Notes

Short write-ups from backend work: things that took me an afternoon to figure out and should take the next person five minutes.

• 2026-10-19#spring
  Graceful shutdown for Spring Boot on Kubernetes

  Three settings that stop rolling deploys from dropping requests.

• 2026-09-02#postgres
  Adding an index to a busy PostgreSQL table

  CREATE INDEX CONCURRENTLY, the invalid-index trap, and how to run it from a migration.

• 2026-07-14#kafka
  An idempotent Kafka consumer with one extra table

  At-least-once delivery means duplicates. A unique key in the same transaction handles them.

• 2026-05-27#postgres
  Where the database time goes: pg_stat_statements

  One extension and one query that answer most 'the database is slow' tickets.

• 2026-03-11#docker
  Layered Docker images for Spring Boot

  Split the fat jar into layers so a code change pushes kilobytes, not the whole image.

• 2026-02-03#ci
  Maven cache in GitLab CI that actually hits

  Move the local repository inside the project directory and key the cache on pom.xml.

• 2026-01-12#kubernetes
  kubectl commands I keep forgetting

  A short list for the moments when something is wrong and the dashboard is not helping.