[infinispan-dev] commit not failing but transaction reported as in-doubt

[Jonathan Halliday]

No, it's out of scope for the TM, at least as far as the JTA/XA specs 
are concerned. The TM would not retain any txlog information to allow it 
to perform useful recovery anyhow.   Usually you just log it in the hope 
a human notices and sorts out the mess.  Of course properly paranoid 
humans don't use async commit in the first place.

There has been various talk around making JTA TM.commit() support an 
async callback, such that the business logic thread can continue as soon 
as the prepare phase is successful, whilst still receiving a callback 
handler invocation if the commit phase subsequently fails. Extending 
that to the XA protocol would be nice, but won't happen as there is no 
upward (RM->TM) communication in XA - it's all driven top down.  So as 
you point out, adding the failed tx to the in-doubt list is the only way 
of signalling a problem. That's bad, since you'd also need a positive 
'it worked' callback in the proto to allow GC of the txlog, otherwise 
you have to throw away the log eagerly and can't then do anything useful 
with the subsequent error callback anyhow.

Associated with that discussion is the expectation around the semantics 
of afterCompletion, which may mean 'after successful prepare' or 'after 
successful commit' in such case, the latter effectively removing the 
need for a new JTA callback api in the first place.

If you don't need a callback at all, then there is already an async 
commit option in the TM config, it's just non-standard and marginally 
dangerous. It simply logs commit phase failures and hopes a human notices.

Jonathan.

On 05/15/2013 01:13 PM, Mircea Markus wrote:
> Hi Jonathan,
>
> In the scope of ISPN-3063 [1] we came to a problem we need some advice on :-)
>
> Would a transaction manager expect/handle this situation: for a transaction the commit is successful but at a further point the same transaction would be reported as "in-doubt" to the recovery process. In our case this can happen when we send the commit async and this might only fail after the commit is acknowledged to the TM.
>
> [1] https://issues.jboss.org/browse/ISPN-3063
>
> Cheers,
>

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