HTTP 1.0

From LB Wiki

HTTP 1.0 is the first iteration of the HTTP protocol in use since 1990. Browsers and servers are capable of speaking HTTP 1.0, although HTTP 1.1 is far more common. As far as load balancing is concerned, HTTP 1.0 has one major difference from HTTP 1.1, and that's how it handles TCP connections.

With HTTP 1.0, each request (POST, GET, etc.) is followed by a closed TCP connection. If you're pulling a page with 20 images, this would require 21 (images plus the HTML) individual TCP connections. This is tough on the web server, and it's tough on a load balancer.

HTTP 1.1 fixed this with the ability to use a persistent connection (not to be confused with persistence in the load balancing sense), which opens one TCP connection for multiple requests. So pulling a page with 20 images requires only one TCP connection.

Since load balancers, like servers, are typically connection rate constrained, using HTTP 1.1 on your server is important.

Load Balancers and HTTP 1.0/1.1

By default, modern browsers, web servers, and load balancers will default to HTTP 1.1. There are some situations where running HTTP 1.0 is required, and it can be configured on the web server. Some load balancers support forcing client requests to HTTP 1.0, while others do not.

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