Fix ResourceLogger blocking main thread

backend/danswer/background/indexing/dask_utils.py

@@ -1,4 +1,4 @@
-import time
+import asyncio
 
 import psutil
 from dask.distributed import WorkerPlugin
@@ -18,13 +18,16 @@ def setup(self, worker: Worker) -> None:
         self.worker = worker
         worker.loop.add_callback(self.log_resources)
 
-    def log_resources(self) -> None:
-        """Periodically log CPU and memory usage."""
+    async def log_resources(self) -> None:
+        """Periodically log CPU and memory usage.
+
+        NOTE: must be async or else will clog up the worker indefinitely due to the fact that
+        Dask uses Tornado under the hood (which is async)"""
         while True:
             cpu_percent = psutil.cpu_percent(interval=None)
             memory_available_gb = psutil.virtual_memory().available / (1024.0**3)
             # You can now log these values or send them to a monitoring service
             logger.debug(
                 f"Worker {self.worker.address}: CPU usage {cpu_percent}%, Memory available {memory_available_gb}GB"
             )
-            time.sleep(self.log_interval)
+            await asyncio.sleep(self.log_interval)