Self-hosted Langfuse: tracing 7% of my AI agents, and ClickHouse logging itself

说明与用途

作者自托管 Langfuse 监控 AI 代理，但仅 7% 的调用被追踪，ClickHouse 占用了 6GB 磁盘，主要是系统日志。启用所有配置文件的追踪并禁用不必要的 ClickHouse 表后，覆盖率提升至 100%，磁盘使用量减少了一半。

问题

Only 7% of AI agent calls were traced and ClickHouse consumed 6 GiB of disk for 2.2 MiB of trace data, obscuring real usage and inflating storage costs.

结果

Tracing coverage increased from 7% to 100% across profiles, enabling accurate cost and latency analysis. Disk usage dropped by ~50% by disabling ClickHouse system logs, while trace data remained intact.

工作流

• 1. Copy Langfuse API keys into each profile’s env file. 2. Enable the Langfuse tracing plugin for each profile. 3. Set the Langfuse environment to the profile name. 4. Restart the gateway and send a probe trace from each profile to verify tagging. 5. Create a ClickHouse config.d file that removes unnecessary system log tables and sets logger level to warning. 6. Mount the config file read‑only into the container and recreate the container. 7. Verify container health, unchanged trace_log row count, and intact trace data. 8. Run a weekly script that aggregates session records and Langfuse traces to generate reports.

证据

Langfuse held 618 events across 79 traces in four weeks. That's about three traces a day.

来源

ClickHouse was using 6.03 GiB of disk. The actual Langfuse trace data in it was 2.2 MiB.

来源

The third step is the one that matters for later. Traces carry no profile tag of their own, so without it every trace lands in one undifferentiated pile.

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ClickHouse lets you override server config with a file dropped into /etc/clickhouse-server/config.d/. This one removes twelve system log tables...

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