Added current task into task executor's hearbeat (#3444)

### What problem does this PR solve?

Added current task into task executor's hearbeat

### Type of change

- [x] Refactoring

rag/svr/task_executor.py

 CONSUMER_NAME = "task_consumer_" + CONSUMER_NO
 PAYLOAD: Payload | None = None
 BOOT_AT = datetime.now().isoformat()
-DONE_TASKS = 0
-FAILED_TASKS = 0
 PENDING_TASKS = 0
 LAG_TASKS = 0
 
+mt_lock = threading.Lock()
+DONE_TASKS = 0
+FAILED_TASKS = 0
+CURRENT_TASK = None
+
 
 def set_progress(task_id, from_page=0, to_page=-1, prog=None, msg="Processing..."):
     global PAYLOAD
         return None
 
     if TaskService.do_cancel(msg["id"]):
-        DONE_TASKS += 1
+        with mt_lock:
+            DONE_TASKS += 1
         logging.info("Task {} has been canceled.".format(msg["id"]))
         return None
     task = TaskService.get_task(msg["id"])
     if not task:
-        DONE_TASKS += 1
+        with mt_lock:
+            DONE_TASKS += 1
         logging.warning("{} empty task!".format(msg["id"]))
         return None
 
 
 
 def handle_task():
-    global PAYLOAD, DONE_TASKS, FAILED_TASKS
+    global PAYLOAD, mt_lock, DONE_TASKS, FAILED_TASKS, CURRENT_TASK
     task = collect()
     if task:
         try:
             logging.info(f"handle_task begin for task {json.dumps(task)}")
+            with mt_lock:
+                CURRENT_TASK = copy.deepcopy(task)
             do_handle_task(task)
-            DONE_TASKS += 1
-            logging.exception(f"handle_task done for task {json.dumps(task)}")
+            with mt_lock:
+                DONE_TASKS += 1
+                CURRENT_TASK = None
+            logging.info(f"handle_task done for task {json.dumps(task)}")
         except Exception:
-            FAILED_TASKS += 1
+            with mt_lock:
+                FAILED_TASKS += 1
+                CURRENT_TASK = None
             logging.exception(f"handle_task got exception for task {json.dumps(task)}")
     if PAYLOAD:
         PAYLOAD.ack()
 
 
 def report_status():
-    global CONSUMER_NAME, BOOT_AT, DONE_TASKS, FAILED_TASKS, PENDING_TASKS, LAG_TASKS
+    global CONSUMER_NAME, BOOT_AT, PENDING_TASKS, LAG_TASKS, mt_lock, DONE_TASKS, FAILED_TASKS, CURRENT_TASK
     REDIS_CONN.sadd("TASKEXE", CONSUMER_NAME)
     while True:
         try:
                 PENDING_TASKS = int(group_info["pending"])
                 LAG_TASKS = int(group_info["lag"])
 
-            heartbeat = json.dumps({
-                "name": CONSUMER_NAME,
-                "now": now.isoformat(),
-                "boot_at": BOOT_AT,
-                "done": DONE_TASKS,
-                "failed": FAILED_TASKS,
-                "pending": PENDING_TASKS,
-                "lag": LAG_TASKS,
-            })
+            with mt_lock:
+                heartbeat = json.dumps({
+                    "name": CONSUMER_NAME,
+                    "now": now.isoformat(),
+                    "boot_at": BOOT_AT,
+                    "pending": PENDING_TASKS,
+                    "lag": LAG_TASKS,
+                    "done": DONE_TASKS,
+                    "failed": FAILED_TASKS,
+                    "current": CURRENT_TASK,
+                })
             REDIS_CONN.zadd(CONSUMER_NAME, heartbeat, now.timestamp())
             logging.info(f"{CONSUMER_NAME} reported heartbeat: {heartbeat}")
 
         time.sleep(30)
 
 def main():
+    settings.init_settings()
     background_thread = threading.Thread(target=report_status)
     background_thread.daemon = True
     background_thread.start()