These are your favorite GitLab engineering stories

This post details the execution and lessons learned from several major infrastructure migrations and debugging efforts at GitLab. It covers the migration of GitLab.com from Azure to GCP, including performance improvements post-migration. It also describes the upgrade of a major PostgreSQL cluster, highlighting the planning, testing, and automation involved. The migration of GitLab.com to Kubernetes is discussed, along with the challenges and triumphs experienced in the year following the migration. The post also details debugging efforts for a Docker client library bug, an NFS bug impacting the Linux kernel, and a scaling problem on GitLab.com related to clock synchronization. Finally, it touches on the migration from legacy NFS to Gitaly, including performance diagnosis and fixes, and the use of Prometheus for anomaly detection and alerting.