Performance

Fanout does not publish a throughput headline. That is a decision, not an omission, and it is worth stating plainly because the absence otherwise reads as something to be embarrassed about.

The number that used to be here

An earlier two-vCPU report quoted specific ingest and query figures. It was withdrawn before the first public release, for reasons that had nothing to do with the numbers being unflattering:

• Its raw JSON reports and the exact benchmark-driver commit were not retained.
• Its ingest run predated mandatory ingest authentication, so it measured a path the current release does not have.

The prose was detailed. Detail is not provenance — a result nobody can reproduce from the artifacts that produced it is an anecdote with decimal places.

What a published result would have to carry

Before any figure goes back on this page, it has to ship with:

• the Fanout image digest and the benchmark-driver commit;
• complete machine, network, container and Fanout configuration;
• the raw ingest.json and mixed.json reports from that same run;
• an authenticated OTLP path matching the current release;
• repeated runs, or an explicit note that it is a single run;
• separate ingest-only and mixed read/write results.

Measure your own instead

cmd/bench is the supported load generator. It sends traces, metrics and logs, ramps to find the ingest boundary, and confirms the result at the rate it found. It can add authenticated dashboard reads on top, which is the part that matters: ingest and query contend for the same write gate, so an ingest-only number overstates what an instance does while anyone is looking at it.

Build it, create an ingest token through first-admin setup, then:

./bin/bench \
  -endpoint localhost:4317 \
  -token "$INGEST_TOKEN" \
  -report ingest.json

./bin/bench -help covers fixed-rate, query-load and metrics options.

A result describes the machine it ran on

Benchmark output describes the hardware and dataset you tested, not an equivalent vCPU count at another provider. Two machines advertised with the same core count differ in memory bandwidth, disk latency and noisy neighbours, and Fanout is sensitive to all three — storage explains why.

What to watch instead of a headline

For capacity, the useful signals are the ones an instance emits about itself: telemetry drops, sustained query latency, readiness failures, and free disk. Troubleshooting lists where they are.