Are your observability signals trapped in separate pillars? Logs in one place, metrics in another, both losing context? At ClickHouse, we faced this challenge at a massive scale. Our solution was to abandon the traditional model and embrace a new philosophy: store everything, aggregate nothing. This talk charts our journey to 100 PB and 500 trillion rows, centered on the concept of “wide events.” Instead of shipping a simple log message and a separate, pre-aggregated metric, we store a single, context-rich event containing every possible dimension. This shift from three pillars to a single warehouse of high-cardinality telemetry was a game-changer. The key to this model is using ClickHouse itself as our observability backend. This unlocks unbounded query flexibility through full SQL. When an engineer asks “what’s the p95 pod replacement time after termination?”, we don’t say “let me ship a new metric.” We write a SQL query.
Vlad Seliverstov leads the internal observability team at ClickHouse, overseeing the monitoring of ClickHouse Cloud, which handles over 100 petabytes of data and 500 trillion events. With more than a decade of SRE experience at Datadog, Dropbox, and Facebook, Vlad now focuses on building and scaling ClickHouse’s in-house observability platform.
