Redis Pub/Sub vs Rabbit MQ

Question

My team wants to move to microservices architecture. Currently we are using Redis Pub/Sub as message broker for some legacy parts of our system. My colleagues think that it is naturally to continue use redis as service bus as they don't want spend their time on studying new product. But in my opinion RabbitMQ (especially with MassTransit) is a better approach for microservices. Could you please compare Redis Pub/Sub with Rabbit MQ and give me some arguments for Rabbit?

Militarist

You might want to show this twitter.com/tastapod/status/1010462778207981569 to your colleagues, Dan North about the "best programmer I know". – Showing

Answer 1

Redis is a fast in-memory key-value store with optional persistence. The pub/sub feature of Redis is a marginal case for Redis as a product.

RabbitMQ is the message broker that does nothing else. It is optimized for reliable delivery of messages, both in command style (send to an endpoint exchange/queue) and publish-subscribe. RabbitMQ also includes the management plugin that delivers a helpful API to monitor the broker status, check the queues and so on.

Dealing with Redis pub/sub on a low level of Redis client can be a very painful experience. You could use a library like ServiceStack that has a higher level abstraction to make it more manageable.

However, MassTransit adds a lot of value compared to raw messaging over RMQ. As soon as you start doing stuff for real, no matter what transport you decide to use, you will hit typical issues that are associated with messaging like handling replies, scheduling, long-running processes, re-delivery, dead-letter queues, and poison queues. MassTransit does it all for you. Neither Redis or RMQ client would deliver any of those. If your team wants to spend time dealing with those concerns in their own code - that's more like reinventing the wheel. Using the argument of "not willing to learn a new product" in this context sounds a bit weird, since, instead of delivering value for the product, developers want to spend their time dealing with infrastructure concerns.

Showing

Answer 2

RabbitMQ is far more stable and robust than Redis for passing messages.

RabbitMQ is able to hold and store a message if there is no consumer for it (e.g. your listener crashed , etc).

RabbitMQ has different methods for communication: Pub/Sub , Queue. That you can use for load balancing , etc

Redis is convenient for simple cases. If you can afford losing a message and you don't need queues then I think Redis is also a good option. If you however can not afford losing a message then Redis is not a good option.

Stereotaxis

Thanks a lot! What do you mean by "RabbitMQ is far more stable and robust"? – Sardinian

RabbitMQ supports persistent messages and transient messages. When it sends messages to the persistent queue, it writes data to permanent storage as soon as it arrives. RabbitMQ also writes transient messages to the disk, but only if they exceed the memory’s capacity. Redis does not support persistent messages by default. Developers must enable a feature called Redis Database (RDB) to take periodic snapshots of the RAM and store them on disk. Enabling data persistence on Redis adds overhead to data operations, which slows down message delivery. – Twila

Answer 3

I guess it depends on needs. I use mostly rabbitmq, but I have a task...

I have a list of users to connect by socket and listen to data all of them. It is managed by a single script with an infinite loop. I want to connect to all of them on startup. I want to make a new connection on inserting new items and disconnecting if the item was removed.

If the script fails, I want to restart it with reconnecting all users

So... if I use just a rabbitmq, I have to store a list of users somewhere separately

Dulcia