The Monday morning report: four hours of MySQL replica lag
Four hours of lag on a MySQL replica in a logistics system. How we diagnosed it, why Seconds_Behind_Master lies, and what actually fixed it.
Replication
6 tagged articles
MySQL
MySQL
The ticket said 'update MySQL and shut down the service'
A real MySQL 8.0.34→8.0.45 patching workflow: broken views blocking mysqldump, GTID warnings, replica role check, and RPM upgrade order on RHEL 8.
MySQL
Binary logs in MySQL: what they are, how to manage them, and when you can delete them
MySQL binary log: management, retention and point-in-time recovery. Real case of a server with disk at 95% and 180 GB of binlogs in six months.
MySQL
Galera Cluster with 3 nodes: how I solved a MySQL availability issue
3-node MySQL Galera Cluster for high availability: synchronous replication, quorum, SST/IST. Full configuration against single point of failure.
Oracle
From Single Instance to Data Guard: The Day the CEO Understood DR
Oracle Data Guard 19c: migration from single instance after a 6-hour outage. DR architecture, primary/standby, automatic switchover.
MySQL
Full disk on a MySQL cluster: binary logs, Group Replication, and a migration that leaves no room for mistakes
3-node MySQL Group Replication: migrating binary logs to a dedicated volume without losing quorum. Real case with filesystem at 92%.