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langflow/docs
Gabriel Luiz Freitas Almeida 2ddac97c77 feat(job_queue): cross-worker cancel + polling watchdog for multi-worker Redis-backed builds (#13084)
* feat: implement Redis job queue and fakeredis support
- Refactored the job queue service to support Redis-backed management for cross-worker scaling.
- Added environment variables for configuration:
    - `LANGFLOW_JOB_QUEUE_TYPE=redis`
    - `LANGFLOW_REDIS_QUEUE_DB=1`
- Updated job ownership methods to be asynchronous for improved concurrency handling.
- Enhanced Redis cache service with namespacing via key prefixes.
- Introduced `fakeredis` for in-memory Redis simulation in testin>
- Added comprehensive unit tests for Redis job queue components.

* fix: run  experimental warning for RedisCache usage only once

- Introduced a mechanism to emit a one-time warning for the RedisCache experimental feature during server runtime.
- The warning is logged only if no other worker has already emitted it, ensuring clarity for users regarding the experimental status of RedisCache.
- The implementation includes a temporary file check to prevent multiple warnings across different processes.

* docs: document environment variables for worker management
- Added documentation for LANGFLOW_GUNICORN_PRELOAD to explain preloading for better performance.
- Detailed the use of LANGFLOW_JOB_QUEUE_TYPE for specifying backends (e.g., Redis).
- Included LANGFLOW_REDIS_QUEUE_DB to define the database index for job queues.
- Updated the "High-Load Environments" guide with these optimal configurations.

* docs: updated 'High-load and multi-worker environments' section

* feat: enhance RedisJobQueueService with consumer wrapper management
- Introduced a caching mechanism for Redis stream consumers to optimize job data retrieval.
- Added methods to manage consumer wrappers, ensuring they are reused across sequential polls.
- Implemented cleanup logic to cancel and clear consumer wrappers during job cleanup and service stop.
- Expanded unit tests to verify consumer wrapper reuse and cleanup behavior.

* fix: ensure Redis keys are deleted during job cleanup even on cancellation

- Updated the cleanup_job method in RedisJobQueueService to guarantee Redis keys are removed even if the job cleanup is interrupted by a CancelledError.
- Added a new unit test to verify that Redis keys are deleted correctly when cleanup is called during task cancellation.

* fix: manage connection check task in RedisJobQueueService

- Added handling for the connection check task in the stop method to ensure it is properly cancelled and awaited if still running.
- This change improves resource management and prevents potential issues during service shutdown.

* fix: handle unpublished sentinel requeue on cancellation in RedisJobQueueService

- Updated the job processing logic to ensure that if a job is cancelled during the xadd operation, the unpublished sentinel is requeued instead of being dropped.
- Introduced a new unit test to verify this behavior, ensuring robustness in job handling during cancellations.

* fix: improve Redis job queue service with enhanced configuration and cleanup

- Added atexit cleanup to remove stale temporary files for RedisCache.
- Refactored Redis job queue service to use shared constants for stream prefixes, improving maintainability.
- Updated type hints for better clarity and consistency in RedisQueueWrapper and RedisJobQueueService.
- Enhanced error handling with configurable backoff for transient read failures.

* fix: enhance Redis job queue service with maxlen configuration for xadd

- Updated the xadd method in RedisJobQueueService to include maxlen and approximate parameters, improving stream management and preventing excessive memory usage.

* fix: enhance job ownership retrieval in RedisJobQueueService

- Updated the get_job_owner method to refresh the Redis key TTL on successful lookups, ensuring long-running jobs maintain their ownership anchor.
- Improved code clarity by extracting the owner key into a variable and adding detailed docstring explanations for better understanding of the TTL management.

* fix: improve job ownership handling in cleanup_job method

- Enhanced the cleanup_job method in RedisJobQueueService to accurately capture job ownership before deleting Redis keys, preventing potential data corruption in multi-worker scenarios.
- Added comments for clarity on ownership logic and its implications during job cleanup.

* fix: optimize TTL management in RedisJobQueueService

- Introduced periodic TTL refresh logic in the _bridge_to_redis method to enhance Redis stream management, reducing round-trips and improving throughput.
- Added constants for TTL refresh events and seconds to maintain clarity and configurability.
- Updated event handling to ensure TTL is refreshed appropriately based on event count and time elapsed.

* fix: improve event handling in flow response management

- Removed unnecessary error handling for missing event tasks in get_flow_events_response, allowing for smoother operation when no task exists.
- Updated create_flow_response to handle optional event_task parameter, ensuring proper cleanup during disconnections.
- Added unit tests to verify behavior when event tasks are missing, enhancing robustness in streaming scenarios.

* fix: enhance RedisQueueWrapper with startup grace period and stream observation

- Added a startup grace period to prevent premature end-of-stream signals when the producer has not yet issued its first XADD.
- Introduced a flag to track whether the stream has been observed, improving the handling of early polling scenarios.
- Updated logic to ensure proper handling of stream existence checks and logging for better debugging during job processing.

* fix: implement cleanup for old cross-worker job queues in RedisJobQueueService

- Added a new method to clean up done cross-worker consumer wrappers that are not owned by the current worker, ensuring proper resource management.
- Enhanced the existing cleanup logic to prevent memory leaks by explicitly pruning stale entries from the consumer wrappers dictionary.
- Improved logging to provide better visibility into the cleanup process for cross-worker jobs.

* fix: enhance job handling in JobQueueService with guarded task execution

- Updated the start_job method to accept a Coroutine type for task_coro, ensuring type safety.
- Introduced a new _guarded_task method to wrap job coroutines, guaranteeing that unhandled exceptions emit an error event and write a sentinel to the Redis Stream, improving reliability in job processing.
- Enhanced documentation to clarify the behavior of the new task handling mechanism and its implications for cross-worker consumers.

* fix: improve client disconnection handling in create_flow_response

- Added logging for scenarios where a client disconnects without an associated event_task, clarifying that the producer will continue running until the build completes.
- Documented the limitation regarding cross-worker passive disconnects and the need for a Redis side-channel for proper cancellation, enhancing observability in the logs.

* fix: enhance RedisQueueWrapper to manage initial read state and buffer behavior

- Introduced a flag to track the completion of the first XREAD call, ensuring proper buffer management during the initial read phase.
- Updated the empty method to reflect the state of the buffer accurately, preventing premature exits from the drain loop until the first read is complete.
- Improved documentation to clarify the behavior of the new flag and its impact on job processing.

* fix: clarify RedisQueueWrapper behavior in tests for buffer state and no-op operations

- Updated test documentation to explain the behavior of the empty() method in relation to the first XREAD completion, ensuring accurate understanding of buffer state during job processing.
- Adjusted assertions in tests to reflect the intended behavior of the RedisQueueWrapper, specifically regarding the no-op nature of put_nowait and its impact on the internal buffer.

* fix: update dependencies in pyproject.toml and uv.lock

- Added fakeredis dependency with a minimum version of 2.0.0 to both pyproject.toml and uv.lock files.
- Ensured proper formatting and comments in pyproject.toml for clarity on onnxruntime version constraints.

* feat(job_queue): cross-worker cancel via Redis pub/sub + configurable startup grace

- Add LANGFLOW_REDIS_QUEUE_STARTUP_GRACE_S (default 30.0) so deployments
  with slow producer-worker cold-start can bump the wrapper's early-poll
  grace period without editing code.

- Add LANGFLOW_REDIS_QUEUE_CANCEL_CHANNEL_ENABLED (default True) wiring a
  per-job Redis pub/sub channel (langflow:cancel:<job_id>) so
  POST /build/{job_id}/cancel works cross-worker. The producer subscribes
  when the job starts; any worker can publish via
  RedisJobQueueService.signal_cancel and the subscriber cancels the local
  build task on receipt.

- cancel_flow_build now falls back to signal_cancel when event_task is
  None on this worker, replacing the previous no-op for cross-worker
  cancellation.

- Subscriber tasks are tracked in _cancel_subscribers and torn down in
  cleanup_job/stop alongside the bridge tasks.

- Tests: 3 new unit tests covering cross-worker signal propagation, the
  disabled-flag no-op, and the wrapper's per-instance startup_grace_s
  override.

* fix(job_queue): close three cross-worker cancel corner cases

Discovered by a deeper local stress pass over the prototype:

1. **Signal-before-subscribe race**: publish from worker A would be lost if
   worker B's subscriber had not finished SUBSCRIBE yet. signal_cancel now
   also sets a short-lived langflow:cancel-marker:<job_id> key, and the
   subscriber checks it immediately after subscribing — so a cancel that
   raced the SUBSCRIBE still fires.

2. **Restart subscriber leak**: start_job called twice for the same job_id
   silently overwrote the dict entry and orphaned the previous subscriber
   (and its Redis pubsub connection). Now cancels the previous subscriber
   before storing the new one.

3. **Slow end-of-stream after cross-worker cancel**: cancelling the local
   task did not unblock cross-worker consumers — the bridge sat waiting on
   local_queue.get() until periodic cleanup ran ~5 min later. The
   subscriber now puts a sentinel on the local queue after task.cancel()
   so the bridge flushes a clean end-of-stream marker to Redis. Measured
   8ms from signal_cancel to consumer end-of-stream against real Redis.

Tests: 3 new unit tests covering each corner case; 9-scenario local
stress harness against real Redis confirms all green.

* refactor(job_queue): address self-review of cross-worker cancel

Addresses the eight points from the PR review of the previous commits:

1. Configurable marker TTL — new LANGFLOW_REDIS_QUEUE_CANCEL_MARKER_TTL
   setting (default 60s) replaces the hardcoded constant.

2. Connection-pool footprint is O(1) in active jobs — replaced the per-job
   pub/sub subscriber with a single PSUBSCRIBE dispatcher per worker
   listening on langflow:cancel:*.

3. Prompt stream cleanup after cancel — the dispatcher now waits for the
   bridge to drain the sentinel before triggering cleanup_job, so the
   Redis stream + owner keys are deleted within milliseconds instead of
   waiting for the 5-minute periodic cleanup grace.

4. signal_cancel raises on Redis failure — publish errors propagate to the
   caller instead of silently returning 0. The cancel HTTP endpoint
   catches and returns False so the client can retry.

5. Auth note in signal_cancel docstring — explicit note that callers must
   verify authorization; the HTTP cancel endpoint already does via
   _verify_job_ownership before calling through.

6. Structured cancel logging — INFO-level logs on publish, marker hit,
   owned dispatch, foreign dispatch. _cancel_stats counters expose
   {published, marker_hit, dispatched_owned, dispatched_foreign,
   publish_errors} for ops/metrics.

7. redis-py version compatibility — _close_pubsub falls back from
   aclose() to close(), handles both sync and async return values.

8. Fire-and-forget tasks hold strong references — _background_tasks set
   keeps marker checks and post-cancel cleanups from being GC'd before
   they run; each task self-removes via add_done_callback. stop() drains
   the set on shutdown.

Tests: 24 passing (1 skipped due to timing); deep stress harness verified
6 scenarios against real Redis.

* feat(job_queue): propagate client disconnect via signal_cancel for cross-worker builds

Closes the remaining cross-worker passive-disconnect gap. Previously, when a
client closed its streaming connection on a non-owner worker, the producer
worker kept emitting events until the build completed naturally. Now the
disconnect handler in create_flow_response publishes a cross-worker cancel
via signal_cancel so the owning worker stops promptly.

- create_flow_response accepts optional queue_service + job_id kwargs and
  uses them in on_disconnect for the cross-worker case (event_task is None).
  Both are keyword-only and default to None, preserving the single-worker
  contract.
- get_flow_events_response wires both through.
- New unit test test_cross_worker_disconnect_publishes_signal_cancel covers
  the full pubsub propagation path with two services sharing a fake Redis.
- Tested end-to-end against real Redis with a two-worker harness: 10/10
  scenarios pass, including the new disconnect propagation case.

* feat(job_queue): production-harden cross-worker cancel for multi-worker setups

Five complementary improvements that make the Redis-backed cancel/lifecycle
path safe to leave running unattended under real ops pressure.

A. Dispatcher reconnect loop with exponential backoff. _run_cancel_dispatcher
   used to exit silently on any Redis-side error (broker restart, network
   blip, listen() hiccup), leaving the worker permanently blind to
   cross-worker cancels until process restart. The loop now reconnects with
   capped backoff (max 30s), and a dispatcher_reconnects counter exposes the
   event for monitoring.

B. Outer timeout on _post_cancel_cleanup. The background cleanup task could
   hang indefinitely if cleanup_job stalled (Redis pathology during DELETE);
   wrap in asyncio.wait_for and let periodic cleanup retry instead.

C. Public metrics_snapshot() on JobQueueService (memory + Redis backends)
   plus GET /monitor/job_queue endpoint behind get_current_active_user.
   Surfaces backend, active_jobs, bridge_count, consumer_wrapper_count,
   background_task_count, cancel_dispatcher_running, and the full
   cancel_stats counter set.

D. Deterministic rewrite of test_redis_service_signal_cancel_flushes_sentinel_to_consumer.
   The previous version was skipped roughly half the time due to a fakeredis
   timing race; the new version no-ops cleanup_job for the duration of the
   assertion so the bridge XADD ordering can be observed reliably. No more
   skipped tests in the suite (33 pass, 0 skip).

E. Polling-mode stale-client watchdog. Polling has no persistent connection
   for on_disconnect, so abandoned polling builds previously ran to natural
   completion even after the client gave up. New flow:
     * touch_activity(job_id) writes langflow:activity:<job_id> on every poll
       and on streaming-response open; consume_and_yield refreshes it every
       10s while the connection is held.
     * _run_polling_watchdog scans owned jobs every
       LANGFLOW_REDIS_QUEUE_POLLING_WATCHDOG_INTERVAL_S (default 15s) and
       publishes signal_cancel for jobs whose activity is older than
       LANGFLOW_REDIS_QUEUE_POLLING_STALE_THRESHOLD_S (default 90s).
     * Streaming clients are protected by the heartbeat refresh; threshold <=
       0 disables the watchdog entirely.
     * cleanup_job folds the activity key into the existing DEL round-trip
       so successful builds clean up after themselves.

End-to-end coverage: 33 unit tests pass (up from 25, with the previous skip
now passing deterministically); a two-worker real-Redis harness exercises 12
scenarios including dispatcher reconnect, post-cancel timeout, watchdog
reclamation, and metrics_snapshot schema completeness.

* fix(job_queue): address PR review + Codex adversarial review findings

Acts on every must-fix finding from a multi-agent review pass (code-reviewer,
pr-test-analyzer, silent-failure-hunter, comment-analyzer) plus the Codex
adversarial review. No behavior is left to chance under realistic operational
conditions.

Critical fixes:

- Streaming heartbeat now runs as an INDEPENDENT task for the lifetime of the
  response, not coupled to event yield cadence. A quiet build (long graph
  step, slow LLM, no tokens for a while) previously had no heartbeat path, so
  the polling watchdog could reclaim a live streaming client after the
  threshold. The new heartbeat fires every streaming_activity_refresh_s
  regardless of queue activity, and is cancelled cleanly on both
  on_disconnect AND natural stream end.

- Watchdog start-grace window. A new in-memory _job_start_times[job_id]
  timestamp is set in start_job() BEFORE super().start_job() so a job can
  never appear in self._queues without a corresponding start time. When the
  watchdog scans and the Redis activity key is missing, it skips the kill
  until (now - start_ts) >= threshold. Without this, a slow background
  touch_activity (event-loop pressure, Redis blip) could nuke a brand-new
  build on the very first watchdog tick — the prior code's comment promised
  the guard but didn't implement it.

- touch_activity errors are now observable. Replaces a blanket
  contextlib.suppress(Exception) with an explicit try/except that bumps
  activity_touch_errors and emits a debug log. CancelledError is no longer
  swallowed. Operators get a signal when the heartbeat is silently failing.

- Watchdog UnboundLocalError closed. Initializes last = 0.0 before the
  raw-is-None branch so a malformed activity value (parse failure) can't
  crash the entire watchdog task. Adds activity_parse_errors and
  activity_get_errors counters.

- Dispatcher except is split: ConnectionError/TimeoutError/OSError stay at
  awarning (transient Redis), every other Exception goes to aerror with
  exc_info=True AND increments dispatcher_internal_errors. Code bugs in
  _handle_cancel no longer look identical to Redis disconnects.

- _post_cancel_cleanup narrows the bridge-wait suppress to TimeoutError
  only, with a dedicated awarning naming the consequence ("cross-worker
  consumers may see late end-of-stream"). Real bridge failures bubble up
  via a separate Exception arm with awarning instead of being silent.

- Polling watchdog uses local _handle_cancel for owned jobs instead of
  round-tripping through pubsub. Faster (no Redis RTT), dispatcher-
  independent (works during a reconnect backoff), and keeps the
  cancel_stats["published"] counter honest as a count of *external* cancels.

- /monitor/job_queue gated to get_current_active_superuser instead of
  get_current_active_user — the snapshot exposes process-wide tenant
  workload + cancel activity, which matters in multi-tenant deployments.

Docstring corrections:

- Removed the "cross-worker cancel is a known limitation" remnant from
  RedisJobQueueService.get_queue_data — the limitation was closed in the
  prior commit, and the new docstring tells callers exactly how cross-worker
  cancel travels (signal_cancel → dispatcher).

- touch_activity docstring rewritten. The previous text described a
  "TTL-based reasoning" fallback that didn't exist; the new text correctly
  explains the 4x-threshold TTL and how it interacts with the watchdog's
  start-time grace window.

New tests (5 added, total 38 pass):

- test_polling_watchdog_grants_start_grace_window: brand-new job with
  deleted activity key survives until the threshold passes, then dies.
- test_polling_watchdog_skips_malformed_activity_value: malformed value
  bumps activity_parse_errors and does NOT kill the job.
- test_streaming_heartbeat_runs_independent_of_event_yield: quiet streaming
  build is not reclaimed; heartbeat task is cancelled on disconnect.
- test_concurrent_cancels_from_multiple_workers_are_idempotent: two workers
  publish cancel simultaneously, no crashes, single observable cancel.
- test_dispatcher_internal_error_logged_at_error_level: bug in
  _handle_cancel bumps dispatcher_internal_errors and dispatcher_reconnects;
  the dispatcher task is still running afterwards.

Plus: test_metrics_snapshot_exposes_cancel_stats_and_counters now pins the
full cancel_stats key set (using set equality), so adding an increment
without registering the key — or vice versa — fails the test instead of
producing a silent KeyError in production.

End-to-end coverage: 38 unit tests pass; the two-worker real-Redis harness
passes all 12 scenarios on commit HEAD.

* fix: harden redis job queue cancellation

* feat(job_queue): seamless redis setup + actionable errors for unsupported delivery

- RedisQueueWrapper: restore _BUFFER_MAXSIZE bounded buffer and the
  _on_fill_done done-callback safety net that release-1.10.0 added in #12588,
  so a slow consumer cannot grow the buffer without bound and a crashing or
  cancelled _fill_task cannot leave consumers stuck on await get().
- build.get_flow_events_response: explicit exhaustiveness guard. Unknown
  EventDeliveryType values now return HTTP 400 with the supported set and a
  remediation hint instead of silently falling through to the polling path.
- lfx settings.set_event_delivery: when workers > 1 without a redis queue,
  upgrade the warning to name the requested mode, the forced fallback, and
  the LANGFLOW_JOB_QUEUE_TYPE env var that would preserve the original mode.
- Tests: port the three RedisQueueWrapper safety tests from release-1.10.0
  and add coverage for the new event_delivery guard.

* fix(job_queue): polling watchdog only watches jobs with a registered owner

Surfaced by locust load testing on a Redis-queue, 2-worker setup:

  2016 requests / 2016 polling_watchdog_kills (1:1 ratio)

TaskService.launch_task uses JobQueueService.start_job for server-internal
tasks (telemetry, background work) without calling register_job_owner.
These tasks never refresh the activity heartbeat because no polling
client is involved, so the watchdog's start-time fallback was killing
every single one once it crossed polling_stale_threshold_s.

Under fast-completing flows the user-visible result was unaffected (the
build finished before the watchdog struck) — but a long-running internal
task (slow LLM call, retrieval, etc.) would be cancelled mid-flight even
though no one was waiting on it.

Scope the watchdog to jobs in self._job_owners: user-facing flow builds
register an owner; TaskService tasks don't.  After this change the same
locust run reports polling_watchdog_kills=0 and dispatched_owned=0.

Existing watchdog tests register an owner explicitly to mirror the real
flow path.  Adds a regression test (TaskService-style start_job with no
owner must not be reclaimed).

* test(job_queue): add coverage for fixes surfaced by load testing

Three regression tests for the recent fixes:

- TaskService integration: launch a task through
  TaskService.fire_and_forget_task and assert the polling watchdog
  leaves it alone (no owner registered, no kill).  Catches a future
  regression where someone adds register_job_owner inside TaskService.

- Settings multi-worker warning: verify Settings.set_event_delivery
  warns with the requested mode AND names LANGFLOW_JOB_QUEUE_TYPE in
  the fallback log when workers > 1 and the job queue is in-memory.
  An operator seeing missing events needs that env var name to fix it.

- Bounded buffer backpressure: floods the fill task past the maxsize
  ceiling and verifies qsize() never exceeds _BUFFER_MAXSIZE.  The
  previous test only asserted the constant, not the behavior.

Skipped two suggested tests:
- TestClient version of the unknown-event_delivery guard: FastAPI's
  enum validation returns 422 before our handler runs, so HTTP cannot
  reach the defensive 400.  The existing unit test is the right test.
- Exact watchdog kill-count assertion (== 1): the watchdog can tick
  again before cleanup_job removes the job from _queues, making any
  exact-count check flaky on slow CI.  The existing >= 1 is correct.

* fix(job_queue): use asyncio.create_task for trace cleanup on cancel

background_tasks.add_task() is silently dropped after FastAPI drains
the POST /build response queue — by the time any cancel fires (local,
cross-worker pub/sub, or polling watchdog), the task list from the
original HTTP request is already consumed.

Replace the background_tasks call in _run_vertex_build's CancelledError
handler with asyncio.create_task(graph.end_all_traces_in_context()())
so the trace cleanup runs as an independent task regardless of the
background_tasks lifecycle.

Adds a regression test that exercises generate_flow_events end-to-end:
a blocking vertex is cancelled mid-flight and the test asserts that
end_all_traces is eventually called via the spawned task.

* [autofix.ci] apply automated fixes

* fix: addresses a few pr review findings (#13179)

* fix(job_queue): address PR review findings from cross-worker cancel implementation

- Restore _last_id cursor update to after await buffer.put() in _fill_from_redis;
  advancing before the await loses the event if the task is cancelled while put()
  is blocked on a full buffer
- Restore XREAD persistent-error grace period: track elapsed error time and deliver
  an end-of-stream sentinel after _STARTUP_GRACE_S of continuous failures instead
  of looping forever, which left consumers stuck on await get()
- Fix cancel_flow_build returning True when no task and no signal_cancel (in-memory
  backend); return False to correctly signal that cancellation did not take effect
- Decouple polling watchdog from cancel_channel_enabled; the watchdog uses only
  local state and _handle_cancel with no pub/sub dependency, so disabling the
  cancel channel must not silently disable stale-client reclamation
- Restore _BUFFER_MAXSIZE to 1000 (reverts unexplained 10x increase to 10_000)

* test(job_queue): add regression coverage for PR review fixes

- test_fill_from_redis_last_id_not_advanced_before_put_completes: verifies
  the XREAD cursor (_last_id) stays at the prior message's position when the
  fill task is cancelled while put() is blocked on a full buffer
- test_fill_from_redis_persistent_xread_error_delivers_sentinel: verifies a
  persistent XREAD failure eventually delivers the end-of-stream sentinel
  after _STARTUP_GRACE_S of continuous errors (not an infinite retry loop)
- test_cancel_flow_build_returns_false_for_in_memory_backend_without_task:
  verifies cancel_flow_build returns False when no local task exists and the
  queue service has no cross-worker cancel path
- test_polling_watchdog_runs_when_cancel_channel_disabled: verifies the
  polling watchdog reclaims stale jobs even when cancel_channel_enabled=False

* format and comment updates

* comments

* [autofix.ci] apply automated fixes

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

* fix(job_queue): address CodeRabbit review findings

- cancel_flow_build: gate signal_cancel on a new cross_worker_cancel_enabled
  property so Redis with cancel_channel_enabled=False is treated the same as
  the in-memory backend (signal_cancel short-circuits to 0 without setting
  the marker, so the previous unconditional return True was misleading).
- _run_vertex_build: hold a strong reference to the trace cleanup task on
  CancelledError (Ruff RUF006). Tasks self-discard via add_done_callback.
- RedisQueueWrapper.finish_with_sentinel: stop awaiting on a bounded buffer
  during teardown. Evict + put_nowait mirrors _on_fill_done so shutdown can
  no longer hang on a slow or abandoned consumer.
- RedisJobQueueService.cleanup_job: wrap the Redis DEL in try/except so
  Redis failures during teardown surface as warnings instead of escaping
  stop() and explicit cancel paths.
- Settings (lfx): add Field bounds on the new Redis timing knobs so a
  negative startup_grace_s or non-positive cancel_marker_ttl /
  watchdog_interval_s fails fast at config load instead of silently
  reopening races.
- Streaming heartbeat interval: lift to module-level STREAMING_ACTIVITY_REFRESH_S
  so the heartbeat test can monkeypatch it.

Tests:
- _make_service tracks shared_client ownership so the first _stop_service
  doesn't aclose the FakeRedis under a sibling worker in cross-worker tests.
- test_polling_watchdog_skips_fresh_activity now registers a job owner;
  without it the watchdog skips the job entirely and the test would pass
  even with a broken touch_activity.
- test_streaming_heartbeat_runs_independent_of_event_yield patches the
  interval down and waits for the spawned task to refresh the activity
  timestamp, instead of calling touch_activity manually.
- Fix Ruff ARG001, EM101, TRY003, PT018 in test stubs.

* test(job_queue): cover behavior changes from CodeRabbit review fixes

- test_cancel_flow_build_returns_false_for_redis_with_disabled_cancel_channel:
  Redis with cancel_channel_enabled=False has signal_cancel but no marker
  delivery; cancel_flow_build must report failure, not false success.
- test_finish_with_sentinel_does_not_hang_on_full_buffer: regression cover for
  the await-on-bounded-buffer hang. Fills the buffer to capacity and asserts
  finish_with_sentinel returns within a tight budget.
- test_redis_service_cleanup_swallows_redis_delete_error: proxies a FakeRedis
  whose delete() raises; cleanup_job must absorb it and complete local
  teardown.
- test_redis_queue_bounds (lfx): pydantic ValidationError on negative
  startup_grace_s / non-positive cancel_marker_ttl /
  polling_watchdog_interval_s; zero remains valid for startup_grace_s and
  polling_stale_threshold_s (documented disable switch).

* log updates

* [autofix.ci] apply automated fixes

* test(cors): accept both '*' and ['*'] for Python 3.14 compatibility

pydantic-settings parses LANGFLOW_CORS_ORIGINS='*' as the raw string '*'
on Python 3.13 but as ['*'] (a single-element list) on Python 3.14+. The
`str | list[str]` union on Settings.cors_origins resolves differently
between versions, but both shapes carry the same 'all origins' semantic.

Updates two assertions in test_security_cors.py that previously required
the exact string form and were failing on Group 4 / Python 3.14 in CI:
- test_default_cors_settings_current_behavior
- test_wildcard_with_credentials_allowed_current_behavior

The PR itself (cross-worker cancel + polling watchdog) is unrelated to
CORS handling -- the failure is a Python-3.14-introduced incompatibility
in this pre-existing test that happens to surface against this branch's
CI matrix.

* [autofix.ci] apply automated fixes

---------

Co-authored-by: Arek Mateusiak <arek@a4bits.com>
Co-authored-by: Jordan Frazier <122494242+jordanrfrazier@users.noreply.github.com>
Co-authored-by: Jordan Frazier <jordan.frazier@datastax.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
2026-05-25 19:15:05 +00:00
..
2025-02-06 17:44:46 +00:00
2026-03-18 20:03:49 +00:00
2026-04-14 02:07:01 +00:00

Website

This website is built using Docusaurus 3, a modern static website generator.

Installation

$ npm install

Local Development

$ npm run start

This command starts a local development server and opens up a browser window. Most changes are reflected live without having to restart the server.

Build

$ npm run build

This command generates static content into the build directory and can be served using any static contents hosting service, including npm run serve.

Import code snippets from the repo with a line range

To pull a slice of a file into the docs, source the content with raw-loader and present the code with the CodeSnippet component. For a working example, see the Components overview.

import CodeSnippet from "@site/src/components/CodeSnippet";
import customComponent from "!!raw-loader!@langflow/src/lfx/src/lfx/custom/custom_component/custom_component.py";

<CodeSnippet
  source={customComponent}
  startLine={41}
  endLine={74}
  language="python"
  title="CustomComponent metadata (from codebase)"
  showLineNumbers
/>

Docusaurus Versioning

The versioning configuration is found in docusaurus.config.js.

Versioning example for release version 1.9.x on top of 1.8.x:

  1. Before release, the docs in the active release branch should already be set to 1.8.x, the current version.
  2. When ready to release 1.9.x, create a branch and run npm run docs:version -- 1.9.0 to snapshot the current docs.
  3. After creating a new version, update docusaurus.config.js to include the 1.9.0 release:
docs: {
  lastVersion: '1.9.0',
  versions: {
    '1.9.0': {
      label: '1.9.x',
      path: '1.9.0',
    },
    '1.8.0': {
      label: '1.8.x',
      path: '1.8.0',
    },
  },
},
  1. Test the deployment locally:
npm run build
npm run serve
  1. Create a pull request to main, and merge to create your new release.
  2. To create version 2.0.x, repeat the process: update the active release branch docs to 2.0.x when you begin working on it, then when ready to release, run npm run docs:version -- 2.0.0, update docusaurus.config.js with labels using .x notation, and merge to main.
  • lastVersion = the most recent released version (shown as "latest" in the UI).

See the Docusaurus docs for more info.

Disable versioning

  1. Remove the versions configuration from docusaurus.config.js.
  2. Delete the docs/versioned_docs/ and docs/versioned_sidebars/ directories.
  3. Delete docs/versions.json.

References

Deployment

Using SSH:

$ USE_SSH=true npm run deploy

Not using SSH:

$ GIT_USER=<Your GitHub username> npm run deploy

If you are using GitHub pages for hosting, this command is a convenient way to build the website and push to the gh-pages branch.