refactor: implement generic queue worker with task-type dispatch and improved retry logic

backend/app/db/session.py

@@ -6,8 +6,6 @@ import asyncio
 from pathlib import Path
 from typing import TYPE_CHECKING
 
-from alembic import command
-from alembic.config import Config
 from sqlalchemy.exc import SQLAlchemyError
 from sqlalchemy.ext.asyncio import AsyncEngine, async_sessionmaker, create_async_engine
 from sqlmodel import SQLModel
@@ -45,8 +43,10 @@ async_session_maker = async_sessionmaker(
 logger = get_logger(__name__)
 
 
-def _alembic_config() -> Config:
+def _alembic_config():
     alembic_ini = Path(__file__).resolve().parents[2] / "alembic.ini"
+    from alembic.config import Config
+
     alembic_cfg = Config(str(alembic_ini))
     alembic_cfg.attributes["configure_logger"] = False
     return alembic_cfg
@@ -54,6 +54,8 @@ def _alembic_config() -> Config:
 
 def run_migrations() -> None:
     """Apply Alembic migrations to the latest revision."""
+    from alembic import command
+
     logger.info("Running database migrations.")
     command.upgrade(_alembic_config(), "head")
     logger.info("Database migrations complete.")

backend/app/services/queue_worker.py

@@ -0,0 +1,137 @@
+"""Generic queue worker with task-type dispatch."""
+
+from __future__ import annotations
+
+import asyncio
+import random
+from collections.abc import Awaitable, Callable
+from dataclasses import dataclass
+
+from app.core.config import settings
+from app.core.logging import get_logger
+from app.services.queue import QueuedTask, dequeue_task
+from app.services.webhooks.dispatch import (
+    process_webhook_queue_task,
+    requeue_webhook_queue_task,
+)
+from app.services.webhooks.queue import TASK_TYPE as WEBHOOK_TASK_TYPE
+
+logger = get_logger(__name__)
+
+
+@dataclass(frozen=True)
+class _TaskHandler:
+    handler: Callable[[QueuedTask], Awaitable[None]]
+    attempts_to_delay: Callable[[int], float]
+    requeue: Callable[[QueuedTask, float], bool]
+
+
+_TASK_HANDLERS: dict[str, _TaskHandler] = {
+    WEBHOOK_TASK_TYPE: _TaskHandler(
+        handler=process_webhook_queue_task,
+        attempts_to_delay=lambda attempts: min(
+            settings.rq_dispatch_retry_base_seconds * (2**max(0, attempts)),
+            settings.rq_dispatch_retry_max_seconds,
+        ),
+        requeue=requeue_webhook_queue_task,
+    ),
+}
+
+
+def _compute_jitter(base_delay: float) -> float:
+    return random.uniform(0, min(settings.rq_dispatch_retry_max_seconds / 10, base_delay * 0.1))
+
+
+async def flush_queue(*, block: bool = False, block_timeout: float = 0) -> int:
+    """Consume one queue batch and dispatch by task type."""
+    processed = 0
+    while True:
+        try:
+            task = dequeue_task(
+                settings.rq_queue_name,
+                redis_url=settings.rq_redis_url,
+                block=block,
+                block_timeout=block_timeout,
+            )
+        except Exception:
+            logger.exception(
+                "queue.worker.dequeue_failed",
+                extra={"queue_name": settings.rq_queue_name},
+            )
+            continue
+
+        if task is None:
+            break
+
+        handler = _TASK_HANDLERS.get(task.task_type)
+        if handler is None:
+            logger.warning(
+                "queue.worker.task_unhandled",
+                extra={
+                    "task_type": task.task_type,
+                    "queue_name": settings.rq_queue_name,
+                },
+            )
+            continue
+
+        try:
+            await handler.handler(task)
+            processed += 1
+            logger.info(
+                "queue.worker.success",
+                extra={
+                    "task_type": task.task_type,
+                    "attempt": task.attempts,
+                },
+            )
+        except Exception as exc:
+            logger.exception(
+                "queue.worker.failed",
+                extra={
+                    "task_type": task.task_type,
+                    "attempt": task.attempts,
+                    "error": str(exc),
+                },
+            )
+            base_delay = handler.attempts_to_delay(task.attempts)
+            delay = base_delay + _compute_jitter(base_delay)
+            if not handler.requeue(task, delay_seconds=delay):
+                logger.warning(
+                    "queue.worker.drop_task",
+                    extra={
+                        "task_type": task.task_type,
+                        "attempt": task.attempts,
+                    },
+                )
+        await asyncio.sleep(settings.rq_dispatch_throttle_seconds)
+
+    if processed > 0:
+        logger.info("queue.worker.batch_complete", extra={"count": processed})
+    return processed
+
+
+async def _run_worker_loop() -> None:
+    while True:
+        try:
+            await flush_queue(
+                block=True,
+                block_timeout=0,
+            )
+        except Exception:
+            logger.exception(
+                "queue.worker.loop_failed",
+                extra={"queue_name": settings.rq_queue_name},
+            )
+            await asyncio.sleep(1)
+
+
+def run_worker() -> None:
+    """RQ entrypoint for running continuous queue processing."""
+    logger.info(
+        "queue.worker.batch_started",
+        extra={"throttle_seconds": settings.rq_dispatch_throttle_seconds},
+    )
+    try:
+        asyncio.run(_run_worker_loop())
+    finally:
+        logger.info("queue.worker.stopped", extra={"queue_name": settings.rq_queue_name})

backend/app/services/webhooks/dispatch.py

@@ -17,9 +17,10 @@ from app.models.board_webhook_payloads import BoardWebhookPayload
 from app.models.board_webhooks import BoardWebhook
 from app.models.boards import Board
 from app.services.openclaw.gateway_dispatch import GatewayDispatchService
+from app.services.queue import QueuedTask
 from app.services.webhooks.queue import (
     QueuedInboundDelivery,
-    dequeue_webhook_delivery,
+    decode_webhook_task,
     requeue_if_failed,
 )
 
@@ -163,12 +164,31 @@ async def _process_single_item(item: QueuedInboundDelivery) -> None:
         await session.commit()
 
 
+def _compute_webhook_retry_delay(attempts: int) -> float:
+    base = settings.rq_dispatch_retry_base_seconds * (2 ** max(0, attempts))
+    return min(base, settings.rq_dispatch_retry_max_seconds)
+
+
+def _compute_webhook_retry_jitter(base_delay: float) -> float:
+    return random.uniform(0, min(settings.rq_dispatch_retry_max_seconds / 10, base_delay * 0.1))
+
+
+async def process_webhook_queue_task(task: QueuedTask) -> None:
+    item = decode_webhook_task(task)
+    await _process_single_item(item)
+
+
+def requeue_webhook_queue_task(task: QueuedTask, *, delay_seconds: float = 0) -> bool:
+    payload = decode_webhook_task(task)
+    return requeue_if_failed(payload, delay_seconds=delay_seconds)
+
+
 async def flush_webhook_delivery_queue(*, block: bool = False, block_timeout: float = 0) -> int:
     """Consume queued webhook events and notify board leads in a throttled batch."""
     processed = 0
     while True:
         try:
-            item = dequeue_webhook_delivery(block=block, block_timeout=block_timeout)
+            item = dequeue_webhook_delivery_task(block=block, block_timeout=block_timeout)
         except Exception:
             logger.exception("webhook.dispatch.dequeue_failed")
             continue
@@ -199,11 +219,8 @@ async def flush_webhook_delivery_queue(*, block: bool = False, block_timeout: fl
                     "error": str(exc),
                 },
             )
-            delay = min(
-                settings.rq_dispatch_retry_base_seconds * (2 ** max(0, item.attempts)),
-                settings.rq_dispatch_retry_max_seconds,
-            )
-            jitter = random.uniform(0, min(settings.rq_dispatch_retry_max_seconds / 10, delay * 0.1))
+            delay = _compute_webhook_retry_delay(item.attempts)
+            jitter = _compute_webhook_retry_jitter(delay)
             requeue_if_failed(item, delay_seconds=delay + jitter)
         await asyncio.sleep(settings.rq_dispatch_throttle_seconds)
     if processed > 0:
@@ -211,6 +228,25 @@ async def flush_webhook_delivery_queue(*, block: bool = False, block_timeout: fl
     return processed
 
 
+def dequeue_webhook_delivery_task(
+    *,
+    block: bool = False,
+    block_timeout: float = 0,
+) -> QueuedInboundDelivery | None:
+    """Pop one queued webhook delivery payload."""
+    from app.services.queue import dequeue_task
+
+    task = dequeue_task(
+        settings.rq_queue_name,
+        redis_url=settings.rq_redis_url,
+        block=block,
+        block_timeout=block_timeout,
+    )
+    if task is None:
+        return None
+    return decode_webhook_task(task)
+
+
 def run_flush_webhook_delivery_queue() -> None:
     """RQ entrypoint for running the async queue flush from worker jobs."""
     logger.info(

backend/app/services/webhooks/queue.py

@@ -40,7 +40,7 @@ def _task_from_payload(payload: QueuedInboundDelivery) -> QueuedTask:
     )
 
 
-def _payload_from_task(task: QueuedTask) -> QueuedInboundDelivery:
+def decode_webhook_task(task: QueuedTask) -> QueuedInboundDelivery:
     if task.task_type not in {TASK_TYPE, "legacy"}:
         raise ValueError(f"Unexpected task_type={task.task_type!r}; expected {TASK_TYPE!r}")
 
@@ -107,7 +107,7 @@ def dequeue_webhook_delivery(
         )
         if task is None:
             return None
-        return _payload_from_task(task)
+        return decode_webhook_task(task)
     except Exception as exc:
         logger.error(
             "webhook.queue.dequeue_failed",