tornado | 易学教程

The proper way to scale python tornado application

阅读更多关于 The proper way to scale python tornado application

问题 I am searching for some way to scale one instance of tornado application to many. I have 5 servers and want to run at each 4 instances of application. The main issue I don't know how to resolve - is to make communication between instances in right way. I see next approaches to make it: Use memcached for sharing data. I don't think this approach is good, because much traffic would go to server with memcached. Therefore in the future there can be trafic-related issues. Open sockets between each

tornado web http request blocks other requests, how to not block other requests

阅读更多关于 tornado web http request blocks other requests, how to not block other requests

问题 import tornado.web import Queue QUEUE = Queue.Queue() class HandlerA( tornado.web.RequestHandler ): def get(self): global QUEUE self.finish(QUEUE.get_nowait()) class HandlerB( tornado.web.RequestHandler ): def get(self): global QUEUE QUEUE.put('Hello') self.finish('In queue.') Problem: HandlerA blocks HandlerB for 10 seconds. Browser A handled by HandlerA and waits... Browser B handled by HandlerB and waits.... till timeout exceptions Goal Browser A handled by HandlerA and waits... Browser B

Tornado—options.define()方法与options.options解读

阅读更多关于 Tornado—options.define()方法与options.options解读

https://www.cnblogs.com/renfanzi/p/9585167.html https://www.jianshu.com/p/ec17650059c9 # -*- coding:utf-8 -*- import tornado.web # web服务 import tornado.ioloop # I/O 时间循环 import tornado.httpserver # 新引入httpserver模块，单线程的http服务 from tornado.options import define, options define("ip", default="", help="run on the given ip", type=str) define("port", default=8066, type=int, help="run on the given port") define("domain", default=[], type=str, help="run on the given domain", multiple=True) class Mainhandler(tornado.web.RequestHandler): def get(self): self.write("hello world!") app = tornado.web

Tornado custom error handler for Static file

阅读更多关于 Tornado custom error handler for Static file

问题 How can I show custom 404 error page for static files? in my current application handler I have added last pattern as follows [ (r'/(favicon.ico)', tornado.web.StaticFileHandler, {"path": mypath}), (r'/foo',FooHandler), (r'/bar',BarHandler), (r'/(.*)',ErrorHandler), ] and this is my error handler class ErrorHandler(BaseHandler): def get(self,d): self.status_code = 404 self.show404(d) If I visit http://localhost/abc I am getting my custom 404 page but if I try to get http://localhost/static

Is it possible to get values from query string with same name?

阅读更多关于 Is it possible to get values from query string with same name?

问题 I want to know if it's possible to get values from this query string? '?agencyID=1&agencyID=2&agencyID=3' Why I have to use a query string like this? I have a form with 10 check boxes. my user should send me ID of news agencies which he/she is interested in. so to query string contains of multiple values with the same name. total count of news agencies are variable and they are loaded from database. I'm using Python Tornado to parse query strings. 回答1: Reading the tornado docs, this seems to

Tornado—IOLoop.instance()方法和IOLoop.current()方法区别

阅读更多关于 Tornado—IOLoop.instance()方法和IOLoop.current()方法区别

https://www.cnblogs.com/lucky-heng/p/10152995.html 来源： https://www.cnblogs.com/liuhaidon/p/12017508.html

tornado: AsyncHttpClient.fetch from an iterator?

阅读更多关于 tornado: AsyncHttpClient.fetch from an iterator?

问题 I'm trying to write a web crawler thing and want to make HTTP requests as quickly as possible. tornado's AsyncHttpClient seems like a good choice, but all the example code I've seen (e.g. https://stackoverflow.com/a/25549675/1650177) basically call AsyncHttpClient.fetch on a huge list of URLs to let tornado queue them up and eventually make the requests. But what if I want to process an indefinitely long (or just a really big) list of URLs from a file or the network? I don't want to load all

Tornado—三种启动tornado的方式

阅读更多关于 Tornado—三种启动tornado的方式

第一种启动方式 import tornado.web # web服务 import tornado.ioloop # I/O 时间循环 class Mainhandler(tornado.web.RequestHandler): def get(self): self.write("hello world!") # 建立路由表 app = tornado.web.Application([ (r"/index", Mainhandler), ]) if __name__ == "__main__": app.listen(8000) # 监听端口 # tornado.ioloop.IOLoop.current().start() tornado.ioloop.IOLoop.instance().start() # 开始事件 app.listen()这个方法只能在单进程模式中使用。对于app.listen()与方式二中的手动创建HTTPServer实例这两种方式，建议大家先使用后者即创建HTTPServer实例的方式，因为其对于理解tornado web应用工作流程的完整性有帮助，便于大家记忆tornado开发的模块组成和程序结构；在熟练使用后，可以改为简写。第二种启动方式：单进程 import tornado.web # web服务 import tornado.ioloop

Tornado Interrupted system call

阅读更多关于 Tornado Interrupted system call

问题 I'm getting this error from time to time and not sure how can be debugged. Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/tornado/ioloop.py", line 662, in start event_pairs = self._impl.poll(poll_timeout) IOError: [Errno 4] Interrupted system call Does anyone know what this means / when is happening? I'm using python 2.7 and tornado 3.2.1 Update: This code is in ioloop.py try: event_pairs = self._impl.poll(poll_timeout) except Exception as e: # Depending on python

Generate large file and send it

阅读更多关于 Generate large file and send it

问题 I have a rather large .csv file (up to 1 million lines) that I want to generate and send when a browser requests it. The current code I have is (except that I don't actually generate the same data): class CSVHandler(tornado.web.RequestHandler): def get(self): self.set_header('Content-Type','text/csv') self.set_header('content-Disposition','attachement; filename=dump.csv') self.write('lineNumber,measure\r\n') # File header for line in range(0,1000000): self.write(','.join([str(line),random