Smaller Longview Plans

Montastic offers simple and cheap (or free) monitoring plans.

Only checks a few things, but for free (or $5/month) it's better then nothing.

I really like munin but sometimes it surprised me with how resource intensive it could be, not to mention what you experienced (occasional tweaking to get it running again).

New Relic (newrelic.com) now offers a free plan that doesn't suck. It might not be obvious from the marketing blurbs but it will do server uptime monitoring, you configure it via the applications as opposed to a server list. In other words, you put the new relic tools into your ruby/python/php/etc. app and stats for that app will show up on your dashboard. From that dashboard you can turn on external monitoring of that app. Generates very nice uptime reports and if you upgrade from the free plan it does very nice SLA reporting and graphs. The main drawback on their free plan is only 24 hour retention of data.

CopperEgg (copperegg.com) also has a free plan, but I didn't really like it that much… I think their target market is companies with gobs of servers and it doesn't really "scale down" to the handful of servers I run.

I've also tried free Yottaa (yottaa.com) but didn't like it and they continued pinging my servers even after I deleted all of them from my account. Not cool.

I'm just now getting ready to try Datadog (datadoghq.com) which I've heard good things about… will post back in a couple weeks if I like it.

I will also probably try Longview at some point just to make sure I'm not missing anything but I think it's a little behind the times. New Relic and Datadog both give us better visibility into our application internals, not just the server. You don't get that with munin either, but you do if you're willing to dive into the world of statsd + graphite.