On Wednesday, December 13, 2006, at 17:14:39, Karl O. Pinc wrote: > On 12/13/2006 09:40:03 AM, Sylwester S. Biernacki wrote: >> On Wednesday, December 13, 2006, at 15:59:02, Karl O. Pinc wrote: >> >> > OpenBSD has ifstated, which is pretty simple to configure >> > state engine. >> >> it's true, but it's unusable here - if machine get 100% cpu load it >> won't put down their interface.
> ifstatd will run scripts. ifstated(8) ? ifstatd is on FreeBSD :P > You'd have to > write various scripts on the load balancer > to monitor various aspects of the webservers. > And various scripts to fiddle with the load balancing > as a result. The only thing ifstatd would do "automatically" > is detect if one of the load balancer's interfaces went down > for whatever reason. That _is_ something that > you'd want to do to be through. ok, i agree, it can be useful, however the main problem is not to check if load-balancer interface is down, but if webservers are working and replying to i.e. HTTP or not. Load balancing in PF is just packet redirection what makes it without a big impact on CPU or kernel. And it makes load-balancer much more reliable than webservers. Anyway, if you have two CARP load-balancers and wish to make checking only once (by current MASTER) it is good to use it :) > You could use > snmp or roll your own for whatever > monitoring plugin scripts you'd need. All > ifstatd provides is a basic control > framework. This is an advantage because the state engine > approach makes things nice and modular. ok, if it's nice or not I won't tell - I know nicer progs :P > The only limitation is that ifstatd uses polling > for everything but the interface detection. There are no perfect progs (even if m$ are telling that :P)... But imho it may not be limitation for other purposes of ifstated :) -- Sylwester S. Biernacki <[EMAIL PROTECTED]> X-NET, http://www.xnet.com.pl/
