Firedancer maintains many internal performance counters for use by developers and monitoring tools, and exposes them via. a Prometheus HTTP endpoint:
::: code-group
[tiles.metric]
prometheus_listen_port = 7999:::
$ curl http://localhost:7999/metrics
# HELP tile_pid The process ID of the tile.
# TYPE tile_pid gauge
tile_pid{kind="net",kind_id="0"} 1527373
tile_pid{kind="quic",kind_id="0"} 1527370
tile_pid{kind="quic",kind_id="1"} 1527371
tile_pid{kind="verify",kind_id="0"} 1527369
tile_pid{kind="verify",kind_id="1"} 1527374
tile_pid{kind="dedup",kind_id="0"} 1527365
...::: warning WARNING
Metrics are currently only provided for developer and diagnostic use, and the endpoint or data provided may break or change in incompatible ways at any time.
:::
There are three metric types reported by Firedancer, following the Prometheus data model:
counter— A cumulative metric repesenting a monotonically increasing counter.gauge— A single numerical value that can go arbitrarily up or down.histogram— Samples observations like packet sizes and counts them in buckets.