[OJB-developers] J2EE Persistence Manager

[Matthew B. <ma...@so...>]

I'm not sure the JTA J2EE persistence manager is implemented correctly (that
is PersistenceBrokerJ2EEImpl.java)

Is the assumption that the PersistenceBroker will participate in JTA
Transactions, but the Datasource will not? That's currently how it's
implemented. The PersistenceBrokerJ2EEImpl calls super.commit which goes
through connections and calls .commit, .begin, etc. In the appserver
environment, we're not supposed to do that.

On a related note, the PersistenceBrokerJ2EEImpl can never work given the
current architecture of OJB. Connections are cached and re-used via the
connection manager. In the J2EE environment, we should not cache
connections, as the app server hands us a connection and associates the
proper transaction with it (you aren't even getting a raw connection, just a
wrapper). We SHOULD, however cache the datasource we looked up. Then,
anywhere we use the connection, we should close it and "release' the
resources. it's not really going to release the resources, just let the app
server know you are done.

Also, give the current design, we'd never be able to make OJB work with XA
transactions.

Anyway, I've made these changes, but they are quite extensive (28 classes
changed, several added). I'm going to be testing over the next week, and
hopefully reduce the number of classes changed by making new implementations
that are pluggable.

For big changes like this, what is the protocol?

Whoever wrote the JTA peice, please contact me personally so we can work out
some issues.

cheers,
Matthew