Redis
Redis is an open-source, in-memory data structure store that is used as a database, cache, and message broker. In Mastodon, Redis is used for various purposes to improve the performance, scalability, and reliability of the platform.
We use the DigitalOcean managed Redis database service, this delivers a highly available database backend. Our primary Redis service has 2 vCPU and 4GB of memory running Redis 7.x.
Our connection to Redis is configured as a REDIS_URL
variable using a connection string.
REDIS_URL=rediss://default:password@redis.db.ondigitalocean.com:25061
Note that the second s
in rediss
is not a typo and is used for TLS connections only.
Standard deployments of Mastodon currently cannot use this connection type, due to limitations of the hiredis
driver.
We disable hiredis
in our implementation.