Graceful Server Shutdown

In certain circumstances an administrator might not want to disconnect all clients immediately when stopping the broker. In this situation the broker can be configured to shutdown gracefully using the graceful-shutdown-enabled boolean configuration parameter.

When the graceful-shutdown-enabled configuration parameter is true and the broker is shutdown it will first prevent any additional clients from connecting and then it will wait for any existing connections to be terminated by the client before completing the shutdown process. The default value is false.

Of course, it's possible a client could keep a connection to the broker indefinitely effectively preventing the broker from shutting down gracefully. To deal with this of situation the graceful-shutdown-timeout configuration parameter is available. This tells the broker (in milliseconds) how long to wait for all clients to disconnect before forcefully disconnecting the clients and proceeding with the shutdown process. The default value is -1 which means the broker will wait indefinitely for clients to disconnect.