Module metrics 

Structs

RoomHostedGuard

Enums

PoolKind

Functions

init_from_env

record_engine_gc

Isolate-wide GC and heap, polled from the engine rather than parsed from a log the graal fleet does not write. Cumulative, so rate(engine_gc_pause_millis_total) / 1000 is the fraction of wall clock stopped, which is the figure that identified #684. Every room on the node shares one isolate, so a collection here stops all of them at once. The collection counters carry a collector label and are emitted by record_engine_gc_collector; emitting an unlabelled copy of the same name here would double every sum.

record_engine_gc_collector

Split by collector. Incremental collections are a few milliseconds and harmless; a complete collection traces the whole live set, and this live set is a permanently reachable card database, so it costs about 1.3ms per MB whether it reclaims anything or not. Only the complete series is worth alerting on.

record_engine_session_finished

record_engine_session_started

record_engine_stall

Wall clock the engine was stopped, from a probe inside the isolate rather than from the collector. record_engine_gc_collector is the better signal where it exists, but Substrate registers collector beans for its Serial GC only, so on the G1 image it reports nothing at all and this is the only series that shows a stall. Cumulative, so rate(engine_stall_millis_total) / 1000 is the fraction of wall clock lost.

record_forge_checkpoint

record_forge_checkpoint_decision

record_forge_decision

The rules work between a seat answering and the next prompt appearing, split by seat count. Measured over two days of captures, four seats run this at a p99 of about 2.9s against 0.35s for two, and put 2-5% of decisions over two seconds where two seats put none. A fleet-wide quantile averages the many clean rooms against the few bad ones and shows neither.

record_forge_decision_stage

record_jvm_gc

Pause and retained heap reported by the engine JVM’s own GC log. The fleet ships no logs, so without this a stalled JVM is invisible from off-box.

record_relay_reconnect

record_relay_send