Apache jserv Protocol (AJP)

The Apache jserv Protocol (AJP) is a binary Protocol this can proxy inbound requests from a Web server through to an appli cation 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 feeds requests into one or more application servers. Sessions

is 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 P Roxy

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 servlets container support AJP.

AJP is a directional packet protocol. For performance reasons, use binary format to transfer readability text. The Web server is connected through a TCP connection and a servlet container. To reduce the cost of the process to generate a socket, the Web server and the servlet container try to maintain a persistent TCP connection and reuse a connection for multiple request/reply loops. Once the connection is assigned to a specific request, it is not allocated before the request processing loop ends. In other words, on the connection, the request is not plural. This is the connection at both ends of the coding made easy, although this leads to a lot of connections at a time. Once a Web server opens a connection to a servlet container, the connection is either idle or dispatched once a connection is assigned to a specific request, the basic request information sent on the connection is highly compressed. At this point, the servlet container is probably ready to start processing the request, and when it is processed, it can send back the following information to the Web server: (1) Send_headers, (2)Send_body_chunk, (3)Get_body_chunk, (4)Design of End_response AJP protocol http://httpd.apache.org/docs/2.2/mod/mod_proxy_ajp.html

Apache jserv Protocol (AJP)