On 2006/10/20 17:19, Alexander Lind wrote: > For example, if I have PF round-robin to 4 webservers, and one goes > down, is there any way to make PF notice this and remove the downed > host from the pool, based on something as simple as missing ping > replies?
carp is good for this. run it on the backends, and load-balance to protected addresses. even if you have other mechanisms to take failed servers out the pool (which you may want e.g. in case httpd is dead but the box is alive) this is a useful backup mechanism. > Even cooler if it could interface with some SNMP service, like nagios. > > If not supported natively, does anyone know of any other software I > could use to achieve something like this? monit (in ports) has a reasonable range of checks and is designed so that it can take corrective action itself - as well as a bunch of on-host checks (checks processes, file changes, cpu%) it can check other machines too, check host ... if failed url ... then exec ... main thing I don't like is it's a bit over-fond of pid files, but that doesn't affect checking other hosts obviously. nagios has a better range of options for bothering you so they're somewhat complementary.
