我有一个Tornado Websocket服务器，我想在30分钟不活动后超时。我使用self.close()在30分钟不活动后关闭连接。但似乎有些连接在关闭之后仍然保持打开状态。在
 
打开连接：class WebSocketHandler(tornado.websocket.WebSocketHandler):
 
def open(self, *args):
 
self.id = self.generate_id()
 
self.stream.set_nodelay(True)
 
# ... DO STUFF ...
 
self.ini_time = datetime.now()
 
self.message_number = 0
 
self.last_message_time = self.ini_time
 
self.write_message("Connection SUCCESSFUL! Thanks for connecting! Your connection ID is: %d :)" % self.id)
 
self.timeout = tornado.ioloop.IOLoop.current().add_timeout(timedelta(minutes=30), self.force_close)
 
print datetime.now()
 
print "New connection. ID: %d" % self.id
 
print "Total number of open connections: %d" % len(clients)
 
收到信息时：
 
^{pr2}$
 
交割时：def on_close(self):
 
self.common_close()
 
def common_close(self):
 
print datetime.now()
 
print "Open connections are:"
 
print clients.keys()
 
print "Closing connection %d." % self.id
 
end = datetime.now()
 
timeonline = end - self.ini_time
 
timeconlastmsg = self.last_message_time - self.ini_time
 
print "Total time online:"
 
print timeonline
 
print "Time between connection start and last message received:"
 
print timeconlastmsg
 
if self.id in clients.keys():
 
del clients[self.id]
 
print "Number of open connections: %d" % len(clients)
 
print "Open connections are:"
 
print clients.keys()
 
超时：def force_close(self):
 
timout = datetime.now()
 
print timout
 
print "Connection %d timed out, server is dropping the connection." % self.id
 
self.common_close()
 
self.close()
 
超时工作，并调用函数force_close。但似乎即使在被调用并从clients中删除连接之后，该连接仍然是打开和活动的。在
 
以下是该计划的输出示例：New connection. ID: 66919
 
Total number of open connections: 3
 
2015-07-14 21:51:48.387892
 
New connection. ID: 12012
 
Total number of open connections: 4
 
2015-07-14 21:51:48.641603
 
Open connections are:
 
[66919, 12012, 11281, 97458]
 
Closing connection 66919.
 
Total time online:
 
0:00:00.404316
 
Time between connection start and last message received:
 
0:00:00
 
Number of open connections: 3
 
Open connections are:
 
[12012, 11281, 97458]
 
... ...
 
Number of open connections: 4
 
Open connections are:
 
[66246, 12012, 97458, 6069]
 
2015-07-14 22:21:47.906129
 
Connection 97458 timed out, server is dropping the connection.
 
2015-07-14 22:21:47.906167
 
Open connections are:
 
[66246, 12012, 97458, 6069]
 
Closing connection 97458.
 
Total time online:
 
0:30:00.000450
 
Time between connection start and last message received:
 
0:00:00
 
Number of open connections: 3
 
Open connections are:
 
[66246, 12012, 6069]
 
2015-07-14 22:21:48.237407
 
Connection 66919 timed out, server is dropping the connection.
 
2015-07-14 22:21:48.237444
 
Open connections are:
 
[66246, 12012, 6069]
 
Closing connection 66919.
 
Total time online:
 
0:30:00.000143
 
Time between connection start and last message received:
 
0:00:00
 
Number of open connections: 3
 
可以看出，66919被“关闭”两次，间隔30分钟。有什么想法吗？在
 
另一个连接3358在假定没有更多打开的连接时关闭(再次关闭两次，间隔30分钟)：Open connections are:
 
[7046, 16287]
 
2015-07-15 11:01:13.604125
 
New connection. ID: 3358
 
Total number of open connections: 3
 
2015-07-15 11:01:28.429574
 
Open connections are:
 
[7046, 3358, 16287]
 
Closing connection 3358.
 
Total time online:
 
0:00:14.825568
 
Time between connection start and last message received:
 
0:00:00
 
Number of open connections: 2
 
Open connections are:
 
[7046, 16287]
 
--
 
Open connections are:
 
[]
 
2015-07-15 11:31:13.629530
 
Connection 3358 timed out, server is dropping the connection.
 
2015-07-15 11:31:13.629586
 
Open connections are:
 
[]
 
Closing connection 3358.
 
Total time online:
 
0:30:00.025556
 
Time between connection start and last message received:
 
0:00:00
 
Number of open connections: 0
 
Open connections are:
 
[]
 
有人指出我不应该在force_close中调用common_close，因为on_close将被{}调用，但是{}不会被{}调用。在

 
1.什么是WebSocket
 
websocket和长轮询的区别是客户端和服务器之间是持久连接的双向通信。
 
协议使用ws://URL格式，但它在是在标准HTTP上实现的。
 
2.tornado的WebSocket模块
 
tornado在websocket模块中提供了一个WebSocketHandler类，这个类提供了和已连接的客户端通信的WebSocket事件和方法的钩子。
 
open方法，新的WebSocket连接打开时被调用。
 
on_message方法：连接收到新消息时被调用。
 
on_close方法：客户端关闭时被调用。
 
write_message方法：向客户端发送消息时被调用。
 
close方法：关闭连接时调用。
 
3.WebSocket使用示例
 
1)和http长轮询中示例一样，区别在于“主页长轮询商品当前库存”的方式。
 
classWebSocketHandler(tornado.websocket.WebSocketHandler):defopen(self):
 
self.application.shoppingCart.register(self.callback)defon_close(self):
 
self.application.shoppingCart.unregister(self.callback)defon_message(self):pass
 
defcallback(self,count):
 
self.write_message('{"inventorycount":"%s"}'%count)
 
on_close方法：在客户端关闭时被调用。
 
on_message方法：因为服务端不需要接收客户端消息，所以这里是个空函数
 
2)客户端WebSocket请求如下
 
functionrequestInventory() {var host = 'ws://localhost:9999/websocket';var websocket = newWebSocket(host);
 
websocket.onopen= function(evt) { };
 
websocket.onmessage= function(evt) {
 
$('#count').html($.parseJSON(evt.data)['inventoryCount']);
 
};
 
websocket.οnerrοr= function(evt) { };
 
}
 
3)运行结果
 
打开多个客户端，当做添加/删除操作时，可以观察到库存数量会实时变动。
 
4.WebSocket和长轮询
 
WebSocket和长轮询的不同之处在于使用了一个持久的长连接，来代替长轮询中循环发送请求连接。

1、长轮询
 
一句话来概括：长轮询就是客户端和服务器端保持连接，相互发信息。
 
2、流程
 
前端发出一个请求。
后端接收到请求后，触发on_message方法（执行write_message("hello")）。
前端收到“hello”触发on_message方法（执行渲染，把hello渲染到页面上）。
后端开始轮询，向前端发消息。
前端接收到信息后不断渲染新的内容。
 
3、代码示例
 
3.1 handler
 
利用PeriodicCallback进行轮询操作。 PeriodicCallback构造函数可以接收2个参数，一个是回调的函数，一个是间隔的时间。
 
class LastWeekTotalCarsHandler(WebSocketHandler):
    def init(self):
        self.last = time.time()
        self.stop = False

    def check_time(self):
        if time.time() - self.last > 10:
            today_total = get_last_week_total_cars(0)
            last_week_total = get_last_week_total_cars(-7)
            last_month_total = get_last_week_total_cars(-30)
            self.write_message(",".join([str(today_total), str(last_week_total), str(last_month_total)]))
            self.last = time.time()

    def open(self):
        """
        :return:
        """
        print("wedsocket opened")
        self.init()
        # PeriodicCallback构造函数可以接收2个参数，一个是回调的函数，一个是间隔的时间
        self.timer_loop = tornado.ioloop.PeriodicCallback(self.check_time,5000)
        self.timer_loop.start()

    def on_message(self, message):
        print("on message")
        today_total = get_last_week_total_cars(0)
        last_week_total = get_last_week_total_cars(-7)
        last_month_total = get_last_week_total_cars(-30)
        self.write_message(",".join([str(today_total), str(last_week_total), str(last_month_total)]))
        self.last = time.time()

    def close(self, code=None, reason=None):
        self.timer_loop.stop()
 
3.2前端
 
JavaScript：
 
<script type="text/javascript">
    var ws = new WebSocket("ws://127.0.0.1:8000/total_cars/");
    ws.onopen = function () {
        ws.send("Hello, world");
    };
    ws.onmessage = function (evt) {
        var today_total = document.getElementById("todaytotal");
        var last7total = document.getElementById("last7total");
        var last30total = document.getElementById("last30total");
        var arr = evt.data.split(",");
        today_total.innerHTML = arr[0];
        last7total.innerHTML =arr[1];
        last30total.innerHTML = arr[2];
    };
</script>
 
HTML：
 
<!-- ECharts -->
<div class="container">
    <!--    <div class="col-md-2"></div>-->
    <div class="col-md-9">
        <div id="zqhistogram" style="width: 600px;height:400px;"></div>
    </div>
    <div class="col-md-1" style="text-align: center;color: rgb(71,200,211)">
        <h5>今天总过车量</h5>
        <h2 id="todaytotal"></h2>
    </div>
    <div class="col-md-1" style="text-align: center;color: rgb(71,200,211)">
        <h5>近7天总过车量</h5>
        <h2 id="last7total"></h2>
    </div>
    <div class="col-md-1" style="text-align: center;color: rgb(71,200,211)">
        <h5>近30天总过车量</h5>
        <h2 id="last30total"></h2>
    </div>
</div>
 
4 展示
 
 
 
 
 

 
一、主题：实时展示服务器端动态生成的日志文件
 
二、流程：
 
1. 客户端浏览器与服务器建立websocket 链接，服务器挂起保存链接实例，等待新内容触发返回动作
 
2. 日志服务器脚本循环去发现新内容，发现新行向 tornado等待API POST 发送新内容
 
3. tornado 处理器接收到新内容， 通过 websocket 向保存的客户端链接返回新行
 
4. 客户端浏览器接收到新内容，修饰，展示
 
三、代码：
 
1. tornado服务器url路由、基本页面handler 及 html：
 
#模块路径根据自身项目而定
 
(r'/logs/index/', 'apps.logs.handler.IndexHandler'),
 
(r'/logs/newlinesforcallbacker/', 'apps.logs.handler.WriteNewLinesHandler'),
 
(r'/logs/newlinesforserver/', 'apps.logs.handler.ReceiveNewLinesHandler'),
 
classIndexHandler(BaseHandler):'''主页'''
 
def get(self, *args, **kwargs):
 
self.render('logs/index.html')
 
this logs monitor