srijanmukherjee/load-balancer-c

load balancer demo using c

Load Balancer in C

A very basic implementation of a round robin load balancer using C. It redirects request to predefined list of servers using the round robin policy.

This is for demonstration and learning purpose only, and thus used fork() to quickly handle multiple clients instead of using proper techniques like polling.

From the demonstration we learned that the proxy <-> remote and client <-> proxy sockets do not close by themselves automatically by default. There are a lot of possiblities depending on the different header values. For example, the Keep-Alive header is set to timeout=5, which kept the server socket open for 5secs. If a request went in between those 5sec, the timeout is reset and the same pair of remote <-> proxy and client <-> proxy sockets are used because the remote <-> proxy socket doesn't close for 5 seconds, which in turn kept the client <-> proxy socket open.

I haven't tested this with SSL connection yet, which would be interesting to test and implement. This could potentially work if each server indivually handled SSL. But I am thinking of handling the SSL until the proxy server and then forward the decoded http request to the other servers. Kindof like nginx.

I would also like to assign a custom server name in the Server header field. I will need handle http headers in C which seems like a big challenge in itself. I may revisit this later in the future, maybe, in a higher level language.