The Database Migration Debacle: Unraveling the Knot of Unexpected Performance Issues
It all began with what I thought would be a straightforward database migration — a routine task that turned into an unexpected odyssey through the intricacies of performance bottlenecks. After successfully migrating to a new managed database instance on Digital Ocean, my relief was short-lived as complaints about application performance began to surface. My initial instinct was to dismiss these as transient issues, hoping they’d resolve on their own — a classic first line of defense. However, the complaints persisted, prompting a more thorough investigation.
The symptoms were clear: excruciating slowness and frequent timeouts. The setup was theoretically identical to our previous environment: same database specs, same user configurations, and identical connection pools. Yet, the application performance was nowhere near what it had been. It dawned on me that the migration had introduced more changes than I had accounted for, including an upgrade from PostgreSQL 15 to 16 and the addition of a new load balancer — too many variables had changed simultaneously.
