Message Queue

What is Message Queue?

Message Queue provides Asynchronous communication between components. Which means the client sends the request and carry on with other work. It doesn't have to wait for the server to complete.

Message Queue is suitable for replacement for asynchronous communication. It Improves

• Performance
• Scalability
• Reliability 
• and more Resilience 

1. The client packages request as a message and send the message to the queue.

2. As soon as the queue has acknowledged the receive the message client can carry on the rest of the work

3. That message sits and waits on the queue until a handler picks it up.

4. The handler component picks up the next message in the queue.

5.  Once the handler did it confirms to the queue message complete so it gets removed from the queue. 

Message Queue Implementations

1. MSMQ - Message Queue System build in the Windows

2. ZeroMQ - Open source cross-platform message  queue

3. Cloud Message Queue (Azure Service Bus, AWS)

4. IBM WebSphere MQ

Key Patterns Receiving and Sendings Messages

1. Fire and Forget

2. Request and Response

3. Publish-Subscribe

Failed Processing of Messages

1. Retries

2. Poison Messages

3. Dead Letter Queue