Jaeger v2.18.0 introduces ClickHouse as a storage backend for distributed traces. A Jaeger maintainer explains the architectural decisions behind the implementation, including schema design choices for the primary key (sorted by service_name, name, start_time rather than trace_id), typed attribute storage using ClickHouse Nested columns, and materialized views for fast service/operation lookups. Benchmarks on 10 million spans across a single-node deployment show 8.6× compression (reducing ~6 GiB to ~722 MiB), ingestion throughput above 50k spans/sec, trace retrieval averaging ~100ms, and most search queries completing under 50ms. The feature is available in alpha and leverages ClickHouse's columnar OLAP architecture to handle high-throughput append-only writes and fast analytical aggregations without a separate metrics pipeline.
