How to get a more stable socket connection in Linux/C.

Question

I'm running a game website where users connect using an Adobe Flash client to a C server running on a Fedora Linux box.

Often users complain about disconnects. Usually they're "Connection reset by peer"-disconnects.

Is there any way to make the connection more stable or does it all depend on the route from the user host to my server?

One thing I tried is to make it more stable by sending PING in clear text every other minute to avoid timeout problems.

Anyone got more ideas?

Answer 1

where are you running the server?
at home? at work? at a hosting facility?
this will make a very big difference.

Can you design your app to connect to two sockets on the server and then load balance or make it active/passive (or active/active)?

Answer 2

You can use SO_KEEPALIVE TCP socket option.

Answer 3

You are not exhausting the number of socket/memory use/cpu that the server process is given on the server, are you?

Do check with ulimit.

Also, if possible try to trace the error message in the source code (when a RST packet is sent--), i.e. when a send() or accept() returns an error value. In such cases print a debug message into the logs; if you really fancy debugging it do a simulation of the server:

• run it into debug mode on a separate machine (possibly a clone of the server)
• simulate thousands of connection (or find a network harnessing program)
• backtrace the call and/or sniff the connection