connection pool add debug_connection_used, it will print connection l…

…ast query sql when connection not release to poll

tormysql/pool.py

@@ -11,6 +11,7 @@
 from collections import deque
 from tornado.concurrent import Future
 from tornado.ioloop import IOLoop
+from pymysql._compat import text_type
 from .client import Client
 
 
@@ -65,11 +66,43 @@ def do_close(self):
         return super(Connection, self).close()
 
 
+class RecordQueryConnection(Connection):
+    def __init__(self, *args, **kwargs):
+        super(RecordQueryConnection, self).__init__(*args, **kwargs)
+
+        self._last_query_sql = ""
+
+    def connect(self):
+        future = super(RecordQueryConnection, self).connect()
+
+        origin_query = self._connection.query
+        def query(sql, unbuffered=False):
+            self._last_query_sql = sql
+            return origin_query(sql, unbuffered)
+        self._connection.query = query
+
+        return future
+
+    def query(self, sql, unbuffered=False):
+        self._last_query_sql = sql
+        return super(RecordQueryConnection, self).query(sql, unbuffered)
+
+    def get_last_query_sql(self):
+        if isinstance(self._last_query_sql, text_type):
+            return self._last_query_sql.encode("utf-8")
+        return self._last_query_sql
+
+
 class ConnectionPool(object):
     def __init__(self, *args, **kwargs):
         self._max_connections = kwargs.pop("max_connections") if "max_connections" in kwargs else 32
         self._idle_seconds = kwargs.pop("idle_seconds") if "idle_seconds" in kwargs else 7200
         self._wait_connection_timeout = kwargs.pop("wait_connection_timeout") if "wait_connection_timeout" in kwargs else 8
+        self._debug_connection_used = kwargs.pop("debug_connection_used") if "debug_connection_used" in kwargs else False
+        if self._debug_connection_used:
+            self._connection_cls = RecordQueryConnection
+        else:
+            self._connection_cls = Connection
         self._args = args
         self._kwargs = kwargs
         self._connections = deque(maxlen = self._max_connections)
@@ -109,7 +142,7 @@ def connection_connected_callback(self, future, connection_future):
                     IOLoop.current().add_callback(self.init_connection, wait_future)
 
     def init_connection(self, future):
-        connection = Connection(self, *self._args, **self._kwargs)
+        connection = self._connection_cls(self, *self._args, **self._kwargs)
         connection.set_close_callback(self.connection_close_callback)
         connection_future = connection.connect()
         self._connections_count += 1
@@ -265,9 +298,15 @@ def check_idle_connections(self):
         for connection in self._used_connections.values():
             if now - connection.used_time > (self._wait_connection_timeout * 4) ** 2:
                 connection.do_close()
-                logging.error("Connection used timeout close, used time %.2fs %s %s.", now - connection.used_time, connection, self)
+                if self._debug_connection_used:
+                    logging.error("Connection used timeout close, used time %.2fs %s %s.\n%s", now - connection.used_time, connection, self, connection.get_last_query_sql())
+                else:
+                    logging.error("Connection used timeout close, used time %.2fs %s %s.", now - connection.used_time, connection, self)
             elif now - connection.used_time > self._wait_connection_timeout ** 2 * 2:
-                logging.warning("Connection maybe not release, used time %.2fs %s %s.", now - connection.used_time, connection, self)
+                if self._debug_connection_used:
+                    logging.warning("Connection maybe not release, used time %.2fs %s %s.\n%s", now - connection.used_time, connection, self, connection.get_last_query_sql())
+                else:
+                    logging.warning("Connection maybe not release, used time %.2fs %s %s.", now - connection.used_time, connection, self)
 
         next_check_time = now + self._idle_seconds
         for connection in tuple(self._connections):