In 1935, Austrian physicist, Erwin Schr\u00f6dinger, still flying high after his
\nNobel Prize win from two years earlier, created a simple thought experiment.<\/p>\n
It ran something like this:<\/p>\n
If you have a file server, you cannot know if that server is up or
\ndown…until you check on it. Thus, until you use it, a file server
\nis\u2014in a sense\u2014both up and down. At the same time.<\/p><\/blockquote>\nThis little brain teaser became known as Schr\u00f6dinger’s File Server, and
\nit’s
\nregarded as the first known critical research on the intersection of Systems
\nAdministration and Quantum Superposition. (Though, why Erwin chose,
\nspecifically, to use a “file server” as an example remains a bit of a
\nmystery\u2014as the experiment works equally well with any type of server.
\nIt’s like,
\nwe get it, Erwin. You have a nice NAS. Get over it.)<\/p>\n… Okay, perhaps it didn’t go exactly like that. But I’m confident it would
\nhave…you know…had good old Erwin had a nice Network Attached Storage
\nserver instead of a cat.<\/p>\nRegardless, the lessons from that experiment certainly hold true for servers.
\nIf you haven’t checked on your server recently, how can you be truly sure
\nit’s running properly? Heck, it might not even be running at all!<\/p>\nMonitoring a server\u2014to be notified when problems occur or, even better,
\nwhen problems look like they are about to occur\u2014seems, at first blush, to
\nbe a simple task. Write a script to ping a server, then email me when the
\nping times out. Run that script every few minutes and, shazam, we’ve got a
\nserver monitoring solution! Easy-peasy, time for lunch!<\/p>\nWhoah, there! Not so fast!<\/p>\n
That server monitoring solution right there? It stinks. It’s fragile. It
\ngives you very little information (other than the results of a ping). Even
\nfor administering your own home server, that’s barely enough information and
\nmonitoring to keep things running smoothly.<\/p>\nEven if you have a more robust solution in place, odds are there are
\nsignificant shortcomings and problems with it. Luckily, Linux
\nJournal<\/em> has
\nyour back\u2014this issue is chock full of advice, tips and tricks for how to
\nkeep your servers effectively monitored.<\/p>\nYou know, so you’re not just guessing of the cat is still alive in there.<\/p>\n
Mike Julian (author of O’Reilly’s Practical Monitoring<\/em>) goes into detail on a
\nbunch of the ways your monitoring solution needs serious work in his
\nadorably titled “Why Your Server Monitoring (Still) Sucks” article.<\/p>\nWe continue “telling it like it is” with Corey Quinn’s treatise on Amazon’s
\nCloudWatch, “CloudWatch Is of the Devil, but I Must Use It”. Seriously,
\nCorey, tell us how you really feel.<\/p>\nWith our cathartic, venting session behind us, we’ve got a detailed, hands-on
\nwalk-through of how to use Monit (an open-source process supervisor for
\nLinux) coupled with RRDtool (a GPL’d tool for capturing data over long
\nperiods of time, such as from shell scripts, and graphing it) to monitor your
\nserver in a fairly simple, and very open-source, way.<\/p>\nRound that out with an interview with Steve Newman (one of the folks who
\ncreated Writely, which you might know as Google Docs, following Google’s
\nacquisition in 2006) on his company, Scalyr, which handles server monitoring
\nand log management\u2014and you’ve got more server monitoring information than you can shake a stick at. Or, you can go back to guessing if the cat is still alive. That’s fun too.<\/p>\n