up after them is going to be a nightmare for system administrators, especially if they are spread across the planet. It's exactly the same argument as for this kind of optimisation in TPs with heuristics.
Dr. Mark Little
Transactions Architect, HP Arjuna Labs
Email: mark@arjuna.com | mark_little@hp.com
Phone: +44 191 2064538
Fax  : +44 191 2064203

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [Elist Home]

Powered by eList eXpress LLC