Metrics from Machine Provider (Auto-scaling):
- ci_machines_provider{state=acquired|creating|idel|used|removing} - current number of machines in given state,
- ci_machines{type=created|used|removed} - total number of machines,

Metrics from Builds with breakdown on stage and runtime state:
- ci_runner_builds{state=pending|running|finished|canceled|terminated|timedout, stage=prepare_script|build_script|after_script|archive_cache|upload_artifacts} - current number of builds in given state