Spotify replaced its in-house TSDB (Heroic) with VictoriaMetrics and Prometheus, achieving 10x faster query speeds and significant cost savings. The 2 year migration addressed stability, performance, and stakeholder dissatisfaction with Heroic's slow queries and bespoke nature. After evaluating alternatives, VictoriaMetrics was chosen for its speed, cost efficiency, Prometheus compatibility, and self-hosted flexibility. Challenges included migrating from Heroic's overly flexible data model and often misused HQL to Prometheus's standardized structure and best-practice PromQL, a necessary shift for improved data quality and query efficiency. The migration involved updating metric agents, adapting alert management, and a significant fleetshift. Benefits included improved dashboard loading times, faster alerting, more accurate data, and alignment with industry standards.
