Replace lock-based request serialization with queue-based approach:
- Each worker now has a dedicated asyncio.Queue and consumer task
- route_request() submits (request, future) to queue and awaits future
- Consumer task processes requests sequentially per worker
- No lock contention - pure async queue operations
Benefits:
- Clearer separation of concerns
- Better visibility into request backlog (queue.qsize())
- Eliminates lock contention under high concurrency
Changes:
- worker_locks dict replaced with worker_queues and worker_consumers
- Added _start_worker_consumer() to create queue and consumer per worker
- Added _execute_on_worker() for actual worker communication
- Updated _cleanup_worker() to cancel consumer tasks
- Updated stop() to cancel all consumers before shutdown
Benchmark results (4 workers, isolated):
- throughput_10ms: 333 req/s, 0 failures
- overload_10ms (200 clients): 334 req/s, 0 failures
- All tests pass with perfect round-robin distribution
Introduce Dirty Arbiters - a separate process pool for executing
long-running, blocking operations (AI model loading, heavy computation)
without blocking HTTP workers. Inspired by Erlang's dirty schedulers.
Key features:
- Completely separate from HTTP workers - can be killed/restarted independently
- Stateful - loaded resources persist in dirty worker memory
- Message-passing IPC via Unix sockets with JSON serialization
- Explicit execute() API from HTTP workers
- Asyncio-based for clean concurrent handling
Architecture:
- DirtyArbiter: manages the dirty worker pool, routes requests
- DirtyWorker: executes functions, maintains state, handles requests
- DirtyClient: sync/async API for HTTP workers to call dirty apps
- DirtyProtocol: length-prefixed JSON messages over Unix sockets
- DirtyApp: base class for dirty applications
Configuration options:
- dirty_apps: list of import paths for dirty applications
- dirty_workers: number of dirty workers (default: 0)
- dirty_timeout: task timeout in seconds (default: 300)
- dirty_graceful_timeout: shutdown timeout (default: 30)
Lifecycle hooks:
- on_dirty_starting(arbiter)
- dirty_post_fork(arbiter, worker)
- dirty_worker_init(worker)
- dirty_worker_exit(arbiter, worker)
Includes comprehensive test suite with 164 tests covering:
- Protocol encoding/decoding
- Worker and arbiter lifecycle
- Client sync/async APIs
- Signal handling
- Error handling and timeouts
- Integration tests
