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Hy everybody,
I'm configuring Apache as a reverse proxy and I
am doing loadbalancing between some backend servers.
I' am doing load balancing using mod_rewrite. My
backend webapps (every webapp is replicated in various servers) use cookies to
mantain sessions.
So my goal was to redirect every user to same
server he first was redirected to.
I achieved this setting the environment variable
SERVER to the server name the user is first redirected to, then storing this
value in a cookie; all the following request of the same user are then
redirected to the server whose name is stored in the "backend_server"
cookie.
My question is:
what is the scope of the SERVER environment
variable ? What happens if many users request simultaneusly ? Does the value of
SERVER is shared inconsistently ?
I mean...may a user be redirected to the wrong
server ?
Below I enclose the my config.
Any help is really appreciated.
Thanks
Andrea
RewriteMap lb
rnd:/usr/local/apache2/conf/backend.table
RewriteCond %{HTTP_COOKIE}
(^|(.+;)*)backend_server=(.+)(;?)
RewriteRule ^/s1_webconsole/(.*)$ http://%3/webconsole/$1 [E=SERVER:%3,P,L] RewriteCond %{HTTP_COOKIE}
!(^|(.+;)*)backend_server=(.+)(;?)
RewriteRule ^/s1_webconsole/(.*)$ to://${lb:www}/$1 RewriteRule ^to://([^/]+)/(.*)$ http://$1/$2 [E=SERVER:$1,P,L]
<Location /s1_webconsole>
... Header add Set-Cookie
backend_server=%{SERVER}e;Path=/s1_webconsole
... </Location> |
