The Apache JServ Protocol (AJP) is a binary protocol that can proxy inbound requests from a web server through to an application server

that sits behind the web server.

It also supports some monitoring in that the web server can ping the application server. Web implementors typically use AJP in a

load-balanced deployment where one or more front-end web servers feed requests into one or more application servers. Sessions

are redirected to the correct application server using a routing mechanism wherein each application server instance gets a name (

called a route). In this scenario the web server functions as a reverse proxy for the application server.

AJP runs in Apache HTTP Server 1.x using the mod_jk plugin and in Apache 2.x using the provided Proxy AJP, mod_proxy and proxy

balancer modules together. Implementations exist for the lighttpd 1.5, nginx, Grizzly 2.1, and the Internet Information Server.

Both the Apache Tomcat servlet container as well as the Jetty servlet container support AJP.

Apache JServ Protocol (AJP)