Content Hub

Rails 8 Solid Stack: When to Remove Redis

Guides for deciding which Rails 8 defaults to adopt: Solid Queue, Solid Cache, Kamal, the built-in authentication generator, and Hotwire. Removing Redis is a good outcome only when Redis was not carrying queue latency, locks, pub/sub, rate limiting, or a hot cache path the database cannot absorb.

REDIS ONLY RUNS JOBS

Start with the Sidekiq migration runbook. Inventory queues, retries, scheduled jobs, and pickup-latency requirements before changing the adapter.

REDIS IS THE CACHE

Read the Solid Cache guide only after checking database headroom, cache churn, write amplification, and eviction behavior.

REDIS POWERS COORDINATION

Keep Redis when it provides pub/sub, distributed locks, rate limiting, or Sidekiq Pro and Enterprise features. Rails defaults do not replace those one-for-one.

DEPLOYS ARE THE PAIN

Start with Kamal and rollback checks. A queue migration will not fix missing health checks, migration sequencing, or weak deploy visibility.

Do Not Remove Redis When...

  • Sidekiq Pro or Enterprise features are part of the product contract: batches, reliable fetch, unique jobs, or rate limiting.
  • The app depends on Redis pub/sub, distributed locks, counters, or request-time rate limits outside Action Cable.
  • Queue pickup latency needs to stay in the low-millisecond range under burst load.
  • The cache is write-heavy and moving churn into PostgreSQL would compete with the primary application workload.
  • The team already operates Redis well and the real failure mode is deploy sequencing, missing observability, or unclear ownership.

Planning a Rails 8 migration?

Before touching an adapter, the first move is mapping which Redis features are load-bearing: queue latency, distributed locks, pub/sub, rate limiting, or a hot cache path Postgres cannot absorb. That map, together with your deploy rollback path, decides which Solid Stack pieces are safe to move first and which Redis-backed parts should stay put. When the goal is latency and cost rather than removing Redis, the Rails performance hub is the better starting point.

View Rails consulting services