Data Centers and uptime is assumed.  Service Level Agreements (SLA) are made between groups.  But, many times there are exceptions for planned maintenance/downtime vs. unplanned downtime when calculating SLA.

InformationWeek reports on Google Apps/Gmail's change to this common practice.

Google Promises No Planned Downtime

A new service level agreement (SLA) for Google Apps customers strives to make Google's cloud as reliable as dial tone.

By Thomas Claburn ,  InformationWeek
January 14, 2011 02:42 PM

Google has changed its service level agreement for paid versions of Google Apps, its suite of online applications. The goal, says Google Enterprise product management director Matt Glotzbach, is to deliver service that's as reliable as telephone dial tone.

For today's mobile generation, who may lack experience with landlines, let it suffice to say that dial tone under Ma Bell was very, very reliable. Not sunrise reliable but chances were if you didn't hear a dial tone when you picked up a handset, the phone was disconnected from the wall.

Google is taking a leadership position.

But with millions of enterprise customers, Google aims to become more reliable. As a sign of its commitment, the company has disavowed planned downtime. "Unlike most providers, we don't plan for our users to be down, even when we're upgrading our services or maintaining our systems," wrote Glotzbach in a blog post. "For that reason, we're removing the SLA clause that allows for scheduled downtime."

Glotzbach says Google is the first major cloud service provider to make that pledge.

In Google's blog post they call out the competition.

Gmail: 99.984%
In 2010, Gmail was available 99.984 percent of the time, for both business and consumer users. 99.984 percent translates to seven minutes of downtime per month over the last year. That seven-minute average represents the accumulation of small delays of a few seconds, and most people experienced no issues at all. For those few who were disrupted for a longer period of time, we're very sorry, and Google Apps for Business customers received compensation where appropriate. We're particularly pleased with this level of reliability since it was accomplished without any planned downtime while launching 30 new features and adding tens of millions of active users.
Seven minutes of downtime compares very favorably with on-premises email, which is subject to much higher rates of interruption that hurt employee productivity. The latest research from the Radicati Group found that on-premises email averaged 3.8 hours of downtime per month. In comparison to Radicati's metrics for on-premises email, our calculations suggest that Gmail is 32 times more reliable than the average email system, and 46 times more available than Microsoft Exchange®.¹

Fortunately Microsoft Exchange® customers can still benefit from the reliability of Gmail withGoogle Message Continuity. Comparable data for Microsoft BPOS® is unavailable, thoughtheir service notifications show 113 incidents in 2010: 74 unplanned outages, and 33 days with planned downtime.

You may be thinking I can't do this in my data center.  And you are right you can't.  This solution requires geo redundancy between data centers.  For a bit on some of Google's approach check out this Google presentation at Stanford University.

Google – A study in Scalability and A little systems horse sense

By ksankar

16 Votes

Google’s Jeff Dean did an excellent talk at Stanford as part of EE380 – it is worth one’s time to listen. Very informative, instructive and innovative. As I listened, I jotted a few quick notes.

• Interesting comparison of the scale in search from 1999 to 2010
  • Docs and queries are up 1000X, while the query latency has decreased 5X
  • Interesting to hear that in 1999 they used to update a web page store in a month or two, but now it is reduced 50000X to seconds!
• They have had 7 significant revisions in 11 years
• Trivia : They encounter very expensive queries for example “circle of death” requires ~30GB of I/O
• Trivia : In 2004, they did a rethink and refreshed the systems infrastructure from scratch
• He discussed a little about encodings – informative discussion on Byte aligned variable length & group encoding schemes << I have to try it out …
• Trivia : They have had long distance links failure by wild dogs, sharks, dead horses and (in Oregon) drunken hunters !

The presentation referenced is by Jeff Dean.

I wrote last week on What could Google do with 111 Eighth Ave building? A new bargaining chip

Another idea that just popped into my head is Google could turn 111 Eight Ave building into a change agent for the carrier hotels, Internet Exchanges, Peering, and who knows what else they want to drive in the industry.

The current model of carrier hotels are run by private enterprises or a non-profit like AMS-IX.

Vision

AMS-IX: the trusted value creator in quality IP interconnection [^1]

Mission

1. To realize the principal, neutral IP interconnection marketplace worldwide

2. To offer world-class quality performance and operate a future proof platform to secure the growth of IP traffic between connected parties

3. Support initiatives for the good of the Internet to ultimately improve end-user experience

Values

• Neutral
• Trusted
• Pragmatic
• Open
• Innovative

Equinix is an example of private Internet Exchange site.

When our founders started Equinix, they envisioned a place where the information-driven world could grow and thrive.

As the company looks forward, we remain dedicated to the advancement of the information-driven world. This means that we will:

• protect and connect our customers’ most valuable information assets;
• constantly strive to evolve and share our industry insights with our customers;
• continue to make necessary investments to expand and scale to our customer's needs;
• act upon industry trends that will affect our business and the businesses of our customers;
• cultivate a rich interconnected ecosystem of the top networks, carriers, ISPs, and business partners in the world.

What happens when Google takes their money, knowledge, and strategic vision and demonstrate to the rest of the industry the way they want carrier hotels to operate?

Don’t just think of Internet technology, think of different business models as well.  Many ideas have failed because of the business model, not the technology.

Google has 24 Public Peering Exchange Points in Equinix facilities.  The largest amount dedicated to any one company.  Don’t you think 111 Eighth Ave changes the conversations between Equinix and Google?

Google has sponsored projects like Google Fiber for Communities.

Google Fiber for Communities: Next steps

The deadline for responses to our request for information has passed. We will announce our target community or communities by the end of the year. In the meantime please visit fiberforcommunities.com to learn how to take action to improve broadband where you live.

Since we announced our plans to build experimental, ultra high-speed broadband networks, the response has been tremendous. Hundreds of communities and hundreds of thousands of individuals across the country have expressed their interest in the project. We're not going to be able to build in every interested community - our plan is to reach a total of at least 50,000 and potentially up to 500,000 people - but we hope to learn lessons from this experiment that will help improve Internet access everywhere.

We humbly thank each and every community and individual for taking the time to participate. If one message has come through loud and clear, it's this: people across the country are hungry for better and faster Internet access.

This map displays where the responses were concentrated. Each small dot represents a government response, and each large dot represents locations where more than 1,000 residents submitted a nomination. A list of government responses is available here.

Seems natural Google would want to change the Internet Exchanges as well.