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Failover & Recovery Testing
Now the payoff: we kill the primary and watch the cluster heal itself with no human intervention....
Overview & Architecture
Redis ships with replication and a dedicated high-availability companion — Sentinel — but they ar...
Production Hardening & Troubleshooting
The build above is functionally HA. Before production, tighten these. Persistence — survive a ful...
Connecting Applications
This is the part that makes Sentinel different from a database-behind-a-proxy setup: the client d...
Sentinel — Automatic Failover Configuration
Replication gives us copies. Sentinel is what turns those copies into high availability — it watc...
Install Redis & Configure Replication
We install the same two packages on all three nodes, then point the two replicas at the primary. ...
Environment & Prerequisites
Servers You need three Linux servers (Ubuntu 24.04 LTS or 26.04 — Redis 8 and the redis-sentinel...
Failover & Recovery Testing
Now the payoff: we kill the primary and watch the cluster heal itself with no human intervention....
Overview & Architecture
PostgreSQL is famously reliable, but out of the box it has no built-in automatic failover. If the...
Production Hardening & Troubleshooting
The cluster we built is complete and self-healing, but a few choices were made to keep the lab to...
HAProxy — Connection Routing
Clients shouldn't connect to a specific database node — that node might be a replica today and go...
Bootstrapping the Cluster
With Patroni configured on all three nodes, we bring the cluster up. The order matters: the first...
PostgreSQL 18 & Patroni — Install & Configure
Run everything on this page on the three database nodes — pg-sv01, pg-sv02, pg-sv03. Install Post...
etcd — the Distributed Configuration Store
etcd is the distributed configuration store (DCS) that Patroni uses to elect a leader and hold cl...
Environment & Prerequisites
Servers You need four Linux servers (Ubuntu 24.04 LTS or 26.04 — this guide uses the PGDG reposit...
Assignment 2: Build a dashboard and a working alert
Goal: Get hands-on with Grafana on its own: connect to existing lab data, build a focused dashboa...
Assignment 1: CAPSTONE — Ship a full stack end to end
Goal: Prove you can take a real application all the way through the platform you've built across ...
Lesson: Loki, Mimir & Tempo
What you'll learn What Loki does for logs, and how to query it with LogQL. What Mimir does for m...
Lesson: The Collector
What you'll learn What a collector / agent does and why you need one between your systems and th...
Lesson: Dashboards, Exploring & Alerts
What you'll learn What a Grafana data source is and why Grafana stores no data itself. How to bu...