[wildfly-dev] The EJB client and remote JTA transaction propagation

As you may know, WildFly supports a feature wherein an EJB client which is invoking an EJB on a remote server has the option to propagate its local transaction to the remote server, treating the remote server as a subordinate and coordinating the transaction's two-phase commit among the resultant graph of servers. This feature has always been limited in that, when enabled, transactions are always propagated, regardless of the peer EJB's transaction policy, or of whether the peer even has a transaction manager. So, for the invocation rework which I anticipate will be included in WildFly 11, I've introduced a new client-side annotation intended to be associated with the EJB interface which informs the client library what to do for transaction propagation for that interface. In addition, I intend to configuration strategies which will allow the default mode to be specified in various ways (per-thread, globally, and by target interface/method all come to mind), for cases where the EJB's remote interface cannot be easily modified for some reason. I expect to also broaden these configuration strategies to apply to all client-side EJB interface/methods configuration items [3]. The first part of this change is the addition of a new annotation called @ClientTransaction [1], which accepts as a value an enum called ClientTransactionPolicy [2]. The latter specifies whether a local transaction is required or forbidden for the method or interface, and also specifies whether the transaction is propagated or not propagated. I've added copious amounts of JavaDoc in order to establish exactly what the behavior of each mode is, as well as to specify how each mode interacts with the various modules that are configured via the standard javax.ejb.TransactionAttributeType enum. [1] https://github.com/jbossas/jboss-ejb-client/blob/master/src/main/java/org... [2] https://github.com/jbossas/jboss-ejb-client/blob/master/src/main/java/org... [2] (raw) https://raw.githubusercontent.com/jbossas/jboss-ejb-client/master/src/mai... [3] for a list, see: https://github.com/jbossas/jboss-ejb-client/tree/master/src/main/java/org... -- - DML