What does four 9's mean?

Skip Cole

Ranch Hand

Posts: 177

posted 16 years ago

my test has the phrase that says something to the effect of they will be available four 9's. What does this jargon mean? Anyone know?
Thanks,
Skip

If you love me, you will visit docs.opensimplatform.org
(FYI, Getting it tattooed on is a bit much.)

John Wetherbie

Rancher

Posts: 1449

posted 16 years ago

"Four nines" is a way of saying 0.9999. In the context I am used to it means that the availability (or reliability) will be 99.99% or that there will only be one failure per 10,000 units of measurement, whatever they may be.
John

The only reason for time is so that everything doesn't happen all at once.
- Buckaroo Banzai

Skip Cole

Ranch Hand

Posts: 177

posted 16 years ago

Thanks!

If you love me, you will visit docs.opensimplatform.org
(FYI, Getting it tattooed on is a bit much.)

Danl Thompson

Ranch Hand

Posts: 93

posted 16 years ago

But it also tells you that there will be failures. On average 20 per day. So you must consider how your design will handle this.
Dan'l

It is sorta covered in the JavaRanch Style Guide.

What does four 9's mean?

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