Hi, On Fri, Jan 08, 2010 at 12:51:46AM +1100, Aristedes Maniatis wrote: > I'm working on a web UI for administering the haproxy config and I have a > question I can't find the answer to in the documentation. Are the listener > blocks unique with respect to IP:port? That is, is this valid: > > > listen > bind 1.2.3.4:80 > acl someAcl... > server 1.2.5.1 ifsomeAcl > > listen > bind 1.2.3.4:80 > acl someOtherAcl... > server 1.2.5.1 if someOtherAcl > > Are these listeners like a Unix listener, only one unique IP:port pair is > allowed. Or are duplicates OK and they are executed in order from the top > to the bottom under a backend server is matched?
This depends on the OS in fact. Haproxy accepts such a configuration, but on most OSes it will not be able to bind the port for the second instance because the OS will refuse to bind it a second time. Some variants or patched ones will accept it though. In practice, the example above is really useless because you can't know what listener will get the request, the OS will randomly distribute it to any socket. However, it is very useful when you bind to an interface : listen bind 1.2.3.4:80 interface eth0 acl someAcl... server 1.2.5.1 ifsomeAcl listen bind 1.2.3.4:80 interface eth1 acl someOtherAcl... server 1.2.5.1 if someOtherAcl This time there is no ambiguity and the OS will allow it (assuming it supports per-interface binding). Regards, Willy
