异常后的Websphere MQ isConnected变量

Question

I use an C# Console Application to put and read messages of the MQ.. When the application starts, it connect once with the MQ and then the connection should be always upholded. The program runs every 30 sec and check if new messages are in the queue or a database(to put them on the queue) and check the isConnected-variable if its true.

• But what happen if an exception(2009 - connection broke) in the Put/Get occur? Will the isConnected automatically set to false?
• Is the connection automatically disconnected or do I have to call Disconnect() in the error handling?

Thanks!

Answer 1

To answer your exact question, for a basic .net application (non XMS) using MQQueue for put/get, if you get CERTAIN bad return codes from the underlying API call which indicates a connection issue, MQ will attempt an MQBACK and an MQDISC for you and will result in the connection handle being invalidated (IsConnected would return false) and an exception being thrown. However if an exception occurs outside those return codes then no attempt is made to do anything with the connection.

Basically you should not code an application relying on this behaviour, when the most simple answer is to always disconnect if you get an exception which relates to the quality of the connection or queue manager. For example, a no message available etc type exception doesnt mean you need to disconnect but a connection broken obviously does. There is no harm in calling disconnect on an already disconnected connection.