Python 龙卷风&x2B;莫莫科。重新启动损坏的连接
我们使用的是tornado 3.2+momoko 1.1+pgpool 重启pgpool后-我们必须重启tornado 如果我们不重新启动tornado-我们会出现如下错误:Python 龙卷风&x2B;莫莫科。重新启动损坏的连接,python,django,tornado,psycopg2,momoko,Python,Django,Tornado,Psycopg2,Momoko,我们使用的是tornado 3.2+momoko 1.1+pgpool 重启pgpool后-我们必须重启tornado 如果我们不重新启动tornado-我们会出现如下错误: [E 140322 19:23:32 web:1305] Uncaught exception POST /api/user/balance/ (127.0.0.1) HTTPRequest(protocol='http', host='127.0.0.1:3001', method='POST', uri='/a
[E 140322 19:23:32 web:1305] Uncaught exception POST /api/user/balance/ (127.0.0.1)
HTTPRequest(protocol='http', host='127.0.0.1:3001', method='POST', uri='/api/user/balance/', version='HTTP/1.0', remote_ip='127.0.0.1', headers={'Host': '127.0.0.1:3001', 'Connection': 'close', 'Content-Type': 'application/x-www-form-urlencoded', 'Content-Length': '55', 'Accept-Encoding': 'gzip'})
Traceback (most recent call last):
File "/projects/application_new/env/lib/python2.7/site-packages/tornado/web.py", line 1192, in _stack_context_handle_exception
raise_exc_info((type, value, traceback))
File "/projects/application_new/env/lib/python2.7/site-packages/tornado/web.py", line 1375, in wrapper
result = method(self, *args, **kwargs)
File "api_server.py", line 435, in post
UserBalanceForJSON(self.db, user_id=user_id).results(self.json_callback)
File "/projects/application_new/env/lib/python2.7/site-packages/tornado/gen.py", line 159, in wrapper
runner.run()
File "/projects/application_new/env/lib/python2.7/site-packages/tornado/gen.py", line 529, in run
yielded = self.gen.throw(*exc_info)
File "/projects/application_new/api/models/orm.py", line 16, in results
result = yield momoko.Op(self.db.execute, sql, [])
File "/projects/application_new/env/lib/python2.7/site-packages/tornado/gen.py", line 520, in run
next = self.yield_point.get_result()
File "/projects/application_new/env/lib/python2.7/site-packages/momoko/utils.py", line 41, in get_result
raise error
ProgrammingError: execute cannot be used while an asynchronous query is underway
我发现django用户在使用Greenlet时也有同样的问题
如何避免这种情况而不重启龙卷风 临时解决方案-如果连接出错,请关闭连接。为此,让我们以
momoko.Op
为灵感创建一个类:
class OpWithFallback(gen.Task):
"""
Run a single asynchronous operation.
Behaves like `tornado.gen.Task`_, but raises an exception (one of Psycop2's
exceptions_) when an error occurs related to Psycopg2 or PostgreSQL.
Closes connection with error.
.. _exceptions: http://initd.org/psycopg/docs/module.html#exceptions
.. _tornado.gen.Task: http://www.tornadoweb.org/documentation/gen.html#tornado.gen.Task
"""
def get_result(self):
(result, error), _ = super(OpWithFallback, self).get_result()
if error:
self.fallback(error, result)
return result
def fallback(self, error, result):
log.warning('Closing dead connection or connection with idle transaction: %s' % result.connection)
result.connection.close()
raise error
让我们像这样使用它:
result = yield OpWithFallback(self.db.execute, sql, [])
我们应该这样初始化数据库:
self.db=momoko.Pool('dbname=dbname host=127.0.0.1 port=9999',raise\u connect\u errors=False)
。使用127.0.0.1
而不是localhost
,并将raise\u connect\u erros
设置为False,否则您可能无法重新连接数据库。警告和关闭语句应使用try-catch包装,在某些情况下,结果为None