comet

Maximum server file access frequency

由 别等时光非礼了梦想. 提交于 2019-12-25 04:39:08
问题 I'm trying to create a AJAX push implementation in PHP using a Comet long-polling method. My code involves using file_get_contents() to read a file repeatedly to check for any messages to send to the user. To reduce server load, I'm using two text files; one containing the actual command and one acting as a "change notifier", which either is iterated through 0-9 or contains a UNIX timestamp. My question is, how often can I access and read from a small (only a few bytes) file without

How do i refresh the session in comet?

由 一个人想着一个人 提交于 2019-12-25 04:22:40
问题 I want to have a comet-like iframe on my page, but when the session changes the info in the iframe does not and i did a dump of the $_SESSION variable in the iframe and it was not changing. My question is, how do i update the $_SESSION variable in the comet iframe when the client $_SESSION changes? Thanks so much ^_^ update with code: client: <?php session_start(); if(!isset($_SESSION['count'])) $_SESSION['count'] = 0; ?> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html>

Binding to global variables in Polymer

由 ￣綄美尐妖づ 提交于 2019-12-24 15:25:26
问题 I am fairly new to Polymer, and only just studied how data binding works. I am porting an existing Dojo application, where there would be: 1) A single store (holding data) for each URL 2) A message from the server when a store element was updated As a result, a dynamically made select box which depended on data in the store would automagically have an extra item if anywhere in the application a user added an item to the store (which held the data) I am trying to replicate something like this

What technology does GCM (Google Cloud Messaging) use?

由 Deadly 提交于 2019-12-24 04:23:05
问题 Does it work by polling the servers periodically ? Does it work using long-held http request , like comet ? Or theres some new technology they are using ? 回答1: Here is a good overview: http://developer.android.com/google/gcm/gcm.html Somewhere it explains that GCM is preferred to the app polling because the Android OS is doing the polling through a long-held OS connection to the GCM server. So even though they call it "push" technology it is really being polled/pulled by the device. The OS

PHP comet usleep blocking apache mpm?

由 ﹥＞﹥吖頭↗ 提交于 2019-12-24 03:27:52
问题 I've a comet there I run an while loop in this way $items = $statement->fetchAll();//statement is a PDO Statement $iteration = 0; while(count($items) == 0 && $iteration < 100){ $items = $statement->fetchAll(); usleep(10000); ++$iteration; } When the comet runs I can see all other HTTP requests are pending. even non-database requests are pending. Why ? 回答1: You need to manually commit using PDO::commit as the request are being hold in a transaction. Please see the docs about this behavior:

When will a framework be available for Comet?

由 為{幸葍}努か 提交于 2019-12-24 03:01:47
问题 I wonder why it's so difficult to set up a server for live notifications with Comet. Will this ever be implemented in existing frameworks like Rails? It's popularity is huge, but it's still not easy to get it up and running. What options are there for Rails applications today? Thanks 回答1: What about http://pusherapp.com ? 回答2: A single script can be used to get live updates using WebSync On-Demand 来源： https://stackoverflow.com/questions/3375318/when-will-a-framework-be-available-for-comet

Comet vs Ajax for chatting

由 痴心易碎 提交于 2019-12-24 00:41:54
问题 My site needs a chat room, and I'm also looking to implement a facebookesque person to person chat system. What is most cost-efficient/performant (purely in terms of bw and server) for me. A regular 1 second poll ajax chat, or a comet solution. Thanks. 回答1: Comet would typically result in lower bandwidth usage (assuming less than 1 chat message per second per chat on average), owing to the fact that it will only query the server once per message sent. It would typically result in more

What is the magic behind Lightstreamer?

由 江枫思渺然 提交于 2019-12-23 09:11:04
问题 I'm gonna develop a framework for comet programming, and I can't use Web Sockets, or Server-Sent Events (because browser support really sucks). So, I need to keep the HTTP connection alive, and send chunked data back to the client. However, problems show themselves as you get into the work: Using XMLHttpRequest is not possible, due to the fact that IE doesn't give you xhr.responseText while the xhr.readyState is 3. A hidden iframe can't be useful, because browser shows the loader while I send

AJAX Server Push

由 拜拜、爱过 提交于 2019-12-23 04:34:14
问题 Well, I have doubts about this technology, more precisely in its implementation, can not find good examples on the Internet, as it involves javascript and php, only, you would have some links where I can find this stuff really works and that ? 回答1: A great source for all things Comet is Comet Daily. Unfortunately it's not updated all that often any more but there are some fantastic old articles in there. It's contributed to by guys that have been developing Comet solutions for over 10 years.

基于dwr2.0的Push推送技术详细解析以及实例

由 ￡可爱￡侵袭症＋ 提交于 2019-12-22 14:29:55
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> DWR从2.0开始增加了push功能,也就是在异步传输的情况下可以从Web-Server端发送数据到 Browser. 我们知道,Web的访问机制天生是设计用来pull数据的,也就是只允许Browser端主动发起请求,server 是被动的响应.不允许Server向Browser发出一个connection请求,也就是说没有为server向Browser push数据提供设计实现. 虽然没有直接的实现方法,却可以使用一些变通的方式完成类似的功能: 1. Polling Polling其实就是轮询,是通过Browser在一个相对短的间隔时间内,反复向Server发出请求,然 后更新页面,这种方式没有什么新鲜的,只是需要浏览器端做一些工作就可以,哪怕没有太多服务器端的配 置也没问题.轮询的方式对于服务器来说会依据不同的访问间隔而产生不同程度的额外负载,因为每次访 问都有重新建立连接的过程. 2. Comet Comet方式通俗的说就是一种长连接机制(long lived http).同样是由Browser端主动发起请 求,但是Server端以一种似乎非常慢的响应方式给出回答,这样在这个期间内,服务器端可以使用同一个 connection把要更新的数据主动发送给Browser.Comet又有很多中实现方式
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