Re: [jbosscache-dev] JBoss Cache weakness handling heuristic transaction outcomes - [Fwd: [Fwd: New case comment notification. Case Number 00017677]]

No - by purge, I mean remove all affected nodes from the cache, thereby assuming that the cache is backed by a DB and will be populated again.

On 21 Aug 2007, at 16:10, Galder Zamarreno wrote: > > > Manik Surtani wrote: >> On 21 Aug 2007, at 15:44, Jonathan Halliday wrote: >>> Manik Surtani wrote: >>>> Sorry about the slow response on this. >>>> While making JBC an XA resource is on the roadmap, it isn't >>>> something scheduled for any imminent release [1], as this is a >>>> pretty big change for the JBC codebase (and more importantly, a big >>>> feature change which would involve a lot of compatibility testing). >>>> For the time being, treating STATUS_UNKNOWN as a rollback would >>>> help, but only provided the database (and any other resources >>>> participating in the tx) has rolled back as well. Jonathan, >>>> correct me if I am wrong, but there is no way to know this unless >>>> we are an XA resource as well, am I right? >>> >>> Actually in heuristic outcomes you still won't necessarily know what >>> the db did. The transaction manger will tell you what it decided, >>> but not what each individual resource actually did. For that you >>> would need JBossTS specific code rather than general XAResource >>> code. You can partially address that by making the cache the last >>> resource but you won't eliminate it entirely. >>> >>>> So is it reasonable to treat a STATUS_UNKNOWN as a rollback, and >>>> document this limitation, until JBCACHE-70? >>> >>> yes, or toss anything that is affected out of the cache and let it >>> be reread from the db on the next tx, which would prevent you ever >>> getting out of sync. Or course that assumes the data is backed by >>> some store e.g. the db, which is the case only for EJBs. General >>> purpose use of the cache is a more difficult case. >> Perhaps a switch for this behaviour? By default, do a rollback, >> unless -Dorg.jboss.cache.tx.heuristic_outcome_purge = true? > > By purge, you mean? > - rollback modifications > - and commit the tx > >> What do you guys think? >> Cheers, >> -- >> Manik Surtani >> Lead, JBoss Cache >> JBoss, a division of Red Hat > > -- > Galder Zamarreño > Sr. Software Maintenance Engineer > JBoss, a division of Red Hat -- Manik Surtani Lead, JBoss Cache JBoss, a division of Red Hat