Broaden exception scope around connection creation in Pool

Extension of 662546f
* Added `InternalError` to possible exceptions as it is
raised in case of error codes not mapped to specific
exceptions.
* Added SERVER_SHUTDOWN to operational errors

Author: Krzysztof Mioduszewski

tornado_mysql/err.py

@@ -87,7 +87,7 @@ def _map_error(exc, *errors):
            ER.NOT_SUPPORTED_YET, ER.FEATURE_DISABLED, ER.UNKNOWN_STORAGE_ENGINE)
 _map_error(OperationalError, ER.DBACCESS_DENIED_ERROR, ER.ACCESS_DENIED_ERROR,
            ER.CON_COUNT_ERROR, ER.TABLEACCESS_DENIED_ERROR,
-           ER.COLUMNACCESS_DENIED_ERROR)
+           ER.COLUMNACCESS_DENIED_ERROR, ER.SERVER_SHUTDOWN)
 
 del _map_error, ER
 

tornado_mysql/pools.py

@@ -11,7 +11,7 @@
 
 from tornado_mysql import connect
 from tornado_mysql.connections import Connection
-from tornado_mysql.err import OperationalError
+from tornado_mysql.err import OperationalError, InternalError
 
 
 log = logging.getLogger("tornado_mysql.pools")
@@ -123,7 +123,7 @@ def execute(self, query, params=None, cursor=None):
         """
         try:
             conn = yield self._get_conn()
-        except OperationalError:
+        except (OperationalError, InternalError):
             self._after_close()
             raise
 
@@ -149,7 +149,7 @@ def begin(self):
         """
         try:
             conn = yield self._get_conn()
-        except OperationalError:
+        except (OperationalError, InternalError):
             self._after_close()
             raise