Chapter 18. Guarantees of sends and commits

When committing or rolling back a transaction with HornetQ, the request to commit or rollback is sent to the server. The call will be blocked on the client side until a response has been received from the server that the commit or rollback was executed.

When the commit or rollback is received on the server, it will be committed to the journal, and depending on the value of the parameter journal-sync-transactional the server will ensure that the commit or rollback is durably persisted to storage before sending the response back to the client. If this parameter has the value false then commit or rollback may not actually get persisted to storage until some time after the response has been sent to the client. In the event of server failure this may mean the commit or rollback never gets persisted to storage. The default value of this parameter is true so the client can be sure all transaction commits or rollbacks have been persisted to storage by the time the call to commit or rollback returns.

Setting this parameter to false can improve performance at the expense of some loss of transaction durability.

This parameter is set in <JBOSS_HOME>/jboss-as/server/<PROFILE>/deploy/hornetq/hornetq-configuration.xml.