Apache JServ Protocol
From Wikipedia, the free encyclopedia
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 2.2 using the provided Proxy AJP, mod_proxy
and proxy balancer modules together. The Apache server is written in C and the application-server end is generally written in
Both the Apache Tomcat servlet container as well as the Jetty servlet container support AJP. The WebObjects application
server can run (without a servlet deployment) using the LEWOAJPAdaptor from LEWOStuff .
This protocol was originally created by Alexei Kosut in July 1997.  He also created the first implementations of it in the
same month with the releases of the Apache JServ Servlet Engine 0.9 and the Apache mod_jserv 0.9a (released on July 30,
An attempt was made at revamping the protocol to a second version in 1998 but seemingly it remains with just minor
updates at version 1.3.
1. ^ Kosut, Alexei. "Apache JServ Protocol", Version 1.0. Java Apache Project. July 1997.
2. ^ a b Apache JServ Protocol Version 2.1 (AJPv2.1) - June 30, 1998 - Draft
3. ^ Apache mod_jserv - History of Changes
The Apache Tomcat Connector - AJP Protocol Reference AJPv13
Apache JServ Protocol version 1.3 Dan Milstein, December 2000.
Apache Tomcat Configuration Reference The AJP Connector
Apache Module mod_proxy (Apache Version 2.2)
Apache Module mod_proxy_ajp
Implementation of Apache JServ protocol for Internet Information Server
The Java Apache
V · T· E· Web server interfaces
Protocols CGI · SCGI · FCGI · AJP ·
Lua WSAPI ·
Apache modules mod_jk · mod_lisp · mod_parrot · mod_perl · mod_php · mod_python · mod_wsgi · mod_ruby ·
via Apache JServ Protocol