Supervision Tree

Liteskill uses a rest_for_one supervision strategy. If an infrastructure child (like Repo or PubSub) crashes, all children started after it restart too, re-establishing subscriptions and connections.

Child Process Order

The supervision tree starts children in this order:

1. LiteskillWeb.Telemetry — Telemetry metrics and poller
2. Liteskill.Desktop.PostgresManager — (Desktop mode only) Starts bundled PostgreSQL
3. Liteskill.Repo — Ecto repository / database connection pool
4. DNSCluster — DNS-based node clustering
5. Phoenix.PubSub — PubSub server (Liteskill.PubSub)
6. Liteskill.Rag.EmbedQueue — Embedding request queue (skipped in test)
7. Oban — Background job processing (queues: default, rag_ingest, data_sync, agent_runs)
8. Boot tasks — (non-test) Ensures admin user, system roles, env providers, and settings; auto-provisions admin in single-user mode
9. Liteskill.OpenRouter.StateStore — OAuth PKCE state storage for OpenRouter
10. LiteskillWeb.Plugs.RateLimiter.Sweeper — Periodic ETS cleanup for rate limiter
11. Task.Supervisor (Liteskill.TaskSupervisor) — For LLM streaming and async work
12. Liteskill.Chat.StreamRegistry — Monitors active LLM stream tasks, triggers recovery on crash
13. Registry (Liteskill.LlmGateway.GateRegistry) — Per-provider gate registry
14. DynamicSupervisor (Liteskill.LlmGateway.GateSupervisor) — Dynamic circuit breaker gates
15. Liteskill.LlmGateway.TokenBucket.Sweeper — Periodic ETS cleanup for token buckets
16. Liteskill.Chat.Projector — Event → projection table updater
17. Liteskill.Chat.StreamRecovery — Periodic sweep for stuck streaming conversations
18. Liteskill.Schedules.ScheduleTick — (non-test) Periodic check for due schedules
19. LiteskillWeb.Endpoint — Phoenix HTTP endpoint (started last)

LLM Gateway

The LLM Gateway provides per-provider concurrency control and circuit breaking:

• GateRegistry — Unique registry keyed by provider ID
• GateSupervisor — Dynamically spawns Gate processes per provider
• TokenBucket — ETS-based rate limiting with periodic sweeper

Stream Registry

Liteskill.Chat.StreamRegistry monitors active LLM streaming tasks. If a streaming task crashes, the registry detects the :DOWN message and triggers stream recovery, preventing conversations from getting stuck in the :streaming state.

Stream Recovery

Liteskill.Chat.StreamRecovery is a periodic sweeper that detects conversations stuck in streaming state for more than 5 minutes and automatically recovers them by failing the stream.