Reliability of return values
Return Values Regardless of the asynchronous option used, the return values of cache operations are reliable. If talking about return values of cache operations that return previous value, the correctness of these returns are guaranteed as well regardless of the clustering mode. With replication, the previous value is already available locally, and with distribution, regardless of whether it's asynchronous or synchronous, Infinispan sends a synchronous request to get the previous value if not present locally. If on the other hand the asynchronous API is used, client code needs to get hold of the NotifiyngFuture returned by the async operation in order to be able to query the previous value.