[lvs-users] ldirectord email features

[Graeme Fowler]

On Thu, 2009-11-05 at 04:43 -0800, Robinson, Eric wrote:
> I'm a fan of ldirectord so I am proposing a possible feature. ldirectord
> sends me an email alert when services go down, which sometimes works too
> well. A few months ago I was replacing some switches and make a spanning
> tree mistake which caused ldirectord to be unable to reach any of my
> realservers. It took me a while to find the problem, during which I made
> several changes to the network infrastructure. As a result, I got about
> 2500 text messages on my cell phone from ldirectord. More recently, I
> enabled a script that restarts certain services every night, so now I
> get 250 text messages on my cell every night!

Disregarding for a moment the time-based stuff (and exceptions to that),
what you're asking for is an implementation of "flap detection", in
essence - if event A happens more often than frequency X, suppress
notifications.

More widely - if ldirectord notices a service/host is flapping, should
it remove that host/service and lengthen the check time before testing
again? It could have a geometric growth, too.

Not sure I could code that right now but it's fairly widely applied
logic in networking monitoring.

Graeme