It looks like not guaranteeing 100% uptime is becoming a trend:

  • Microsoft Photosynth was inaccessible for several hours after official launch.
  • Twitter’s downtime has become a story by itself. Many people think that’s because they use Ruby on Rails.
  • Draugiem.lv, Latvia’s largest social network, had constant uptime problems during first years of operation. By the way, it’s PHP-based.
  • One.lv, another popular social network in Latvia, is down for several minutes every night. It’s written in Java/GWT.

And now I see something from a website which is supposed to be always up. After 1 second delay at log in, Google AdSense displays this message:

Google AdSense is Down

http://www.google.com/errors/asfe/system_down.html

UPDATE Aug 24 2008: The service is up now. Instead of using traditional practice of showing maintenance times on out of service page, Google posted this on their blog:

This Saturday, August 23rd, our engineers will be performing site maintenance from 10am to 2pm PDT. You’ll be unable to log in during these hours, but we’ll continue to track your earnings and serve ads to your pages. For those of you located in different time zones, we’ve provided the maintenance start time for a few international cities:

London – 6pm Saturday
Istanbul – 8pm Saturday
Bangalore – 10:30pm Saturday
Hanoi – 12am Sunday
Auckland – 5am Sunday

Finally, you may have noticed that we’re posting this message a little earlier than usual. Based on your feedback, we’ll do our best to post these maintenance reminders earlier in the week to help you plan ahead. Thanks for the suggestion!