Changelog¶

All notable changes to taskito are documented here.

0.2.3¶

Features¶

• Postgres storage backend — optional PostgreSQL backend for multi-machine workers and higher write throughput (pip install taskito[postgres]); full feature parity with SQLite including jobs, DLQ, rate limiting, periodic tasks, circuit breakers, workers, metrics, and logs
• Django integration — TASKITO_BACKEND, TASKITO_DB_URL, TASKITO_SCHEMA settings for configuring the backend from Django projects

Build & Tooling¶

• Pre-commit hooks — Added .pre-commit-config.yaml with local hooks for cargo fmt, cargo clippy, ruff check, ruff format, and mypy

Critical Fixes¶

• Dashboard dead routes — Moved /logs and /replay-history handlers above the generic catch-all in dashboard.py, fixing 404s on these endpoints
• Stale __version__ — Replaced hardcoded version with importlib.metadata.version() with fallback
• retry_dead non-atomic — Wrapped enqueue + delete in a single transaction (SQLite & Postgres), preventing ghost dead letters on partial failure
• retry_dead hardcoded defaults — Added priority, max_retries, timeout_ms, result_ttl_ms columns to dead_letter table; replayed jobs now preserve their original configuration
• enqueue_unique race condition — Wrapped check + insert in a transaction; catches unique constraint violations to return the existing job instead of erroring
• now_millis() panic — Replaced .expect() with .unwrap_or(Duration::ZERO) to prevent scheduler panic on clock issues
• reap_stale double error records — Removed redundant storage.fail() call; handle_result already records the failure
• README cron format — Updated example to correct 6-field format: "0 0 */6 * * *"

Important Fixes¶

• result.py hardcoded cloudpickle — job.result() now uses the queue's configured serializer for deserialization
• Context leak on deserialization failure — Wrapped deserialization + call in closure; _clear_context always runs via finally
• OTel spans not thread-safe — Added threading.Lock around all _spans dict access in OpenTelemetryMiddleware
• build_periodic_payload misleading _kwargs param — Removed unused parameter, added explanatory comment
• Tokio runtime panic — Replaced .expect() with graceful error handling on runtime creation
• dequeue LIMIT 10 — Increased to 100 for better throughput under load (both SQLite & Postgres)
• check_periodic not atomic — Uses enqueue_unique with deterministic key to prevent duplicate periodic jobs
• SQLite purge_completed_with_ttl no transaction — Wrapped in transaction for consistency
• Django admin status validation — Added try/except around queue.list_jobs() to handle connection errors gracefully
• Silent job loss on get_job None — Added warn! logging when a dequeued job ID returns None
• Cascade cleanup on job purge — purge_completed() and purge_completed_with_ttl() now automatically delete orphaned child records (job_errors, task_logs, task_metrics, job_dependencies, replay_history) when removing completed jobs

Minor Fixes¶

• cascade_cancel O(n²) — Replaced Vec::contains with HashSet for dependency lookups (both backends)
• chain.apply() hardcoded 300s timeout — Now derives timeout from sig.options.get("timeout", 300)
• _FakeJobResult missing refresh() — Added no-op method for test mode compatibility
• Storage trait doc outdated — Updated to mention both SQLite and Postgres backends
• wall_time_ns truncation — Uses .try_into().unwrap_or(i64::MAX) to prevent silent overflow

0.2.2¶

• Added readme field to pyproject.toml so PyPI displays the project description.

0.2.1¶

Re-release of 0.2.0 — PyPI does not allow re-uploads of deleted versions.

0.2.0¶

Core Reliability¶

• Exception hierarchy (F8) — TaskitoError base class with TaskTimeoutError, SoftTimeoutError, TaskCancelledError, MaxRetriesExceededError, SerializationError, CircuitBreakerOpenError, RateLimitExceededError, JobNotFoundError, QueueError
• Pluggable serializers (F2) — CloudpickleSerializer (default), JsonSerializer, or custom Serializer protocol
• Exception filtering (F1) — retry_on and dont_retry_on parameters for selective retries
• Cancel running tasks (F3) — cooperative cancellation with queue.cancel_running_job() and current_job.check_cancelled()
• Soft timeouts (F4) — soft_timeout parameter with current_job.check_timeout() for cooperative time limits

Developer Experience¶

• Per-task middleware (F5) — TaskMiddleware base class with before(), after(), on_retry() hooks; queue-level and per-task registration
• Worker heartbeat (F6) — queue.workers() / await queue.aworkers() to monitor worker health; GET /api/workers dashboard endpoint; workers table in schema
• Job expiration (F7) — expires parameter on apply_async() to skip time-sensitive jobs that weren't started in time
• Result TTL per job (F11) — result_ttl parameter on apply_async() to override global cleanup policy per job

Power Features¶

• chunks / starmap (F9) — chunks(task, items, chunk_size) and starmap(task, args_list) canvas primitives
• Group concurrency (F10) — max_concurrency parameter on group() to limit parallel execution
• OpenTelemetry (F12) — OpenTelemetryMiddleware for distributed tracing; install with pip install taskito[otel]

Build & Tooling¶

• Zensical site configuration (zensical.toml)
• Makefile for docs / docs-serve commands
• Lock file (uv.lock) for reproducible builds

Bug Fixes¶

• Fixed "Copy as Markdown" table cells rendering empty for SVG/img emoji icons

Internal¶

• Hardened core scheduler and rate limiter
• Reorganized resilience modules and storage layer

0.1.1¶

Features¶

• Web dashboard -- taskito dashboard --app myapp:queue serves a built-in monitoring UI with dark mode, auto-refresh, job detail views, and dead letter management
• FastAPI integration -- TaskitoRouter provides a pre-built APIRouter with endpoints for stats, job status, progress streaming (SSE), and dead letter management
• Testing utilities -- queue.test_mode() context manager for running tasks synchronously without a worker; includes TestResult, TestResults with filtering
• CLI dashboard command -- taskito dashboard command with --host and --port options
• Celery-style worker banner -- Worker startup now displays registered tasks, queues, and configuration
• Async result awaiting -- await job.aresult() for non-blocking result fetching

Changes¶

• Renamed python/ to py_src/ and rust/ to crates/ for clearer project structure
• Default db_path now uses .taskito/ directory, with automatic directory creation

0.1.0¶

Initial release

Features¶

• Task queue — @queue.task() decorator with .delay() and .apply_async()
• Priority queues — integer priority levels, higher values processed first
• Retry with exponential backoff — configurable max retries, backoff multiplier, and jitter
• Dead letter queue — failed jobs preserved for inspection and replay
• Rate limiting — token bucket algorithm with "N/s", "N/m", "N/h" syntax
• Task workflows — chain, group, and chord primitives
• Periodic tasks — cron-scheduled tasks with 6-field expressions (seconds granularity)
• Progress tracking — current_job.update_progress() from inside tasks
• Job cancellation — cancel pending jobs before execution
• Unique tasks — deduplicate active jobs by key
• Batch enqueue — task.map() and queue.enqueue_many() with single-transaction inserts
• Named queues — route tasks to isolated queues, subscribe workers selectively
• Hooks — before_task, after_task, on_success, on_failure
• Async support — aresult(), astats(), arun_worker(), and more
• Job context — current_job.id, .task_name, .retry_count, .queue_name
• Error history — per-attempt error tracking via job.errors
• Result TTL — automatic cleanup of completed/dead jobs
• CLI — taskito worker and taskito info --watch
• Metadata — attach arbitrary JSON to jobs

Architecture¶

• Rust core with PyO3 bindings
• SQLite storage with WAL mode and Diesel ORM
• Tokio async scheduler with 50ms poll interval
• OS thread worker pool with crossbeam channels
• cloudpickle serialization for arguments and results