Redis High Availability: Shared Sessions and Fault Tolerance
How to split Redis into isolated session, cache, and Sidekiq instances so a cache blip never logs users out or stops background jobs.
Tag: redis
Redis Cleanup and Memory Management in Kubernetes
A production-tested guide to keeping Redis healthy in Kubernetes: memory control, safe cleanup patterns, Sidekiq pitfalls, backups, and troubleshooting.
Rails 8.1.1 + connection_pool 3.x: RedisCacheStore boot crash
A keyword-argument mismatch between Ruby 3.4 and connection_pool 3.x breaks RedisCacheStore at Rails 8.1.1 boot, fixed with a patch loaded before initializers run.
From Shared Database to APIs: Taming the Performance Hit
How to cut the latency cost of moving from a shared database to an API-driven architecture, using caching, request aggregation, and async writes.
Managing Temporary Data in Multi-Step Rails Forms
Multi-step Rails forms need somewhere to hold data between steps, and this compares session storage, direct Redis caching, and temporary DB rows for that job.
Idempotent Rails Requests with a Redis Semaphore Lock
How to stop duplicate Rails requests from creating the same record twice, using a Redis-backed semaphore lock instead of chasing a race condition.
Redis Sentinel Split-Brain: Fixing It on Kubernetes
How Redis Sentinel split-brain happens during Kubernetes node maintenance, and the sentinel tuning, anti-affinity, and PDB changes that stopped it.
Handling Out-of-Order Updates in Async Rails Workflows
When async updates to the same record can finish in any order, the oldest write can silently overwrite the newest one; here is how to stop that.
API Design for Time Slot Replacement in Booking Systems
How to design a booking API that replaces regular time slots with alternatives, using server-side merging, cache versioning, and idempotency keys.
Upgrading Bitnami Redis Helm Charts Without Downtime
A runbook for upgrading Bitnami's Redis Helm chart in Kubernetes, covering node migration, debug dry runs, and a tested rollback plan.
Rufus-Scheduler vs Sidekiq-Scheduler for Ruby Jobs
Comparing rufus-scheduler's in-process polling loop with sidekiq-scheduler's Redis-backed queue to pick the right one for single-process vs distributed apps.
Redis Sentinel: How Automatic Failover Actually Works
How Redis Sentinel provides high availability: quorum-based monitoring, master election, automatic failover, and what your client applications must do to follow along.
Redis Memory Spikes: Tracking Down a Runaway Sidekiq Queue
How I traced a Redis memory jump from 130MB to 800MB back to an unthrottled Sidekiq integration, and the maxmemory, eviction, and unique-job fixes that followed.
Rails Session Stores: Cookie, ActiveRecord, and Redis
A comparison of Rails session stores: cookie sessions, ActiveRecord, and Redis, including how to share sessions across subdomains and multiple apps.
Fragment Caching a Large List That Changes Constantly
How splitting static and dynamic fields, granular fragment caching, and incremental loading keep a large, frequently updated list fast without stale data.
Redis in Ruby on Rails: Cache Server and Job Queue
Redis serves two very different roles in a Rails app, a disposable read cache and a durable job queue, and conflating the two causes real outages.