How to use Redis as a cache instead of Caffeine?

[dewan-ahmed]

I'm trying to build an app using Quarkus and Redis as the cache. I'm following two guides:

1. Application Data Caching guide which uses Caffeine as the cache, and
2. Redis client guide which uses Redis increment/decrement functionality.

Could someone please point out how I can use Redis as the cache instead of the underlying Caffeine caching mechanism?

My work-in-progress code

This is my assumption of what needs to happen (I don't know the 'how'):

1. I'll have to have a Redis server - either locally via Docker or some managed Redis service. I'll need to enter the Redis server details in the application.properties file.
2. I'll need to use a Redis client like Redisson and add a dependency under pom.xml. Then I need to create an instance of that caching service and tell that caching service to use the Redis service I entered in the application.properties file.
3. Similar to the WIP code I have, this is the only place where I'll need to swap the caching mechanism.

I tried to follow this guide but couldn't make much progress. Please let me know any guide/resource I can follow and if my above assumptions are correct. Thanks.

[quarkus-bot[bot]]

/cc @cescoffier, @gsmet, @gwenneg, @machi1990

[dewan-ahmed]

quarkus-cache was designed to support multiple caching providers, but local caching with Caffeine is the only available option for now. Using another provider would require changes in the extension code so it's not pluggable indeed.

Hi @gwenneg could you please point me to a doc/guide on how I can use quarkus-cache with an external Redis caching provider? I tried to search the Quarkus docs but couldn't find much details.

[karesti]

I'm working on having the annotations in the infinispan client extension ATM :)

[dewan-ahmed]

That's great @karesti

When implemented, would the infinispan client use the underlying Caffeine cache + Infinispan distributed cache, Or, the Quarkus app will directly use the Infinispan distributed cache?

[gwenneg]

As I wrote earlier, the quarkus-cache extension only supports local caching with Caffeine right now. From a Quarkus user perspective, there is no way to use Redis as the caching provider with that extension. This could change in a future Quarkus release though if someone contributes to the extension and adds a Redis caching provider.

quarkus-infinispan-client which was mentioned by @karesti is a different extension that offers distributed caching. It is based on Infinispan and does not have anything to do with Redis AFAIK, but I'm not an expert about this extension.

If you really want to use Redis, then quarkus-redis-client may be the only available solution right now. It won't work with the annotations from quarkus-cache.

[gsmet]

There is now a quarkus-redis-cache extension that does exactly what you wanted: https://quarkus.io/guides/cache-redis-reference .