Scaling the GitLab database. Lots of interesting details on how GitLab have worked to scale their PostgreSQL setup. They’ve avoided sharding so far, instead opting for database pooling with pgbouncer and read-only replicas using hot standbys. I like the way they deal with replica lag—they store the current WAL position in a redis key for the user every time there’s a write, then use pg_last_xlog_replay_location() on the various replicas to check and see if they have caught up next time the user makes a request that needs to read some data.
Recent articles
- OpenAI DevDay: Let’s build developer tools, not digital God - 2nd October 2024
- OpenAI DevDay 2024 live blog - 1st October 2024
- Weeknotes: Three podcasts, two trips and a new plugin system - 30th September 2024