nginx-upstream-jvm-route

http://code.google.com/p/nginx-upstream-jvm-route/

nginx_upstream_jvm_route

---

This module achieves session stickiness with the session cookie. If the session is not in the cookie or URL, the module will be a normal Round-Robin upstream module.

INSTALLATION

    cd nginx
-
0.7
.
59
 
# or whatever

    patch 
-
p0 
<
 
/path/
to
/
this
/
directory
/
jvm_route
.
patch

compile nginx with the following addition option:

    
--
add
-
module
=
/path/
to
/
this
/
directory

EXAMPLE

1.For resin

upstream backend 
{

    server 
192.168
.
0.100
 srun_id
=
a
;

    server 
192.168
.
0.101
 srun_id
=
b
;

    server 
192.168
.
0.102
 srun_id
=
c
;

    server 
192.168
.
0.103
 srun_id
=
d
;


    jvm_route $cookie_JSESSIONID
;


}

detail

2.For tomcat

upstream backend 
{

    server 
192.168
.
0.100
 srun_id
=
a
;

    server 
192.168
.
0.101
 srun_id
=
b
;

    server 
192.168
.
0.102
 srun_id
=
c
;

    server 
192.168
.
0.103
 srun_id
=
d
;


    jvm_route $cookie_JSESSIONID reverse
;


}

detail

3. A simple jave test page

here

DIRECTIVES

jvm_route

syntax: jvm_route $cookie_COOKIE[ |session_url] [ reverse]

default: none

context: upstream

description:

'$cookie_SESSION_COOKIE' specifies the session cookie name(0.7.24+). 'session_url' specifies a different session name in the URL when the client does not accept a cookie. The session name is case-insensitive. In this module, if it does not find the session_url, it will use the session cookie name instead. So if the session name in cookie is the name with its in URL, you don't need give the session_url name.

With scanning this cookie, the module will send the request to right backend server. As far as I know, the resin's srun_id name is in the head of cookie. For example, requests with cookie value 'a* * * ' are always sent to the server with the srun_id of 'a'. But tomcat's JSESSIONID is opposite, which is like '* * * .a'. The parameter of 'reverse' specifies the cookie scanned from tail to head.

If the request fails to be sent to the chosen backend server, It will try another server with the Round-Robin mode until all the upstream servers tried. The directive proxy_next_upstream can specify in what cases the request will be transmitted to the next server. If you want to force the session sticky, you can set 'proxy_next_upstream off'.

server

Every syntax is the same with the official directive except the parameter of 'srun_id' which identified the backend JVM's name by cookie. The default srun_id's value is 'a';

NOTE

This is a third-party module. And you need careful test before using this module in your production environment.

Questions/patches may be directed to Weibin Yao, [e-mail].