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Are message queues synchronous?
Message queues implement an asynchronous communication pattern between two or more processes/threads whereby the sending and receiving party do not need to interact with the message queue at the same time. Messages placed onto the queue are stored until the recipient retrieves them.
Can a queue have multiple consumers?
Support for multiple-consumer queues is a Message Queue feature (the JMS specification defines messaging behavior in the case of only one consumer accessing a queue). When multiple consumers access a queue, the load-balancing among them takes into account each consumer’s capacity and message processing rate.
Can a queue have multiple consumers RabbitMQ?
RabbitMQ has a plugin for consistent hash exchange. Using that exchange, and one consumer per queue, we can achieve message order with multiple consumers. The hash exchange distributes routing keys among queues, instead of messages among queues. This means all messages with the same routing key will go the same queue.
What is asynchronous message queue?
A message queue provides an asynchronous communications protocol, which is a system that puts a message onto a message queue and does not require an immediate response to continuing processing. Email is probably the best example of asynchronous communication.
Can a message queue be used to lock messages?
We nearly reached the maximum capability of our database and would like to scale further. That’s why we’d like to implement this system with a message queue. However, message queues are not designed to lock messages for certain consumers on a certain field.
How does asynchronous communication with message queue work?
In sync approach, as soon is user hits “Place Order” button, UI-service would invoke AddOrder method at fulfillment-service side. In async approach, UI-service would publish the message “OrderPlaced, here’s the data. Whatever…” and immediately stopped caring. But we need somewhere to publish messages to and that somewhere is Message Queue.
What happens when a message is locked in azure?
When a message is locked, other clients receiving from the same queue or subscription can take on locks and retrieve the next available messages not under active lock. When the lock on a message is explicitly released or when the lock expires, the message pops back up at or near the front of the retrieval order for redelivery.
Do you need two message queues in MQ?
We also will need two message queues: one for publishing the message, and one for incoming responses. Publish-subscribe. We also can have more than one receiver of a message, and it’s very interesting how MQ makes that possible. Every subscriber will have its own message queue.