In this age of web 2.0ism’s, developers prefer flexibility of innovation to reliability. Building reliable systems becomes more important as an application begins to mature.

@JonK - yep, you’re right. Thanks for pointing that out.

@Mike Nolet - good point. For most high traffic sites every hour is peak hour given the global nature of Internet traffic.

See, the post in question is from April *2007*: in other words, those numbers are for the first three months of last year, in which case 5 9’s would look something more like 80-odd seconds and everyone bar Yahoo gets a resounding helping of FAIL.

There are just too many factors outside of the control of any services provider or enterprise like peering or routing issues between the data center and the user/customer.

Of course, with the appropriate software, equipment and procedures it should be possible to achieve five 9s from the point of demarc where the computing resources connect to the public network. Assuming you are choosing the appropriate two of the good, fast and
cheap set as mentioned above.

Probably the best place to start is to begin to understand the end-to-end experience you are currently delivering using the appropriate website monitoring technology.

Interesting to note, even Amazon’s S3 online storage has only promised 99.9% uptime: (link) .

@Rodrigo - yes, fast page load (preferably faster then the mythical 8 second human patience limit) is necessary. Websites that are down load in an infinite amount of time.

@Paul - I don’t recall my Internet access being down almost 9 hours last year. The FB, Google and S3 outages are a major issue - how long do we have to endure their suckiness?

The 99.999 is really reserved for airplanes backup systems, safety equipment and medical equipment like pacemakers.

it’s not that the web is seen as less reliable it’s just that the world have always been like that, 99% uptime is better then most railways. The fact that were even talking about 99.99% uptime on web pages tell the exact opposite picture, people see the web as more reliable then the real world.

Second: As the six sigma folks figured out, a complex six sigma final product requires its components to be orders or magnitude (more 9’s) more reliable, redundant, or both.

When Facebook wants to be the web’s user directory, and Google wants to be its directory, and Amazon is pitching to be its storage system, outages (and upgrade incompatibilities) will stack. It will suck for a while at least, as anyone who has tried to retrieve a United Airlines itinerary at the last minute can probably understand.

It’s not just a matter of being up/available. The site has to be usable. It not only has to be up and fast, it has to be consistent. It has to be efficient.

As we have seen with a number of fast growing social networking businesses / projects, there is a struggle to cope with exponential user growth and system scalability. I am not an expert in these areas; I am an analyst who reports on the times where this does not work.

Allan wrote earlier about the madness that occurs when you ignore the network. Now he is pointing out that systems are human creations.

99.999% is nearly impossible. The objective is to aim for a site that is consistent, predictable, and treats it’s customers as rational human beings, not “users”.

@spierzchala