Fix healthcheck with separate session

Bugfix/backend timeout infinite

lib/backend.py

@@ -11,7 +11,7 @@ from functools import cached_property
 from distutils.util import strtobool
 
 from anyio import open_file
-from aiohttp import web, ClientResponse, ClientSession, ClientConnectorError
+from aiohttp import web, ClientResponse, ClientSession, ClientConnectorError, ClientTimeout, TCPConnector
 
 import requests
 from Crypto.Signature import pkcs1_15
@@ -75,7 +75,13 @@ class Backend:
     @cached_property
     def session(self):
         log.debug(f"starting session with {self.model_server_url}")
-        return ClientSession(self.model_server_url)
+        connector = TCPConnector(
+            force_close=True, # Required for long running jobs
+            enable_cleanup_closed=True,
+        )
+        
+        timeout = ClientTimeout(total=None)
+        return ClientSession(self.model_server_url, timeout=timeout, connector=connector)
 
     def create_handler(
         self,
@@ -184,18 +190,30 @@ class Backend:
             log.debug(f"Exception in main handler loop {e}")
             return web.Response(status=500)
 
+    @cached_property  
+    def healthcheck_session(self):
+        """Dedicated session for healthchecks to avoid conflicts with API session"""
+        log.debug("creating dedicated healthcheck session")
+        connector = TCPConnector(
+            force_close=True,  # Keep this for isolation
+            enable_cleanup_closed=True,
+        )
+        timeout = ClientTimeout(total=10)  # Reasonable timeout for healthchecks
+        return ClientSession(timeout=timeout, connector=connector)
+
     async def __healthcheck(self):
         health_check_url = self.benchmark_handler.healthcheck_endpoint
         if health_check_url is None:
             log.debug("No healthcheck endpoint defined, skipping healthcheck")
             return
+
         while True:
             await sleep(10)
             if self.__start_healthcheck is False:
                 continue
             try:
                 log.debug(f"Performing healthcheck on {health_check_url}")
-                async with self.session.get(health_check_url) as response:
+                async with self.healthcheck_session.get(health_check_url) as response:
                     if response.status == 200:
                         log.debug("Healthcheck successful")
                     elif response.status == 503:
@@ -204,7 +222,6 @@ class Backend:
                             f"Healthcheck failed with status: {response.status}"
                         )
                     else:
-                        # endpoint not ready yet so bail
                         log.debug(f"Healthcheck Endpoint not ready: {response.status}")
             except Exception as e:
                 log.debug(f"Healthcheck failed with exception: {e}")