6.6. Transactional Behavior with JBoss Data Source Types

xa-datasource: Capable of participating in the distributed transaction using XA. This is the recommended type be used with any JBoss Data Virtualization sources.

local-datasource: Does not participate in XA, unless this is the only local-datasource participating among other xa-datasources in the current distributed transaction. This technique is called last commit optimization. However, if you have more than one local datasource participating in a transaction, the transaction manager will throw an exception: "Could not enlist in transaction on entering meta-aware object!".

no-tx-datasource: Does not participate in distributed transaction at all. In the scope of a JBoss Data Virtualization command over multiple sources, you can include this type of datasource in the same distributed transaction context, however this source will not be subject to any transactional participation. Any changes done on this source as part of the transaction scope, cannot be rolled back.

A-xa B-xa, C-xa : Can participate in all transactional scopes. No restrictions.

A-xa, B-xa, c-local: Can participate in all transactional scopes. Note that there is only one single source, "local". It is assumed that, in the Global scope, any third party datasource other than JBoss Data Virtualization datasource is also XA.

A-xa, B-xa, C-no-tx : Can participate in all transactional scopes. Note "C" is not bound by any transactional contract. A and B are the only participants in the XA transaction.

A-xa, B-local, C-no-tx : Can participate in all transactional scopes. Note "C" is not bound by any transactional contract, and there is only a single "local" source.

If any two or more sources are "local" : They can only participate in Command mode with "autoCommitTxn=OFF". Otherwise they will end with an exception and the message "Could not enlist in transaction on entering meta-aware object!;" because it is not possible to do a XA transaction with "local" datasources.

A-no-tx, B-no-tx, C-no-tx : Can participate in all transaction scopes, but none of the sources will be bound by transactional terms. This is equivalent to not using transactions or setting Command mode with "autoCommitTxn=OFF".

Use XA datasource if possible

Use no-tx datasource if applicable

Use autoCommitTxn = OFF, and let go distributed transactions, though not recommended

Write a compensating XA based implementation.