Cherrypy:处理时间大的页面的解决方案 [英] Cherrypy : which solutions for pages with large processing time
问题描述
我想知道这里会有什么好的解决方案。 >
这里的所有内容都取决于网站的数量。 CherryPy 是一个线程服务器,一旦线程正在等待数据库,新的请求将不被处理。还有方面的请求队列,但一般来说是这样的。
可怜的人的解决方案
如果你知道你有小的流量你可以尝试解决办法。如果需要,增加 response.timeout
(默认为300秒)。增加 server.thread_pool
(默认为10)。如果您使用保留代理,例如 nginx ,在 CherryPy 应用程序之前,也可以增加代理超时。
以下解决方案将需要您重新设计您的网站。特别要使其异步,客户端代码发送任务,然后使用pull或push获取其结果。
CherryPy BackgroundTask
您可以使用 cherrypy.process.plugins .BackgroundTask
和服务器端的一些中间存储(例如数据库中的新表)。用于pull或WebSockets的XmlHttpRequest推送到客户端。请注意,由于CherryPy在单个Python进程中运行,因此后台任务的线程也将在其中运行。
如果您执行一些SQL结果集后处理,您将受到 GIL 的影响。所以你可能需要重写它来使用进程,这是一个更复杂的一个。
工业解决方案
如果您的网站运行或被视为规模经营,您最好考虑一个分布式任务队列,如 Rq 或芹菜。它使服务器端有所不同。客户端是相同的拉或推。
示例
以下是 BackgroundTags
与XHR轮询。
#!/ usr / bin / env python
# - * - 编码:utf-8 - * -
import time
import uuid
import cherrypy
from cherrypy.process.plugins import BackgroundTask
config = {
'global':{
'server.socket_host':'127.0.0.1',
'server.socket_port':8080,
'server.thread_pool':8,
}
}
类App:
_taskResultMap =无
def __init __(self):
self._taskResultMap = {}
def _task(self, id,arg):
time.sleep(10)#long one,right?
self._taskResultMap [id] = 42 + arg
@ cherrypy.expose
@ cherrypy.tools.json_out()
def schedule(self,arg)
id = str(uuid.uuid1())
self._taskResultMap [id] =无
BackgroundTask(1,self._task,(id,int(arg)),bus = cherrypy .engine).start()
return str(id)
@ cherrypy.expose
@ cherrypy.tools.json_out()
def poll(self,id )
if self._taskResultMap [id] is None:
return {'id':id,'status':'wait','result':None}
else:
return {'id':id,'status':'ready','result':self._taskResultMap.pop(id)}
@ cherrypy.expose
def index self):
return'''<!DOCTYPE html>
< html>
< head>
< title> CherryPy BackgroundTask演示< / title>
< script type ='text / javascript'src ='http://cdnjs.cloudflare.com/ajax/libs/qooxdoo/3.5.1/q.min.js'>< / script>
< script type ='text / javascript'>
//不要以这种方式构建你真正的JavaScript应用程序。
//这个回调意大利面只是为了简洁。
函数sendSchedule(arg,callback)
{
var xhr = q.io.xhr('/ schedule?arg ='+ arg);
xhr.on('loadend',function(xhr)
{
if(xhr.status == 200)
{
回调(JSON.parse(xhr) .responseText))
}
});
xhr.send();
};
函数sendPoll(id,callback)
{
var xhr = q.io.xhr('/ poll?id ='+ id);
xhr.on('loadend',function(xhr)
{
if(xhr.status == 200)
{
回调(JSON.parse(xhr) .responseText))
}
});
xhr.send();
}
函数start(event)
{
event.preventDefault();
//传递给任务的示例参数
var arg = Math.round(Math.random()* 100);
sendSchedule(arg,function(id)
{
console.log('scheduled(',arg,')as',id);
q。 create('< li />')
.setAttribute('id',id)
.append(id +':< img src =http://sstatic.net/Img /progress-dots.gif/>')
.appendTo('#result-list');
var poll = function()
{
console.log('polling',id);
sendPoll(id,function(response)
{
console.log('polled',id''''''' ');
if(response.status =='wait')
{
setTimeout(poll,2500);
}
else if(response.status = ='ready')
{
q('#'+ id)
.empty()
.append('< span>'+ id +':42 +'+ arg +'='+ response.result +'< / span>');
}
});
};
setTimeout(poll,2500);
});
}
q.ready(function()
{
q('#run')。on('click',start);
} );
< / script>
< / head>
< body>
< p>< a href ='#'id ='run'>运行长任务< / a>,浏览器控制台。< / p>
< ul id ='result-list'>< / ul>
< / body>
< / html>
''
如果__name__ =='__main__':
cherrypy.quickstart(App(),'/',config)
I have a website powered by cherrypy. For some pages, I need quite a long processing time (a multi-join SQL request on a several-million-row DB). The processing needs sometimes 20 seconds or more, and the browser get crashed because it is too long.
I'm wondering what would be a nice solution here.
Everything here depends on a volume of the website. CherryPy is a threaded server and once every thread is waiting for database, new requests won't be processed. There's also aspect of request queue, but in general it is so.
Poor man's solution
If you know that you have small traffic you can try to workaround. Increase response.timeout
if needed (default is 300 seconds). Increase server.thread_pool
(defaults to 10). If you use reserve proxy, like nginx, in front of CherryPy application, increase proxy timeout there as well.
The following solutions will require you to redesign your website. Specifically to make it asynchronous, where client code sends a task, and then uses pull or push to get its result. It will require changes on both sides of the wire.
CherryPy BackgroundTask
You can make use of cherrypy.process.plugins.BackgroundTask
and some intermediary storage (e.g. new table in your database) at server side. XmlHttpRequest for pull or WebSockets for push to client side. CherryPy can handle both.
Note that because CherryPy is run in single Python process, the background task's thread will run within it too. If you do some SQL result set post-processing, you will be affected by GIL. So you may want rewrite it to use processes instead, which is a little more complicated.
Industrial solution
If your website operates or is deemed to operate at scale, you are better to consider a distributed task queue like Rq or Celery. It makes server-side difference. Client side is the same pull or push.
Example
Here follows a toy implementation for BackgroundTags
with XHR polling.
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import time
import uuid
import cherrypy
from cherrypy.process.plugins import BackgroundTask
config = {
'global' : {
'server.socket_host' : '127.0.0.1',
'server.socket_port' : 8080,
'server.thread_pool' : 8,
}
}
class App:
_taskResultMap = None
def __init__(self):
self._taskResultMap = {}
def _task(self, id, arg):
time.sleep(10) # long one, right?
self._taskResultMap[id] = 42 + arg
@cherrypy.expose
@cherrypy.tools.json_out()
def schedule(self, arg):
id = str(uuid.uuid1())
self._taskResultMap[id] = None
BackgroundTask(1, self._task, (id, int(arg)), bus = cherrypy.engine).start()
return str(id)
@cherrypy.expose
@cherrypy.tools.json_out()
def poll(self, id):
if self._taskResultMap[id] is None:
return {'id': id, 'status': 'wait', 'result': None}
else:
return {'id': id, 'status': 'ready', 'result': self._taskResultMap.pop(id)}
@cherrypy.expose
def index(self):
return '''<!DOCTYPE html>
<html>
<head>
<title>CherryPy BackgroundTask demo</title>
<script type='text/javascript' src='http://cdnjs.cloudflare.com/ajax/libs/qooxdoo/3.5.1/q.min.js'></script>
<script type='text/javascript'>
// Do not structure you real JavaScript application this way.
// This callback spaghetti is only for brevity.
function sendSchedule(arg, callback)
{
var xhr = q.io.xhr('/schedule?arg=' + arg);
xhr.on('loadend', function(xhr)
{
if(xhr.status == 200)
{
callback(JSON.parse(xhr.responseText))
}
});
xhr.send();
};
function sendPoll(id, callback)
{
var xhr = q.io.xhr('/poll?id=' + id);
xhr.on('loadend', function(xhr)
{
if(xhr.status == 200)
{
callback(JSON.parse(xhr.responseText))
}
});
xhr.send();
}
function start(event)
{
event.preventDefault();
// example argument to pass to the task
var arg = Math.round(Math.random() * 100);
sendSchedule(arg, function(id)
{
console.log('scheduled (', arg, ') as', id);
q.create('<li/>')
.setAttribute('id', id)
.append(id + ': <img src="http://sstatic.net/Img/progress-dots.gif" />')
.appendTo('#result-list');
var poll = function()
{
console.log('polling', id);
sendPoll(id, function(response)
{
console.log('polled', id, '(', response, ')');
if(response.status == 'wait')
{
setTimeout(poll, 2500);
}
else if(response.status == 'ready')
{
q('#' + id)
.empty()
.append('<span>' + id + ': 42 + ' + arg + ' = ' + response.result + '</span>');
}
});
};
setTimeout(poll, 2500);
});
}
q.ready(function()
{
q('#run').on('click', start);
});
</script>
</head>
<body>
<p><a href='#' id='run'>Run a long task</a>, look in browser console.</p>
<ul id='result-list'></ul>
</body>
</html>
'''
if __name__ == '__main__':
cherrypy.quickstart(App(), '/', config)
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