Category: technology

2 new gimmicks for Christmas

So Rhian and I decided that we would order some things we wanted for ourselves for Christmas. I choose to get a Timex Ironman GPS watch since my last training watch a polar has to go back for repairs. For a lot of reasons I didn’t like the polar that much. Compared to my timex watches it always felt as if the polar was a bit more flimsy. It got scratched up while working out, which considering the hell I put my timex through have never been scratched. Really makes me wonder if the Polar is meant to go through the same usage. Luckily from what I have seen they have a great guarantee program. So the watch can be send back and the screen and the strap will get fixed.

The 2nd gimmick was a bose headphone with noise cancellation. Considering my ability to break or wash headphones I want to see how well this headphone lasts.

Fencing on clusters

So I will write one of my few tech blog posts. Yes I know, a rarity. Linux clusters are pretty common place these days. redhat clustering is just 1 of the several ways to achieve it. The one thing that I have found out the hardway is always , always check if the cluster you are working on has fencing. If it doesn’t have fencing , set it up immediately. Basically a HA cluster without fencing is the equivalent of not having HA.

fencing is a very simply concept. All it means is that if server A notices server B in the cluster has issues, it can reboot or power it off using a lights out management system (could even be drac) . Even the most simple fencing of shoot-the-other-node-in-the-head gives you a lot of stability.
So lesson learnt setup fencing. Test fencing.

Subversion case in-sensitive files

I have been using subversion for the last 5 years. It is pretty standard code repository tool. And I have started liking it better than cvs, mcvs , it still doesn’t match up to bitkeeper . But it does the job.

Well recently I just imported in 5000 files into our work svn. We were moving servers and had decided to move some specific files into the code repository. All worked really well. Until one of the developers alerted me to error “Can’t copy / ….. ‘ . Well intially I thought it was just bunch of corrupted svn files. As it turns out it isn’t . SVN can’t handle files with the same name, but with different case . I want to say “which world are these people from ??” http://tortoisesvn.net/node/167. Even windows now sees better times than this.

The issue as they explain is that since Windows (yeah blame it on Microsoft) doesn’t support case-sensitive files, therefore they can’t . Ok . Fine good enough.Except

1. If you can’t support case-sensitive files of the name, then don’t let me import or add them. Logic would say it is an error to Add that.

2. Change the error message !!.

3. I mean seriously the better fix is allow files of the same name but with case-sensitivity . If I am *nix then it should work. Doing an update from windows should give this as an error. So then the svn client deals with it.

So maybe #3 isn’t ideal but atleast do #1, #2

The straw that broke the camels back

Everyone has a breaking point. You find different breaking points while training. Your breaking point on the run, the bike at work, and then your mental breaking point. My breaking point was a $100 training watch which broke during my swim in placid. Who would have thought. I felt naked without a training watch. I drove R insane talking about. I wanted a new watch asap, I needed a watch.
I was debating a watch that would work with a power meter . Also after rich mentioned he would kick our ass if we had race wheels and no power meter , I figured I didn’t want to make that mistake. I finally gave in and bought a polar watch just to keep my sanity. It would get delivered before I left for dc.

Race Rehersal

First day of camp and a bunch of us have to do a race rehearsal. We meet up at high peaks cyclery and weather gods are having a laugh at us. It is slightly colder and most of us need an extra layer. We head out of town and do the modified bike course. I do a 3:10 on e first loop. Get back into town take a break for 10 min and then head out again. The next loop I am somehow with a faster group of riders ( don’t know how that happened) . On the 2nd loop I decide to skip the 2nd outback. On the way back from Wilmington the sun is out and I am cooking in e extra layer that I have on. I get back into town and I stow the bike . The second loop was slower around 3:29. I curse myself for riding a 6:30 split I was meant to do an even 6:00.
Either way I have done 109 miles and just want to get off the bike. I would have been willing to sell my bike for $1 if I didn’t need it for the race. I start off on the run with Keith . We are doing a nice 9min/mi after 3 miles I pick it up to race speed. Run down the hill flip it around and run back into town

Facebook and Privacy (round2)

Ok I am not the guy with the tin foil hat. But facebook is seriously ridiculous when it comes to introducing new privacy settings. And this is the second time they are going about this.

They have now added a new setting Instant Personalization. Which is by default On for all users. The setting allows all websites using the facebook api’s to get, share, update information about you. So now all of the browsing on different websites I visit is a great social experience that I get to share with everyone in the world. Everything on each of their partner websites from cnn , yelp , pandora will now not only be able to update your facebook info , but also will be able to get your information. Just what I want facebook the overlord of my information on the web. NTY!

It is not even an option which websites I want to opt into this. So it is an all or nothing. Great. facebook is one of the few websites/applications that I don’t use that often and every once in a while they introduce something that requires me to go change more settings. Has their product team ever heard of the UI concept of Reasonable Defaults!

Physics will get you

So working in technology I am always surprised when people forget basic physics and how it applies to our everyday lives. Being a physics student in college there are certain things I will probably never forget; newtons laws, speed of light, theory of relativity, power calculation, electricity calculations, and my personal favorite the wave equation.

So a couple of things that I think we need to remember from everyday physics:

1. Theory of relativity: simplified only light can really travel at “speed of light”. electrons and electricity , and correspondingly network packets over ethernet travels no where close to the speed of light.

electricity on a typical high shielded coax cable is roughly 2/3 speed of light.more relaistic is that it travels at 1/3 speed of light . not to get into the intricacy of physics but rest-assured an electron will never travel at the speed of light. unless ofcourse you in star-trek land .

2. Optics: Even though fiber optic is dependent on light transmission , the actual speed of the signal on fiber optic is not the speed of light. first of all speed of light is absolute in a vaccum. fiber optic is not a vacum.second the speed of the signal is effected on defraction, reflection , dispersion so in actuality it is never travelling over a given distance at the speed of light.

But thats ok. Don’t go selling stock of alcatel, lucent engineers are smarter they send several signals over the same fiber. so in that way the total throughput is a lot more. but at the same time 1 signal still has physics governing it.

3. The speed of light even if transmitted across the US is still going to have a ping time of 1.3ms. So basically you can take a beam of light and send it across the US, it takes 1.3ms for another person to see it. Again this is my back of the paper of calculation.

4. Ping-Pong: The avg time taken for signal to be sent and to get a reply back, can be calculated by ping-pong test. You simply send a signal and wait for the reply. The time take divided by 2 is the time taken for your signal to be sent.

5. Electrical power: Let do some simple calculations first

Power=Voltage x Current

So if your server takes 200 watts of power at 110 volts , it is 200/110 amps as draw.

WP ImageGallery

I think everyone would agree that getting images, and image gallery into your blogs is crucial. At some point people would get sick of reading just our words. So when I started using wordpress I just “ass-umed” that it had an easy interface to upload and edit images, and to create an image gallery.

I might be considered biased since for my day job I create a CMS which does that. But realistically if someone can argue that creating and uploading an image gallery in WP is “easy” then I would like to hear it. Here was my experience. Continue reading “WP ImageGallery”

Birds like Iphones

So while on my trip to b-town I decided birds like iphones. As an interesting anecdote while I had gone out for my 12mi run rhian decided to go get coffee and do the regular sunday morning rituals. While walking back and using google maps to direct her, a feathered friend decided to do its business with amazing accuracy on the iphone. Hence my thought that birds like iphones.

If you look at it, and if birds had the cognitive thought and the control to choose their targets they would be classified as being amazingly more accurate than most modern fighter planes , including predator drones. So why doesn’t the CIA take a look at that. They are hell-bent on using drones to eliminate single people targets , while trying minimize collateeral damage. Then why not use small toy planes mounted with single rounds of low caliber guns to eliminate them.

Seriously to consider a hellfire II missile with blast fragmentation, costs roughly $65,000 has a blast radius of over a 100meters all to eliminate 1 person. I am big fan of the philosiphy “use the right tool for the right job” , I think someone made a bad choice.