limit max pool connection. fixed sacrud/pyramid_sacrud#121

example/development.ini

@@ -11,3 +11,38 @@ ps_alchemy.items_per_page = 6
 use = egg:waitress#main
 host = 0.0.0.0
 port = 6543
+
+###
+# logging configuration
+# http://docs.pylonsproject.org/projects/pyramid/en/1.6-branch/narr/logging.html
+###
+
+[loggers]
+keys = root, sqlalchemy
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = INFO
+handlers = console
+
+[logger_sqlalchemy]
+level = INFO
+handlers =
+qualname = sqlalchemy.engine
+# "level = INFO" logs SQL queries.
+# "level = DEBUG" logs SQL queries and results.
+# "level = WARN" logs neither.  (Recommended for production systems.)
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(asctime)s %(levelname)-5.5s [%(name)s:%(lineno)s][%(threadName)s] %(message)s

ps_alchemy/resources.py

@@ -83,15 +83,18 @@ def ps_crud(self):
 
     @property
     def dbsession(self):
-        return self._dbsession or self._default_dbsession
+        if not self._dbsession:
+            self._dbsession = self._default_dbsession
+        return self._dbsession
 
     @dbsession.setter
     def dbsession(self, dbsession):
         self._dbsession = dbsession
 
     @property
     def _default_dbsession(self):
-        engine = sqlalchemy.engine_from_config(get_current_registry().settings)
+        registry = get_current_registry()
+        engine = sqlalchemy.engine_from_config(registry.settings)
         session = scoped_session(
             sessionmaker(extension=ZopeTransactionExtension())
         )
@@ -247,4 +250,3 @@ def __getitem__(self, name):
 class MassActionResource(BaseResource):
 
     __name__ = 'mass_action'
-