Eric Bergen

Growing up in the world of linux uptime was always considered a good thing. On IRC every once in a while someone would post an uptime. Everyone else in that channel would then check their uptime and if it was greater or close they would post it in the channel. Most of these systems were home linux boxes used for compiling random programs or maybe hosting a webserver for experimenting. It was fun to see how long we could keep them running for. Since those days I have come to realize that high uptimes are a bad thing.
Keeping a server up for months or even years means that you aren’t maintaining it. It hasn’t been kept up to date with new kernels that have fixes for security holes. It doesn’t have new packages or new tools that can help it run more efficiently and have features that can make using it easier. It’s also not up to date with new servers that are being deployed which means that people logging into your server with a high uptime have to adjust themselves to the older software and possible missing tools.

Hardware fails, colos lose power, network connections, and sometimes catch on fire. If you’re entire system depends on a single server, say a mysql master. It’s going to fail. I know there are mysql servers out there that have been up for years. Those are going to fail. It’s inevitable. If you’re system is not designed to withstand the failure of a master it should be fixed. Jeremy Cole and I gave a tutorial at the 2006 MySQL User Conference about MySQL replication and failover. See Jeremy’s blog for links to the presentation and photos.

“But I can’t take down my master to fix it?” It’s much better to do a planned downtime than it is to get paged at 3am because the master died and the whole site is down. Take some time. Plan to take down the master and fix the system. It will be worth it in the end. If your manager says no to a planned downtime to make your website fault tolerant. Find a new job. Preferably at Yahoo!

By building a system that can handle the failure of a master it’s much easier to upgrade MySQL so you can take advantage of all the new nifty features.

The number of cars I saw off the road between ripon, ca and mountain view, ca due to over heating. I went up to ripon today to check out the Stanislaus river as a possible new fishing spot. According to my truck’s thermometer the high temp I saw today was 106F. There are a few steep grades on 580 going through pleasanton. People were working their cars too hard and simply overheated. One of the cars I saw pulled over was a convertible with a couch upside down in the back seat. I’m not sure what they were thinking but they paid for it. Here are some tips to prepare you for the summer heat.

If you see your car over heating turn on the heater and roll your windows down until it cools off. The heater works by running hot coolant from the engine through a little radiator. By turning on your heater with the fan on high you can help cool down the engine faster. Driving down the road with the heater on and windows down is much better than stopped on the side waiting for your car to cool off.
Change your radiator cap and thermostat. These two parts combined may cost you $10. They are well worth it. Radiator caps can wear out and blow prematurely. Thermostats can get stuck closed. Both of these parts are cheap to buy and easy to change yourself.

Check your coolant. Coolant testers are only a few dollars and can save you from a cracked block in the winter or overheating in the summer. Car coolant is a mixture of anti-freeze and water. The ratio of the mix determines the freezing point of the coolant. Coolant testers will tell you the approximate freezing point of coolant. During the hot summer months you can mix your coolant with a little more water to be a little more protected against overheating. Cheap testers will have several colored balls in them. Coolant testers are nothing more than a turkey baster with a few colored balls in them. The balls are a different weight and thus will float with higher density coolant. The number of floating or the color of the floating balls determines the freezing point.

If your going to be driving over hot mountains pack a few gallons of water (no need for anti-freeze) and some rags. If you do over heat pull over, shutdown the engine and wait for the car to cool down. This is important. If you radiator depressurized the water/steam coming out was well over 200F. WARNING!! IF YOU TRY TO OPEN THE RADIATOR CAP WHEN IT’S HOT THE RESULTING STEAM BLAST WILL BURN YOUR SKIN OFF. After the car is cooled down remove the cap with the rags and fill the radiator with water. Close the cap and you should be good to go. If you do fill your radiator with mostly water be sure to have your coolant flushed before winter. Waking up on a cold morning with a cracked block or all your freeze plugs on the ground is no fun.
It also helps to have a truck with a tow package (oversized radiator and transmission cooler)

It always takes me a few tries to get a good flow going on a blog entry. I also _hate_ touching my mouse. In my world every time I have to move my hand over and use my mouse it’s a delay in my work. I would really like to get one of those mice that tracks my eyeballs and uses a short cut key to click. Until then I will continue optimizing everything I do on my computer to use the mouse as little as possible. Back to the point while trying to get a good flow going on a blog entry I always end up writing a few sentences then deleting the last one. I do this by holding down the backspace key. When deleting a word or two I press the delete key the correct number of times but for more than two words I tend to hold down the delete key. In wordpress 1.5 and every other thing I use in my daily life when I let up off the backspace key the deleting stops. In wordpress 2.0 there is some funky jazz going on in the text box that causes the delete events to be slow and thus spool up. When I let up off the back space key innocent characters disappear from the text area. This is not only sad but very frustrating because I have changed my habits to move the mouse, highlight text and press the delete key once.
As I do with everything else on this blog I’m going to rant about the problem before going out and finding a solution. Ranting here first clears my head so I can stop being so upset and actually focus on the solution. Once I find it either (I wrote the word either 4 times. I picked up my mouse, highlighted the previous sentence past the word either and pressed the delete key. I then got upset at myself for acting out that bad habit, wrote the old sentence, held down the delete key, and destroyed most of the word either. I then rewrote it and tried to get the timing down, over shot and destroyed it again.) I will post a new entry or a little [Updated:] block will appear below this post. I’m not sure why I’m talking about my quirky writing habits but it’s been a long day and I feel guilty for not posting anything on here for a while. Not because I think people want to read what I write but because my writing gets worse if I don’t practice.