Improve task executor heartbeat handling and cleanup (#12390)

Improve task executor heartbeat handling and cleanup.

### What problem does this PR solve?

- **Reduce lock contention during executor cleanup**: The cleanup lock
is acquired only when removing expired executors, not during regular
heartbeat reporting, reducing potential lock contention.

- **Optimize own heartbeat cleanup**: Each executor removes its own
expired heartbeat using `zremrangebyscore` instead of `zcount` +
`zpopmin`, reducing Redis operations and improving efficiency.

- **Improve cleanup of other executors' heartbeats**: Expired executors
are detected by checking their latest heartbeat, and stale entries are
removed safely.

- **Other improvements**: IP address and PID are captured once at
startup, and unnecessary global declarations are removed.

### Type of change

- [x] Performance Improvement

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

rag/svr/task_executor.py

@@ -1188,56 +1188,80 @@ async def get_server_ip() -> str:
 
 
 async def report_status():
-    global CONSUMER_NAME, BOOT_AT, PENDING_TASKS, LAG_TASKS, DONE_TASKS, FAILED_TASKS
+    """
+    Periodically reports the executor's heartbeat
+    """
+    global PENDING_TASKS, LAG_TASKS, DONE_TASKS, FAILED_TASKS
+
+    ip_address = await get_server_ip()
+    pid = os.getpid()
+
+    # Register the executor in Redis
     REDIS_CONN.sadd("TASKEXE", CONSUMER_NAME)
     redis_lock = RedisDistributedLock("clean_task_executor", lock_value=CONSUMER_NAME, timeout=60)
-    while True:
-        try:
-            now = datetime.now()
-            group_info = REDIS_CONN.queue_info(settings.get_svr_queue_name(0), SVR_CONSUMER_GROUP_NAME)
-            if group_info is not None:
-                PENDING_TASKS = int(group_info.get("pending", 0))
-                LAG_TASKS = int(group_info.get("lag", 0))
 
-            pid = os.getpid()
-            ip_address = await get_server_ip()
-            current = copy.deepcopy(CURRENT_TASKS)
-            heartbeat = json.dumps({
-                "ip_address": ip_address,
-                "pid": pid,
-                "name": CONSUMER_NAME,
-                "now": now.astimezone().isoformat(timespec="milliseconds"),
-                "boot_at": BOOT_AT,
-                "pending": PENDING_TASKS,
-                "lag": LAG_TASKS,
-                "done": DONE_TASKS,
-                "failed": FAILED_TASKS,
-                "current": current,
-            })
-            REDIS_CONN.zadd(CONSUMER_NAME, heartbeat, now.timestamp())
+    while True:
+        now = datetime.now()
+        now_ts = now.timestamp()
+
+        group_info = REDIS_CONN.queue_info(settings.get_svr_queue_name(0), SVR_CONSUMER_GROUP_NAME) or {}
+        PENDING_TASKS = int(group_info.get("pending", 0))
+        LAG_TASKS = int(group_info.get("lag", 0))
+
+        current = copy.deepcopy(CURRENT_TASKS)
+        heartbeat = json.dumps({
+            "ip_address": ip_address,
+            "pid": pid,
+            "name": CONSUMER_NAME,
+            "now": now.astimezone().isoformat(timespec="milliseconds"),
+            "boot_at": BOOT_AT,
+            "pending": PENDING_TASKS,
+            "lag": LAG_TASKS,
+            "done": DONE_TASKS,
+            "failed": FAILED_TASKS,
+            "current": current,
+        })
+
+        # Report heartbeat to Redis
+        try:
+            REDIS_CONN.zadd(CONSUMER_NAME, heartbeat, now_ts)
+        except Exception as e:
+            logging.warning(f"Failed to report heartbeat: {e}")
+        else:
             logging.info(f"{CONSUMER_NAME} reported heartbeat: {heartbeat}")
 
-            expired = REDIS_CONN.zcount(CONSUMER_NAME, 0, now.timestamp() - 60 * 30)
-            if expired > 0:
-                REDIS_CONN.zpopmin(CONSUMER_NAME, expired)
-
-            # clean task executor
-            if redis_lock.acquire():
-                task_executors = REDIS_CONN.smembers("TASKEXE")
-                for consumer_name in task_executors:
-                    if consumer_name == CONSUMER_NAME:
-                        continue
-                    expired = REDIS_CONN.zcount(
-                        consumer_name, now.timestamp() - WORKER_HEARTBEAT_TIMEOUT, now.timestamp() + 10
-                    )
-                    if expired == 0:
-                        logging.info(f"{consumer_name} expired, removed")
-                        REDIS_CONN.srem("TASKEXE", consumer_name)
-                        REDIS_CONN.delete(consumer_name)
+        # Clean up own expired heartbeat
+        try:
+            REDIS_CONN.zremrangebyscore(CONSUMER_NAME, 0, now_ts - 60 * 30)
         except Exception as e:
-            logging.exception(f"report_status got exception: {e}")
-        finally:
-            redis_lock.release()
+            logging.warning(f"Failed to clean heartbeat: {e}")
+
+        # Clean other executors
+        lock_acquired = False
+        try:
+            lock_acquired = redis_lock.acquire()
+        except Exception as e:
+            logging.warning(f"Failed to acquire Redis lock: {e}")
+        if lock_acquired:
+            try:
+                task_executors = REDIS_CONN.smembers("TASKEXE") or set()
+                for worker_name in task_executors:
+                    if worker_name == CONSUMER_NAME:
+                        continue
+                    try:
+                        last_heartbeat = REDIS_CONN.REDIS.zrevrange(worker_name, 0, 0, withscores=True)
+                    except Exception as e:
+                        logging.warning(f"Failed to read zset for {worker_name}: {e}")
+                        continue
+
+                    if not last_heartbeat or now_ts - last_heartbeat[0][1] > WORKER_HEARTBEAT_TIMEOUT:
+                        logging.info(f"{worker_name} expired, removed")
+                        REDIS_CONN.srem("TASKEXE", worker_name)
+                        REDIS_CONN.delete(worker_name)
+            except Exception as e:
+                logging.warning(f"Failed to clean other executors: {e}")
+            finally:
+                redis_lock.release()
         await asyncio.sleep(30)
 
 

rag/utils/redis_conn.py

@@ -273,6 +273,17 @@ class RedisDB:
             self.__open__()
         return None
 
+    def zremrangebyscore(self, key: str, min: float, max: float):
+        try:
+            res = self.REDIS.zremrangebyscore(key, min, max)
+            return res
+        except Exception as e:
+            logging.warning(
+                f"RedisDB.zremrangebyscore {key} got exception: {e}"
+            )
+            self.__open__()
+        return 0
+
     def incrby(self, key: str, increment: int):
         return self.REDIS.incrby(key, increment)