Thursday, October 05, 2006

Broken computer stuff completely sucks.
Of course, it also largely pays for what my family and I lovingly refer to as "living indoors", so I guess it has its upsides.
Our CIO stopped by my cube earlier this week and knocked. What CIO knocks? Also, there is no door, so he had to knock on the piece of plastic that tacks down the carpety stuff I like to stick pins in.
He asked me if I was monitoring "Context Switching" on the server farm.
Never, in a decade, has anyone ever asked me about context switching. Hell no, I'm not monitoring for it. No one has ever cared. I thought I was the only one who even found it interesting.
Windows native monitoring (and most third party monitoring add-in like sysmon and perfmon (which are considerably less third party since Microsoft bought them)) look at processor load and memory utilization. It takes very specialized monitoring tools to even notice context switching, much less analyze trends related to it.
In general a Context Switch is something that is at the core of a multitasking operating system, as it is in fact the switching from one application running on the computer to the other. A CPU can actually do only a single task at a time. Sure, it can do a lot of them in a second so it looks like its doing various things at the same time but down-level you can only use the hardware registers once. Intel's Hyperthreading tries to cheat around on this but in the end the CPU is still doing a single task at once.
Let's say your CPU is currently executing a program that is part of MS Word, now on your Citrix server this will not be the only application available so MS Excel is also running. The operating system wants to give Excel its slice of CPU cycles so it switches between the two. What happens is that the CPU registers in use by MS Word are written to memory, afterwards the CPU registers that MS Excel has been using are copied to the CPU. When these are in place the task the CPU is supposed to be doing will be executed.
Stack up 40 users worth of these and you can see where there might be a lot people spending time staring at the spinning hourglass. Oh, how I hate that hourglass.
The earlier indicator of excessive server load is memory utilization and processor activity. These are easy to track.
Citrix has an optional module that checks for context switching issues and (within five minutes) my CIO was proven correct.
That was a long way to go for a short conclusion. I apologize. As compensation, please feel free to discuss Context Switching at your next dinner party. I'd suggest just after the salad course.
He told me I'd been budgeted for more servers next quarter and wants a full and detailed plan for what I'd do to "fix" our solution. Our little group of servers will probably double.
I'm pretty happy about that.
But I still hate broken computer stuff.
Like our router at home.
Apparently, "wireless" in the case of our router refers to the need to walk upstairs every ten minutes and pull the power "wire" out of the back to reboot the thing.
I've made public my plans to smash it with a brick when the new router shows up. Smash smash smash smash-ity smash. Last night I picked out the lucky brick.
I updated the firmware, switched the channel, altered the "mode" and gave the router every possible chance to maintain our connection to the internet. All I want to do is download some podcasts and surf the internet. iTunes freaks my router out like I'd freak if someone dumped a bucket of live spiders on me.
Mmmm . . . bucket of spiders. I could have a lot of fun with a bucket of spiders.
A tightly sealed bucket of spiders. With a very very long handle. Maybe remote control.
You know, I should probably just wait a few years. I hear the Japanese are developing spider-filled robots in a secret bunker somewhere in Okinawa. I could probably pick one up cheap after they use them to completely immobilize every military force on the planet to return the Sony empire to glory.
I, for one, hope our spider-launching robot overlords can find a use for me growing sushi rice somewhere quiet. Hopefully hydroponic rice, since I hate to get stuff on my hands.


Andrew Moore said...

Dude - you eat sushi? You won't eat manicotti, but you'll eat sushi?

Garrick said...

Manicotti is far too disturbing. It isn't like anyone ever wrote a play about making sushi with a . . .

Ok. I'm out.