Load balancing / Load Balancing Configuration Examples |
Internet Information Services (IIS) 5.x and 6.0 have no built-in tools to do load balancing. However, third party tools do exist.
One third-party tool is ISAPI_Rewrite, which aims to enable Apache mod_rewrite on IIS.
# Helicon ISAPI_Rewrite configuration file # Version 3.1.0.66 RewriteEngine on RewriteMap servers rnd:hosts.txt RewriteRule ^/(.*) http://${servers:host}/$1 [P,L]
host GAS1.corporate.com|GAS2.corporate.com
For example, the http://localhost/ws/r/echo URL will be rewritten to http://GAS1.corporate.com/ws/r/echo, assuming that the GAS1.corporate.com server has been chosen.
# Helicon ISAPI_Rewrite configuration file # Version 3.1.0.66 RewriteEngine on RewriteMap servers rnd:vdirs.txt RewriteRule ^/gas/(.*) /${servers:vdir}/$1 RewriteRule ^/GAS1/(.*) http://GAS1.corporate.com/GAS1/$1 [P,L] RewriteRule ^/GAS2/(.*) http://GAS2.corporate.com/GAS2/$1 [P,L]
vdir GAS1|GAS2
For example, the http://localhost/gas/wa/r/gwc-demo URL will be rewritten to http://localhost/GAS2/wa/r/gwc-demo, assuming that the servers:vdir variable contains GAS2 at this time, then will be rewritten to http://GAS2.corporate.com/GAS2/wa/r/gwc-demo. Likewise, the http://localhost/GAS2/wa/sua/93837374/1 URL will be rewritten to http://GAS2.corporate.com/GAS2/wa/sua/93837374/1.