mtcp

mtcp module for disperse your network transfer over multi sockets, thus improve network speed if you get per-connection speed limit. Otherwise you will too soon comsume too many connections and can not connect any more.

mtcp module was originally forked from wsmlby/mtcp, with several patches to make it easier to use and stable.

usage

---

mtcp will forward a remote port on a server to a local port on your machine via multi sockets:

Applications <--> local:local_port <-- multi sockets --> host:host_port <--> host:remote_port

Now you can use local_port on your machine as using remote_port on a server.

For example, you can open a ssh tunnel on you server (ssh to localhost), then use mtcp to forward it to your local machine, and now get a socks5 proxy at localhost:local_port.

setup

configuration

This module is still under development. You must provide a config.json at mtcp directory:

{
    "host":"you_host",
    "host_port":"host_port",
    "remote_port":"remote_port",
    "local_port":"local_port",
    "somaxconn":10
}

host has been tested against IPv6 only. host_port is used by mtcp itself.

Right now mtcp will create somaxconn sockets for a single connections. So you would like to increase your max files open limit and max tcp connection limit on both server and client.

increase max connection limit

Linux

edit /etc/security/limits.conf and add lines like

username	soft	nofile	65535
username	hard	nofile	65535

To change limits for any user(except root), you could replace username with *, but you must specify root for changing limits for root user.

You may also want to add something like ulimit -n 10240 to your /etc/profile

change max cocurrent connection

use sudo sysctl -w net.core.somaxconn=65535

OS X

increate max open files

$ sysctl -a | grep files
kern.maxfiles = 12288
kern.maxfilesperproc = 10240

kern.maxfiles and kern.maxfilesperproc were small numbers, they need to be increased:

$ sudo sysctl -w kern.maxfiles=12288
$ sudo sysctl -w kern.maxfilesperproc=10240

after this, you can increase your account’s limit by ulimit -n:

$ ulimit -n 10240

increate max sockets

$ sysctl -a | grep somax
kern.ipc.somaxconn: 2048

and

$ sudo sysctl -w kern.ipc.somaxconn=2048

You may also want to add something like ulimit -n 10240 to your /etc/profile

Windows

you may open a wrong url by accident

Port Forwarding

use

node local.js

on client (the host you can access)

and

node server.js

on server (the other end).

Known issues

This module is not stable yet.

Right now mtcp has some bugs causing memory leaks. If you can help, feel free to send pull requests.

mtcp will release unused sockets for a timeout. So it may hold many sockets at the same time (maybe thousands). It will release them after a period of time. I hope this could be fixed soon.

mtcp disperse data and re-assemble then on remote server. So it would comsume much CPU time if you set a big value for somaxconn, and won't increase speed any more.

Warnning

Don't abuse this package to get much more bandwidth than yourself need like massive downloading or provide service to others.

License

(MIT)