Reverse Proxy with Multiple Backend Web Servers
Warning: Any example presented here is provided "as-is" with no support or guarantee of suitability. If you have any further questions about these examples please email the squid-users mailing list.
Sending different requests to different backend web servers
For example the websites are hosted like this on two servers:
- www.example.com hosted on server1
- example.com hosted on server1
- download.example.com hosted on server2
- *.example.net hosted on server2
- example.net hosted on server2
Switching on Domains
cache_peer ip.of.server1 parent 80 0 no-query originserver name=server_1 acl sites_server_1 dstdomain www.example.com example.com cache_peer_access server_1 allow sites_server_1 cache_peer ip.of.server2 parent 80 0 no-query originserver name=server_2 acl sites_server_2 dstdomain www.example.net download.example.com .example.net cache_peer_access server_2 allow sites_server_2
cache_peer ip.of.server1 parent 80 0 no-query originserver name=server_1 cache_peer_domain server_1 www.example.com example.com cache_peer ip.of.server2 parent 80 0 no-query originserver name=server_2 cache_peer_domain server_2 download.example.com .example.net
This directive has been removed in Squid-4.
Other Criteria than Domain
It is also possible to route requests based on other criteria than the host name by using other acl types, such as urlpath_regex.
For our example here the websites /foo directory alone is hosted on a second server:
- example.com is hosted on server1
- example.com/foo is hosted on server2
acl foo urlpath_regex ^/foo cache_peer ip.of.server1 parent 80 0 no-query originserver name=server1 cache_peer_access server1 deny foo cache_peer ip.of.server2 parent 80 0 no-query originserver name=server2 cache_peer_access server2 allow foo cache_peer_access server2 deny all
Remember that the cache is on the requested URL and not which peer the request is forwarded to so don't use user dependent acls if the content is cached.