The way transactions are handled depends on the nature of incoming request and the transaction characteristics of the partner service.
If the incoming binding for the request to OSB is transactional then the proxy will participate in that txn and any proxy/business svc invoked by this proxy will participate in the same txn.
The control of this transaction will be with the client.
If the service inturn invokes several transactional proxies/business svc’s they will be all enrolled in the intial inbound txn and committed together or rolled back together.
Non Transactional Binding
while if the incoming binding for req is non transactional eg SOAP or file transport then the txn behaviour will depend on type of proxy.
There is a difference between types of proxies available in OSB 11g than the previous versions.
Non-Transational proxy (default type and the only type that existed prior to 11g)
Unless there are incoming transactions, the proxy will not execute as part of a transaction.
Any subsequent transactional services it invokes will each execute in their own txn.
i.e. they will not necessarily be all complete or roll back together. some may succeed while others may not.
Transational proxy (A new feature in 11g)
It will initiate a new txn if one does exist in the req recieved, and there on all calls are part of the same txn, hence all commit or roll back together.