Question

I am working on an ajax long polling type application, and I would like to minimize the amount of bandwidth I am using. One of the big costs right now are the client side HTTP headers. Once I have a connection established and a session id stored on the client, I don’t really want to squander any more bandwidth transferring redundant http information (such as browser type, accept encodings, etc.). Over the course of many connections, this quickly adds up to a lot of data!

I would really like to just take my XMLHttpRequest and nuke all of the headers so that only the absolute minimum gets transmitted to the server. Is it possible to do this?

Answer 1

You have very little control over request headers, but you can still do a few things –

1. Reduce the size of the cookie. In general, you only want the session id, everything else can be eliminated and stored server side.
2. Minimize http referrer by keeping a short URL. The longer your page url, the more data will have to be sent via the http referrer. One trick is to store data in the fragment identifier (the portion of the url after the #). The fragment identifier is never sent to the server, so you save a few bytes over there.
3. Some request headers are only sent if you had previous set corresponding response headers. For example, you can indirectly control the ETag and if-modified-since request headers.

You may want to consider Web Sockets. Support is pretty good (IE10+).