Apache JServ Protocol (AJP) - Introduction

AJP is a binary format protocol. In the case of HTTP which is a plain text format protocol so it creates a overhead traffic of over the network. But in AJP converts these messages into a binary code, reducing the amount of space taken by each message which results better traffic than HTTP. Mainly AJP Protocol is used for a server - server communication. Speed between collaborating servers is a distinctive feature of this protocol. The process maintains permanent connections between servers to reduce the time taken to establish contact. The main use of AJP is it can proxy inbound requests from a web server through to an application server that sits behind the web server.

In web environment AJP have great demand in load balancing. Here when one or more front end web servers (Apache HTTPD server) feeds the request into one or more Application servers (JBOSS). The sessions are redirected into the correct application server using a routing machanism where each application server gets a name which called a route . In this scenario the web server functions as a reverse proxy for the application server. If you want more then please redirect to the following url

Use of AJP Protocol

AJP is particularly used for "Load Balancing." This is where one server distributes incoming traffic among several application servers, sharing the load equally.

AJP and HTTP

The http protocol is quite expensive in terms of band width - it's an ascii text protocl with words like "POST" and phrases like "Content-type:" taking up more bandwidth than is really needed, and having to be interpreted at destination too. So the ajp protocol (Apache Java Protocol) was established to allow for much less expensive exchanges between upstream and downstream servers that are to be closely linked. ajp carries the same information as http but in a binary format. The request method - GET or POST - is reduced to a single byte, and each of the additional headers are reduced to 2 bytes - typically, that's about a fifth of the size of the http packet.