Re: [bt-spec] When to garbage collect cohesions?

[Mark Little <mark_little@hp.com>]

PF: So it would primarily be a "no more enrols allowed" signal. 

Not an explicit signal, as I mentioned in the first email. A specific Qualifier that can go on prepare_inferiors and cancel_inferiors whose interpretation is "if by the end of this invocation the inferior list is empty then remove the transaction".

 

I agree the scenario is feasible, but since the only cost is the coordinator holding on to internal resources, or the message exchange to clear it, and it only makes a difference if the cohesion has emptied, I rather doubt if its worthwhile.The counterbalancing cost is in specifying, implementing, testing, explaining and documenting the feature.

I disagree that it is much extra cost at all. It is precisely this kind of optimisation that will be important in the take-up (if any) of BTP by traditional TP vendors. Your "only cost" is not necessarily an "only" when you talk to some of these people.

As always, non-standard control APIs could do more. Or a qualifier (std or not) on prepare_inferiors, cancel_inferiors (or even on request_inferiors_status, I guess)

 

 

As mentioned above, what we're after is a standard Qualifier that can do this. No extra message, very little extra overhead needed in explaining this to anyone, let alone adding text to the specification.

 

Mark.

 

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Dr. Mark Little, Distinguished Engineer,
Transactions Architect, HP Arjuna Labs
Email: mark_little@hp.com
Phone: +44 191 2606216
Fax  : +44 191 2606250