A socket is an abstract network construct with a sending and receiving side. In most modern operating systems (OS) there are device representations, and programming tools to address sockets.

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86
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7answers
129k views

How to forcibly close a socket in TIME_WAIT?

I run a particular program on linux which sometimes crashes. If you open it quickly after that, it listens on socket 49201 instead of 49200 as it did the first time. netstat reveals that 49200 is in ...
11
votes
5answers
30k views

Nginx + php5-fpm = “File not found”

I've hit a wall whilst setting up a site using nginx / fpm. The page displays "File not found", and this appears in the nginx error.log: FastCGI sent in stderr: "Primary script unknown" while reading ...
12
votes
1answer
14k views

Configuring Apache 2.4 mod_proxy_wstunnel for Socket.IO 1.0

I'm trying to configure Apache 2.4 for proxying the websocket connection for socket.io to a node.js websocket server, using mod_proxy_wstunnel. We had this working fine with socket.io 0.9, but with ...
9
votes
3answers
18k views

How to automatically restart a service on failure in Linux

On Windows, you can set what should happen if/when a service fails. Is there a standard way of achieving the same thing on Linux (CentOS in particular)? A bigger part of my question is: how do you ...
25
votes
2answers
12k views

Unix socket vs TCP/IP host:port

Could someone please describe to me the pros and cons of using a Unix socket file vs a tcp/ip localhost:port when setting up services on a server (Ubuntu, FWIW)? In this particular instance it's for ...
8
votes
3answers
8k views

What are the ramifications of setting tcp_tw_recycle/reuse to 1?

I set both tcp_tw_recycle/reuse to 1 in my configuration file. What are the ramifications of doing this? If a tcp socket is re-used, does that pose a security risk? i.e. 2 different connections both ...
13
votes
2answers
10k views

Create Unix Named Socket from the Command Line

Is there a command similar to mkfifo but for domain sockets?
1
vote
1answer
7k views

Apache server : Reverse proxy and websockets via mod_proxy_wstunnel

I have a little problem with the web sockets and my reverse proxy apache, i have upgraded in latest release 2.4.5 and loaded the module mod_proxy_wstunnel. The httpd.conf : <VirtualHost *:80&...
-2
votes
3answers
514 views

understanding resolv.conf nameserver through system calls [closed]

I am trying to understand how /etc/resolv.conf /etc/nsswitch.conf exactly works and what is significance of nameserver entry 127.0.1.1 I did strace ping google.com to get to know about the system ...
28
votes
2answers
26k views

What's the difference between Unix socket and TCP/IP socket?

It's from this answer: http://stackoverflow.com/questions/2482411/is-this-pdo-bug-fixed-now/2482424#2482424
15
votes
6answers
27k views

What should mysqld.sock contain, why don't I have it?

Does anyone know why my /var/run/mysqld/mysqld.sock socket file would not be on my computer when I install (or reinstall) MySQL 5.1? Right now, when I try to start up a server with mysqld, I get ...
15
votes
4answers
18k views

Need to increase nginx throughput to an upstream unix socket — linux kernel tuning?

I am running an nginx server that acts as a proxy to an upstream unix socket, like this: upstream app_server { server unix:/tmp/app.sock fail_timeout=0; } server { listen ###.###.###....
9
votes
4answers
10k views

Max number of socket on Linux

It seems that the server is limited at ~32720 sockets... I have tried every known variable change to raise up this limit. But the server stay limited at 32720 opened socket, even if there is still 4Go ...
8
votes
1answer
5k views

Apache in linux-vserver won't start, can't create socket

During extensive research and testing to write a proper question worthy of stackexchange I found a solution: rebuild the libapr1 package inside the guest.I thought I'd nevertheless post this ...
5
votes
1answer
9k views

Keep-alive options not working on Linux for an outgoing connection

Does anyone know if Linux supports keep-alive socket options on an outgoing connection? I made an outgoing connection with keep-alive options but netstat --timers shows off (I'm assuming timers are ...
2
votes
2answers
10k views

What is the maximum number of socket connections on Linux?

How do I know the maximum number of connections allowed to my Ubuntu server?
1
vote
1answer
4k views

How to debug troubles with unix domain sockets?

Ubuntu Server 10.04.2 $ uname -a Linux my.local 2.6.32-30-generic-pae #59-Ubuntu SMP Tue Mar 1 23:01:33 UTC 2011 i686 GNU/Linux It seems that my domain socket queue is overflowing, but I can't ...
0
votes
2answers
554 views

Bandwidth Monitor

I am creating a bandwidth quota program in PHP, however I am finding that to create it with PHP is a bit hard. As an example of what I am trying to do, the user can download 10GB per day, and after ...
3
votes
1answer
2k views

High # of sockets in TIME-WAIT state, server unresponsive at load

Our app became unresponsive at high loads, with longer wait times. Process usage was abnormally low (~15% CPU utilisation per process, our app runs on 8 processes). Nginx error log output showed a ...
3
votes
2answers
2k views

How to get a service to listen on port 80 on Windows Server 2003

I've coded a custom windows service that listens on TCP port 80 but when I try to install it on a Windows Server 2003 machine it fails to start because some other service is already listening on that ...
2
votes
2answers
950 views

SELinux prevents Apache from writing to pgbouncer's Unix domain socket

I'm using freshly installed CentOS 5.7 Linux 64 bit with PGDG packages: # rpm -qa|grep -i PG postgresql-libs-8.4.8-2PGDG.rhel5 pgdg-centos-8.4-2 postgresql-8.4.8-2PGDG.rhel5 pgbouncer-1.3.4-1.rhel5 ...
2
votes
1answer
761 views

Why is there a socket interface on the host and a character device interface on the guest for virtio-serial?

I am trying to establish a communication channel between the host and one of its guest virtual machine using kvm as a hypervisor. For this, I am using virtio-serial. To create the virtual machine, I ...
1
vote
1answer
3k views

Access to a network server without port forwarding

I have a network with the following structure. The server in PC2 is simple socket server TCP in 8080 port. I need to access to PC2 from other external network by socket client. This socket client ...
0
votes
2answers
681 views

mysql error 2002 “cannot connect to socket”

I am having trouble with the server I'm running my trac on. I accidentally had the nightly back up going to the internal hard drive instead of the external. So it filled up, I erased the new files, ...
0
votes
0answers
59 views

What happens when connecting to port in TIME_WAIT state?

I'm trying to understand the effect of TIME_WAIT on subsequent TCP connections. I understand how TIME_WAIT behaves when net.ipv4.tcp_tw_reuse = 1, as explained by this answer. But what happens when ...