10 RabbitMQ Best Practices

RabbitMQ is a powerful message broker that can help you manage communication between applications and services. However, as with any tool, there are certain best practices that you should follow in order to get the most out of RabbitMQ.

In this article, we will discuss 10 of the most important RabbitMQ best practices. By following these best practices, you can ensure that your RabbitMQ implementation is efficient and effective.

1. Use durable queues

When you create a queue, by default it is not durable. This means that if the RabbitMQ server crashes or restarts, the queue will be lost. Any messages that were in the queue will be gone.

If you want to make sure your messages are persisted, you need to create a durable queue. To do this, simply set the durable flag to true when creating the queue.

Now, even if the RabbitMQ server crashes, the queue and its messages will still be there when the server comes back up.

2. Use persistent messages

If you don’t mark your messages as persistent, then RabbitMQ will store them in memory. This is fine if you’re just playing around or building a prototype. But if you’re building a production system, then you need to make sure that your messages are persisted to disk so that they’re not lost if the server crashes.

To do this, you need to set the message delivery mode to 2 when you publish your message. You can do this in the message properties:

properties.delivery_mode = 2

3. Use message acknowledgments

When a message is delivered to a consumer, RabbitMQ will mark it as “delivered” and remove it from the queue. However, if the consumer crashes before it has a chance to process the message, the message will be lost.

To prevent this from happening, you can use message acknowledgments. With this feature enabled, RabbitMQ will not remove a message from the queue until the consumer has explicitly acknowledged that it has received and processed the message.

If the consumer crashes before it has a chance to acknowledge the message, RabbitMQ will redeliver the message to another consumer. This ensures that messages are never lost, even if consumers crash.

4. Use publisher confirms

When you enable publisher confirms, RabbitMQ will keep track of messages that are sent but not yet acknowledged. This way, if there’s a problem with the message (for example, it goes to the wrong queue), you’ll know about it right away.

If you don’t use publisher confirms, there’s a risk that messages could be lost without you ever knowing. So if you’re not already using them, be sure to enable them in your RabbitMQ configuration.

5. Use the right exchange type

There are four different types of exchanges: direct, topic, header, and fanout. Each type of exchange has its own purpose and use case.

Using the wrong type of exchange can lead to messages being lost or not delivered to the correct queue. It can also cause performance issues.

For example, if you’re using a fanout exchange but you only have one queue bound to it, then all messages will go to that one queue regardless of whether or not it has any consumers. This can cause the queue to fill up very quickly and potentially crash your system.

Therefore, it’s important to understand the different types of exchanges and use the one that is most appropriate for your needs.

6. Avoid queue auto-delete

When a queue is created, it’s given a time-to-live (TTL) of 60 seconds. If no messages are consumed from the queue during that time, the queue will be automatically deleted. This is known as queue auto-delete.

While this may seem like a good way to keep your queues tidy, it can actually lead to some serious problems. For example, if you have a consumer that can’t keep up with the rate at which messages are being produced, the queue will be deleted before the consumer has a chance to catch up.

To avoid these sorts of problems, it’s best to disable queue auto-delete by setting the x-expires argument to 0 when creating the queue.

7. Use prefetching

Prefetching allows RabbitMQ to prefetch messages from a queue and deliver them to a consumer before the consumer has had a chance to process and acknowledge the previous message. This can be extremely helpful in increasing throughput, but it can also lead to problems if not used correctly.

If prefetching is turned on and set too high, it can lead to consumers processing more messages than they can handle, which can cause messages to be processed out of order or even lost.

It’s important to strike a balance when setting the prefetch count. You want to set it high enough to increase throughput, but low enough that you’re not overwhelming your consumers.

A good rule of thumb is to start with a prefetch count of 1 and gradually increase it until you start seeing issues.

8. Don’t use transactions

Transactions are slow. They involve multiple round-trips between the client and server, which adds latency and reduces throughput.

Transactions also consume extra resources on the broker, which can lead to performance problems when the system is under load.

If you absolutely must use transactions, make sure they’re as small as possible. Batch multiple operations into a single transaction if possible. And consider using the publisher confirms feature instead of transactions, which is more efficient.

9. Monitor your RabbitMQ server

RabbitMQ is a complex system, and things can go wrong. By monitoring your server, you can be alerted to issues as they happen and take action to fix them before they cause problems for your users.

There are many ways to monitor RabbitMQ, but one of the most popular is using the open source tooling provided by the team at CloudAMQP.

CloudAMQP provides tools for monitoring queues, messages, and consumers, as well as alerts and notifications if something goes wrong.

Monitoring is an essential part of any RabbitMQ deployment, and we recommend using the tools provided by CloudAMQP to make sure your RabbitMQ server is running smoothly.

10. Choose a client library that fits your needs

RabbitMQ is a very versatile message broker that can be used in a variety of scenarios. As such, there are many different client libraries available for it, each with its own strengths and weaknesses.

If you’re not careful, you can end up using a library that doesn’t support the features you need or that has poor performance. Therefore, it’s important to take the time to research the various options and choose the one that’s right for your project.