Computers & Internet

One of the major issue with large data centers is power. This is applicable to both large data centers like Microsoft / Google and also to large Enterprise Data Centers which are very energy inefficient.

Definition of Power Effectiveness: Data Center Power Usage Effectiveness (PUE) is defined as the ration of data center power to IT (server) power draw. Thus a PUE of 2.0 means that the data center must draw 2 Watts for every 1 Watt of power consumed by IT (server) equipment. The ideal number would be 1.0, which means there is zero overhead. The overhead power is used by lightning, power delivery, UPS, chillers, fans, air-conditioning etc. Google claims to have achieved a PUE of 1.3 to 1.7. Microsoft runs somewhere close to 1.8. Most of Corporate America runs between 2.0 and 2.5.

A typical large data center these days costs in the range of $150 Million to $300 Million depending upon the size and location. A 15 MW data center facility is approximately $200 million. This is the capital cost so it is depreciated over time.

Most of the facility cost is power related. Anywhere  from 75% to 80% of the cost is power (pdu, chiller, ups, etc).

A typical 15MW datacenter with 50,000 servers costs about  $6.0 million per month for operating expense (excluding people cost) and the share of power infrastructure (pdu, chiller, ups, etc) is between 20% to 24% and actual power for the servers is 18% to 20%. Thus total power cost is between 38% to 44%. These numbers reflect what Microsoft / Google would do. EPA has done a study and they believe these numbers are close to 50% for inefficient data centers.

If you use Google Analytics’ Site Overlay functionality, it occasionally results in a white or gray haze over your website which prevents you from clicking on any of the links.

The good news is that your browser is the only one affected (none of your customers will see the same effect). All you have to do to fix the problem on your end is clear your cookies (specifically a cookie called GASO).

I’ve been playing around with Wolfram Alpha’s new computational knowledge engine and it seems to need a lot of work before it becomes more than an exotic curiosity. I entered the following query:

US Debt / US GDP

and it returns the following answer:

0.585 years (2007 estimate)

I’m not sure how to interpret that but it seems ominous!

The thought of managing accounts with 450 different ad networks made my head hurt so I signed up with Rubicon Project .  They claim to optimize the ads on your blog and show better performing ads more frequently. It’s been running for over a week on my blog and (as you can probably see on the sidebar to the right), I’m still running public service ads for the Red Cross. The dashboard on Rubicon Project’s website says that it’s still activating, though.

Update: The reason no ads were running is that I had forgotten to add baseline ad tags from Google and Rubicon Project has limited inventory in the 200×200 size that I had chosen (since it fits nicely in my sidebar). Their customer service is very helpful, though, and they were excellent at clarifying what I’d done wrong.

If you want to share video and visual information from your desktop you should check out Dyyno. They have combined some pretty cool video compression technology with a peer-to-peer networking layer and the result is very slick.

Their technology provides the plumbing for Xfire’s live video service. It’s still in beta but if you need a WoW fix, that’s the site to visit.

WebDesignerWall has a great introductory jQuery tutorial. There are ten tutorials, including ones on animated hover effects, collapsible panels and menu accordions.

About two years ago I began to dabble in web development and I finally understand why the cognoscenti loathe Internet Explorer. On both of my websites, things just seem to work consistently across Firefox, Safari and Chrome (my browser of choice for its blazing speed). On IE, though, there are invariably a whole slew of layout problems and different interpretations of what I’m trying to achieve. Things seem marginally better in IE8 but many of the problems persist.

Hopefully, as IE’s market share declines, Microsoft will be forced to conform to the standards.

ssh-keygen -t rsa

Then use this command to push the key to the remote server, modifying it to match your server name.

cat ~/.ssh/id_rsa.pub | ssh user@hostname 'cat >> .ssh/authorized_keys'

The following gems and plugins are the most popular as of Nov 12th, 2008:

• Javascript Framework: jQuery (56%), Prototype (43%)
• Skeleton: Bort
• Mocking: Mocha
• Exception Notification: Hoptoad
• Full text search: Thinking Sphinx
• Uploading: Paperclip
• User authentication: Restful_authentication (keep an eye on Authlogic)
• HTML/XML Parsing: Hpricot
• View Templates: Haml

NewRelic has a good article on the state of the Rails stack.

I’ve been watching the Olympics on TV Tonic’s platform. NBC collaborated with TV Tonic to provide viewers with the ability to watch the Olympics over the internet.

Some scattered thoughts in no particular order:

1. It’s great that NBC has finally realized that some of us want to watch the Olympics over the web and this is a huge leap forward from prior years.
2. NBC apparently managed to sell ad space to only one company: Lenovo. I used to contemplate buying a Lenovo laptop. After watching the same ad 15-20 times a day I can now say I will never buy a Lenovo laptop.
3. It’s great to be able to watch sports sequentially. I no longer have to have gymnastics coverage interrupted with rowing. Far less time is wasted.
4. The user interface becomes somewhat unuseable after a while. It’s difficult to see which events you’ve watched, they don’t always seem to appear in chronological order. Also, it would be nice to be able to remove the heats and only download the finals. Even better would be able to specify exactly which events to download rather than having NBC decide for us.
5. I realize that nothing is live for us poor saps in the USA but posting the content more than 24 hours later makes a mockery of the idea of live sport.
6. It’s a pity the water polo isn’t broadcast in higher definition. The compression algorithm completely choked with all the water and the end result is that you can’t see the ball. That detracts from the experience but leads to my next point…
7. We all want HIGH DEFINITION. You’re making us wait until the next day to watch the events everyone was talking about at work….at least give it to us in high definition. People watching the Olympics over the web have a decent setup. You should cater to them or risk ending up on the scrap heap of failed internet video start ups.
8. Those Chinese gymnasts definitely aren’t 16. (That was obvious even on the low def video that NBC slopped up to us.) Let’s call it what it is: CHEATING
9. Phelps is a legend in any quality video.