Close RabbitMQ connection even if application does not end gracefully

Question

I use RabbitMQ.Client (runtime version v2.0.50727, version 2.8.1.0) with C# .NET application.

I create connection like this:

using (IConnection connection = _factory.CreateConnection())
{
    using (IModel channel = connection.CreateModel())
    {
        // code...
    }
}

If I close the application properly, it simply closes the channel and connection. But if application is closed incorrectly (e.g. pressing restart button on PC), it is not. I would like to ensure that all unnecessary connections (from previous sessions or even other applications, if by mistake other instance of the application is running somewhere else) are closed before I start my application.

I know I may use heart beats but it is possible that my application requires really much time to start doing anything (many hours of opened connection and not being used). So I think heartbeat is not the best thing.

How can I close all opened connections for RMQ? (Or, even better, all opened connections, with the exception for one given IP)?

Regards!

Answer 1

I encountered the same problem as you. I tried a lot of methods to close those connections.

Those methods, some are works some are only part works. Maybe you can have a try.

1. Use rabbitmqctl command to delete the queues then use RMQ's management website close the connections. It means current opened queues will expire after 1 second(1000 miliseconds). This way all queues are deleted. Then you can close connections.

   Command:

   rabbitmqctl set_policy expiry ".*" '{"expires":1000}' --apply-to queues

   Queue Time-To-Live policy--> https://www.rabbitmq.com/ttl.html

   This method works partly.

2. After searching, got the idea that reason might be:

   Your producer waiting the return ACK back, it won't be destroyed untill you send ACK to acknowledge the job has finished.

3. Abrupt way. Works. RMQ save connections information in its DB menisa.

   Step1: Stop rabbitmq-server first, and kill rabbitmq thread by 'ps aux | grep rabbitmq' to find its pid then kill all rabbitmq thread.

   Find RMQ DB mensia location (1). $> cd /var/lib/rabbitmq/

   Step2: rename mensia file to another name to "delete" (2). $> mv mensia mensia-bak

   Step3: restart rabbitmq-server

   The third methods works for me now. It can close all open connections.

Answer 2

Sounds like Heartbeats is your best solution. I added heartbeats to my RabbitMQ apps for the same reason (ungraceful shutdowns). It shouldn't matter that there is a long gap of time between messages, heartbeat will just verify that the connection is still open on both sides.