python龍旋風圖形代碼_python – 龍卷風momoko不處理連接配接

我使用tornado(4.2.1)momoko(2.2.0)psycopg2(2.6.1)用于小型Web應用程式,它可以工作,直到PostgreSQL伺服器關閉連接配接.然後在每個db.execute()指令後,我收到一條錯誤消息：

Traceback (most recent call last):

File "C:\Python27\lib\site-packages\tornado-4.2.1-py2.7-win32.egg\tornado\web.py", line 1415, in _execute

result = yield result

File "C:\Python27\lib\site-packages\tornado-4.2.1-py2.7-win32.egg\tornado\gen.py", line 870, in run

value = future.result()

File "C:\Python27\lib\site-packages\tornado-4.2.1-py2.7-win32.egg\tornado\concurrent.py", line 215, in result

raise_exc_info(self._exc_info)

File "C:\Python27\lib\site-packages\tornado-4.2.1-py2.7-win32.egg\tornado\gen.py", line 876, in run

yielded = self.gen.throw(*exc_info)

File "server.py", line 63, in get

cursor = yield self.db.execute(query)

File "C:\Python27\lib\site-packages\tornado-4.2.1-py2.7-win32.egg\tornado\gen.py", line 870, in run

value = future.result()

File "C:\Python27\lib\site-packages\tornado-4.2.1-py2.7-win32.egg\tornado\concurrent.py", line 215, in result

raise_exc_info(self._exc_info)

File "D:\work\program-stat\momoko\connection.py", line 453, in when_available

future_or_result = method(conn, *args, **kwargs)

File "D:\work\program-stat\momoko\connection.py", line 743, in execute

cursor.execute(operation, parameters)

File "C:\Python27\lib\site-packages\psycopg2\extras.py", line 288, in execute

return super(NamedTupleCursor, self).execute(query, vars)

OperationalError: server closed the connection unexpectedly

This probably means the server terminated abnormally

before or while processing the request.

這是一個代碼：

import os

import tornado.httpserver

import tornado.ioloop

import tornado.options

import tornado.web

import momoko

from tornadotools.route import Route

from psycopg2.extras import NamedTupleCursor

import environments as env

tornado.options.define("port", default=9999, help="run on the given port", type=int)

tornado.options.define("pgsql_host", default=env.DB_HOST, help="database host")

tornado.options.define("pgsql_database", default=env.DB_DATABASE, help="database name")

tornado.options.define("pgsql_user", default=env.DB_LOGIN, help="database user")

tornado.options.define("pgsql_password", default=env.DB_PASSWORD, help="database password")

class Application(tornado.web.Application):

def __init__(self):

handlers = Route.routes()

settings = dict(

template_path=os.path.join(os.path.dirname(__file__), "templates"),

static_path=os.path.join(os.path.dirname(__file__), "static"),

debug=True,

)

tornado.web.Application.__init__(self, handlers, **settings)

# Have one global connection to DB across all handlers

self.db = momoko.Pool(

dsn='dbname=%s user=%s password=%s '

'host=%s port=5432' % (

tornado.options.options.pgsql_database,

tornado.options.options.pgsql_user,

tornado.options.options.pgsql_password,

tornado.options.options.pgsql_host),

cursor_factory=NamedTupleCursor,

)

self.db.connect()

class BaseHandler(tornado.web.RequestHandler):

@property

def db(self):

return self.application.db

@Route(r"/")

class HomeHandler(BaseHandler):

def get(self):

self.write("

• ")

self.write("

Test page")

self.write("

")

self.finish()

@Route(r"/test")

class MogrifyHandler(BaseHandler):

@tornado.web.asynchronous

@tornado.gen.coroutine

def get(self):

cursor = yield self.db.execute("SELECT %s as t;", (1,))

self.render("test.html", result=cursor.fetchall())

def main():

tornado.options.parse_command_line()

http_server = tornado.httpserver.HTTPServer(Application())

http_server.listen(tornado.options.options.port)

tornado.ioloop.IOLoop.instance().start()

if __name__ == "__main__":

main()

如何在不重新啟動應用程式的情況下自動處理此異常并重新連接配接到資料庫？