ClickHouse Setup

Status: Upcoming — ClickHouse integration is planned but not yet implemented. The stitchd-events crate scaffolding exists; the client and schema are in progress.

Stitchd will use ClickHouse 24+ for high-volume event storage:

• Experiment evaluation events (per-context metric values)
• Experiment results and metric aggregations
• Flag evaluation telemetry (optional)

Why ClickHouse

PostgreSQL is optimized for transactional config reads/writes. Experiment events are append-only, high-throughput, and require analytical queries (aggregations, time-series). ClickHouse handles this workload efficiently without impacting the main config store.

Planned Setup

# Create the events database
clickhouse-client --query "CREATE DATABASE stitchd_events"

A future CLICKHOUSE_URL environment variable will point the server at the HTTP interface (default port 8123):

http://clickhouse.internal:8123

Docker Example (for future use)

services:
  clickhouse:
    image: clickhouse/clickhouse-server:24
    ports:
      - "8123:8123"   # HTTP interface
      - "9000:9000"   # Native protocol
    volumes:
      - ch_data:/var/lib/clickhouse

volumes:
  ch_data:

Check back when the stitchd-events crate reaches its first release milestone.