Since our server runs several web apps for internal, partner and external use, I was looking for something to monitor it automatically. Last year I tried a couple of monitoring services from the US, where their PC pings our server or grabs a web page. Both of them completely failed to deliver -- on one the automated system to try out their service for free didn't respond at all, and on the other it responded, but then only ever pinged our server once.

Whilst an external service would be best, having one directly on our server is still useful. If just one service on the server fails, emailing or paging me will generally work fine. With a little ingenuity, it's also possible to check network connectivity, e.g. if our server checks a web page elsewhere, which loads a page from our server.

For the moment, we're going with PA Server Monitor, which seems to be working quite nicely. It has an impressive array of things it can check, all highly configurable, but with a nice default set of choices. No "customization cliff" here, and yet no need to hand-code things :-). There are versions ranging from free to $99 per server, and even the free ones do a useful job.

Their WatchDisk software also seems like a good idea, if you too have users who sometimes hog too much server disk space, but you don't fancy going all totalitarian and imposing quotas.

If you know of any other good solutions, do share them with others by posting a comment!