Merge pull request #815 from yunstanford/master

add graceful timeout when shutdown

sanic/app.py

@@ -701,7 +701,8 @@ class Sanic:
             'backlog': backlog,
             'has_log': has_log,
             'websocket_max_size': self.config.WEBSOCKET_MAX_SIZE,
-            'websocket_max_queue': self.config.WEBSOCKET_MAX_QUEUE
+            'websocket_max_queue': self.config.WEBSOCKET_MAX_QUEUE,
+            'graceful_shutdown_timeout': self.config.GRACEFUL_SHUTDOWN_TIMEOUT
         }
 
         # -------------------------------------------- #

sanic/config.py

@@ -127,6 +127,7 @@ class Config(dict):
         self.KEEP_ALIVE = keep_alive
         self.WEBSOCKET_MAX_SIZE = 2 ** 20  # 1 megabytes
         self.WEBSOCKET_MAX_QUEUE = 32
+        self.GRACEFUL_SHUTDOWN_TIMEOUT = 15.0  # 15 sec
 
         if load_env:
             self.load_environment_vars()

sanic/server.py

@@ -380,6 +380,14 @@ class HttpProtocol(asyncio.Protocol):
             return True
         return False
 
+    def close(self):
+        """
+        Force close the connection.
+        """
+        if self.transport is not None:
+            self.transport.close()
+            self.transport = None
+
 
 def update_current_time(loop):
     """Cache the current time, since it is needed at the end of every
@@ -412,7 +420,8 @@ def serve(host, port, request_handler, error_handler, before_start=None,
           register_sys_signals=True, run_async=False, connections=None,
           signal=Signal(), request_class=None, has_log=True, keep_alive=True,
           is_request_stream=False, router=None, websocket_max_size=None,
-          websocket_max_queue=None, state=None):
+          websocket_max_queue=None, state=None,
+          graceful_shutdown_timeout=15.0):
     """Start asynchronous HTTP Server on an individual process.
 
     :param host: Address to host on
@@ -525,8 +534,26 @@ def serve(host, port, request_handler, error_handler, before_start=None,
         for connection in connections:
             connection.close_if_idle()
 
-        while connections:
+        # Gracefully shutdown timeout.
+        # We should provide graceful_shutdown_timeout,
+        # instead of letting connection hangs forever.
+        # Let's roughly calcucate time.
+        start_shutdown = 0
+        while connections and (start_shutdown < graceful_shutdown_timeout):
             loop.run_until_complete(asyncio.sleep(0.1))
+            start_shutdown = start_shutdown + 0.1
+
+        # Force close non-idle connection after waiting for
+        # graceful_shutdown_timeout
+        coros = []
+        for conn in connections:
+            if hasattr(conn, "websocket") and conn.websocket:
+                coros.append(conn.websocket.close_connection(force=True))
+            else:
+                conn.close()
+
+        _shutdown = asyncio.gather(*coros, loop=loop)
+        loop.run_until_complete(_shutdown)
 
         trigger_events(after_stop, loop)
 

sanic/worker.py

@@ -91,8 +91,24 @@ class GunicornWorker(base.Worker):
             for conn in self.connections:
                 conn.close_if_idle()
 
-            while self.connections:
+            # gracefully shutdown timeout
+            start_shutdown = 0
+            graceful_shutdown_timeout = self.cfg.graceful_timeout
+            while self.connections and \
+                    (start_shutdown < graceful_shutdown_timeout):
                 await asyncio.sleep(0.1)
+                start_shutdown = start_shutdown + 0.1
+
+            # Force close non-idle connection after waiting for
+            # graceful_shutdown_timeout
+            coros = []
+            for conn in self.connections:
+                if hasattr(conn, "websocket") and conn.websocket:
+                    coros.append(conn.websocket.close_connection(force=True))
+                else:
+                    conn.close()
+            _shutdown = asyncio.gather(*coros, loop=self.loop)
+            await _shutdown
 
     async def _run(self):
         for sock in self.sockets: