This kind of server monitoring is exactly why we wrote and released <a href="http://www.nerdkits.com/files/notifo/" rel="nofollow">http://www.nerdkits.com/files/notifo/</a> two months ago (although our server monitoring component itself hasn't been released). We don't use it for payment notifications as the screenshot might suggest, as that would get annoying very quickly! Instead, my co-founder and I get notifo alerts when anything might be out-of-bounds: daemons not running, load averages, memory usage, DNS/web test queries, various queues, etc. This gets tied in with our internal business dashboard, so we can see warnings before they get to the "failed" state that triggers a notifo, or usually just see a bunch of nice green checkmarks underneath our sales stats!<p>Honestly, after running it for 2+ months, the problem is that it's been <i>too</i> sensitive, so recently the progress has been in adding logic to make it ignore and/or fix and/or retry without notifying us at all. For example, if one of our secondary nameservers is unreachable, my script knows that I don't care, but it will let me know if two or more are down -- and only after trying a few times. And if our Asterisk instance can't talk to our SIP provider, then it will instruct Asterisk to try to reconnect. Another example is in our Django FastCGI processes restarting after serving a bunch of queries (to reduce the effect of process memory growth / leaks): if our script does its checks at that time, it may notice one extra or one fewer process running, so it will wait a few seconds and then check again.<p>At the end of the day, while notifo is only a small piece of the code at this point, it's a core feature that motivated this "autotester" server monitoring script and makes it a must-have for us. We've had it running for long enough that we have fairly good test coverage for all of the moving parts of our server, and over the last few weeks have been able to write some smarts into it so that the frequency of Notifo alerts is small enough that they're usually worth looking into.<p>From a business perspective: This lets my co-founder and I sleep much better and have our mind off of server operations when traveling. That's a real benefit. Thanks, Notifo!