Health and logs

The containers

Container	What it is	Runs on
`quasar-seed`	The one container you declare. It makes sure the recovery actor exists.	Every machine
`quasar-recovery`	The recovery actor. Creates and replaces the other Quasar services; answers `quasar-recovery status`.	Every machine
`quasar-postgres`	All state.	Control plane, with Quasar’s own database
`quasar-control-plane`	API, signaling, scheduler, web app. Runs migrations at startup.	Control plane
`quasar-node-agent`	Runs sessions: compositor, encoder, app containers. Host networking.	GPU hosts

During a session you’ll also see the app container and an audio sidecar (PipeWire). During an update, a stopped quasar-node-agent.kept may briefly appear: the old agent, kept until the new one is verified.

On a legacy Compose install, use docker compose -f deploy/docker-compose.yml logs <service> and docker compose -f deploy/docker-compose.yml exec <service> <command> for logs and container commands. On Podman, use podman in place of docker.

Health checks

Control plane (works over plain HTTP, before certificates are set up):

curl http://localhost:8080/health
# {"status":"ok","db":"ok"}

Node agent, on its host:

curl http://127.0.0.1:9091/health
# {"status":"ok","sessions":0,"connected":true}

connected: false means the agent is up but can’t reach the control plane.

Containers and the recovery actor’s view:

docker ps --filter label=io.quasar.installation
docker exec quasar-recovery quasar-recovery status

Logs

docker logs --tail 100 quasar-control-plane
docker logs --tail 100 quasar-node-agent
docker logs --tail 100 quasar-recovery

Add -f when you want to follow new messages.

Node agent errors only:

docker logs --tail 2000 quasar-node-agent 2>&1 \
  | grep -iE '\b(error|fatal|panic)\b'

Seed and recovery actor lines carry a token=, listed in Install and startup problems.

Log lines worth recognising

Good

Line	Meaning
`render_node <raw> -> <canonical>`	The agent resolved a render node symlink (expected on multi-GPU hosts).
`EGL hardware-acceleration enabled`	The compositor has hardware acceleration.
`codec resolved`	The session’s codec decision and why. Check here for an unexpected codec.

Bad

Line	Meaning
`no VA H264 encoder found`	The VA encoder didn’t register. Usually a stale GStreamer registry or a stray env var forcing software Mesa.
`quasar-renderer-degraded`	Frame import fell back to software. Two within 30 s fail the session unless `QUASAR_REQUIRE_HW_RENDER=0`.
`media path interrupted`	Catch-all. The cause is usually a few lines above, often the app exiting at once or lacking network.
`Steam needs to be`	Steam couldn’t start, almost always no network. See The Steam library.
`no migration found for version N`	Control plane rolled back below the database. See the hard rule.
`no command specified`	An overlay cleared the command on an image with no entrypoint.

Reading a session, not a log

For a specific session, the admin session detail is better than logs. See Sessions and audit log and Diagnostics.

Checking the whole stack quickly

On a machine running Quasar from a repository checkout (not a registry install):

make diagnose          # container states, health, recent errors
make diagnose-bundle   # the same, redacted, to share

See Developing Quasar.

Metric retention

Running sessions keep a rolling hour of telemetry; ended sessions keep it for 24 hours by default. Take a diagnostic bundle before then if you need it longer.