Network Swiftlet (NIO and BIO): "dns-resolve-enabled" is now false by default because it takes sometimes 10 sec or more if the DNS name was not found. If you rely on host names (e.g. for host access lists), you must enable it explicitly.
JMS Swiftlet (standard and XA/ASF): Minimum size for router-input/output-buffer-size and client-input/output-buffer-size is now 4096 bytes.
Timer Swiftlet: Optimizations for large number of connections (= timers) (2500 and more).
Queue Manager Swiftlet: Message length is now calculated and shown in the SwiftMQ Explorer message viewer and CLI ("view" command).
Network Swiftlet (NIO and BIO): Receive buffer size will now be set before a socket is bound to a local address to ensure TCP receive buffer allocation greater than 64 KB.
JMS Client: Transparent reconnect with a durable subscriber to the same host may fail if the old connection is still active (half-open socket) because the client id is still in use. Instead of trying a new connect in the next interval the client reconnects with a random client id and creates a new durable subscriber.
JMS Client: The connection reader thread should be a non-daemon to ensure the application does not terminate.
JMS Client: Advanced Exception Handling: If a StoreException is thrown during a queue operation, it is thrown as a JMSException at the client instead of a QueueException.
Configuration compatible with previous releases: 4.5.0 (routerconfig.xml will be converted on the first startup)
Class compatible with previous releases: 5.1.0 (see release notes of release 5.1.0).