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

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