backlog

In case of a Serversocket have full of request in its backlog and doing a long running job what will be the socket behaviour. When I try this, from windows telnet is ok, it connects. But from unix it gets "connection refused" . My application is written in java and running on IBM jvm . By the way I came to that point where our application was not responding telnet from unix. Not respoing means it was writing "tyring..." and hangs, not refusing or connecting. Can anybody justify this behavior? Thank you. You should not get "Connection refused", if the socket is in LISTEN state. Until you

I am using MS Team Foundation Server to implemet Scrum and I would like to see the whole progress and add some columns in the board to be more clear and bright When I go to the public board of all PBIs, I can customize the delivery operation. I can Add new columns: Committed, Tested, Published etc. Public Board PBIs Picture But the problem is when I try to customize the sprint board, it seems to be untouchable I couldn’t add any new columns any way, or even edit columns name Sprint Board PBIs Picture Am I wrong trying to do such thing ? should I just leave it and live with that? Is there any

I read the man 2 listen . I don't understand what is the backlog value, it says The backlog argument defines the maximum length to which the queue of pending connections for sockfd may grow Right, how can I define what is the best value? Thanks Basically, what the listen() backlog affects is how many incoming connections can queue up if your application isn't accept() ing connections as soon as they come in. It's not particularly important to most applications. The maximum value used by most systems is 128, and passing that is generally safe. It's a fight between clients trying to connect.

How TCP backlog works in Linux January 1, 2014 (updated March 14, 2015) When an application puts a socket into LISTEN state using the listen syscall, it needs to specify a backlog for that socket. The backlog is usually described as the limit for the queue of incoming connections. 当应用程序通过 listen 系统调用令一个 socket 进入 LISTEN 状态时，需要为该 socket 指定 backlog 参数； backlog 参数通常被描述为用于保存 incoming 连接的 queue 的长度； Because of the 3-way handshake used by TCP, an incoming connection goes through an intermediate state SYN RECEIVED before it reaches the ESTABLISHED state and can be returned by the accept syscall to

As I understand, backlog determines the size of the connection queue . Any extra requests greater this size at that time will be dropped off( is this statment right?? ). Now I have very simple program server.c socket() bind() listen(..., 5) while(1) { accept() read() write() sleep(3) close() } Now, I start 8 clients at a time to connect to this server. Surprisingly, the server serves all the 8 clients but instead it should queue only 5 clients & remaining 3 clients requests should be refused. Another interesting point is even if I put this backlog value as 0, the result is still same. Then I

在之前的一篇工作日志《 【原创】记录几个最近遇到的未解问题（resolved） 》中，记录了 3 个问题，其中两个比较直接，三言两语就能够打发了，而针对最后一个问题，却有不少内容可以说说，本文针对“ 终端设备通过 HTTP 协议经由 nginx 访问后端的 api 服务器时，TCP 连接行为诡异 ”这个问题展开讨论。 问题描述 ： 线上环境中，公司自研即时通讯软件不定时掉线。 问题排查 ： 由运维和测试人员发现并报告，线上环境出现网络异常，具体表现为登录服务器虚拟 IP 地址无法 ping 通，即时通讯工具不定时掉线； 在此情况下，现场人员第一反应就是受到了外部攻击（因为以前遇到过攻击情况），因为看到了如下信息 ... Apr 20 18:21:48 localhost kernel: possible SYN flooding on port 80. Sending cookies. Apr 20 18:24:37 localhost kernel: possible SYN flooding on port 80. Sending cookies. Apr 20 18:25:50 localhost kernel: possible SYN flooding on port 80. Sending cookies. Apr 20 18:27:02 localhost