[vilpponen]

Thanks for the comment! A 100% SLA is actually a promise of future uptime. Nobody can of course guarantee their uptime, no matter what the SLA percentage. Thus, the company includes compensation in the agreement if the service level is not met. All this of course is decided based on historical data and what makes business sense for the company, ie. how much money are they willing to lose if their services go down.

[NDizzle]

Would you buy a car that guaranteed to never break down? Do you not understand how ridiculous a 100% uptime claim is?

I don't even consider companies stupid enough to put out a blurb like that.

[michaelbuckbee]

The key here is that that is for a SLA. So it's not that they'll never be down, but rather for every minute they are down they'll pay out money to you for the trouble.

To extend the car analogy, it's more like a lifetime warranty on a car: the car might break down all the time, but its still covered.

[tbrownaw]

How is it ridiculous?

They're explicitly not saying that it will never go down. They're saying that if it ever does go down, they will pay their customers a penalty. Without having any "acceptable" amount of downtime that they don't have to pay a penalty for.

Really, too-many-9s SLAs are what's ridiculous. So you say you "guarantee" 99.99% uptime, but only interruptions of 30min or more actually count? 2 incidents of 29 minutes would put you over that .001% that you claim, without either counting.

[vilpponen]

I would definitely buy a car if they advertised it to never break down - if the compensation on the promise would be good enough!

But seriously speaking, a 99.99% SLA is not more realistic or achievable in itself than any other SLA promise. It all depends on the provider (how they strive to reach that promise) and what they promise in return if the promise is broken.

[lvh]

Nobody claims they will give you 100% uptime. The service level agreement is at 100%, that just means that the service should be up 100%; when it isn't, you get compensated. They're saying that any percentage of downtime (modulo time limits) is bad, not that it won't happen.