How many nines are there in high availability?

How many nines are there in high availability?

Percentage calculation
Availability %Downtime per yearDowntime per week
99.995% ("four and a half nines")26.30 minutes30.24 seconds
99.999% ("five nines")5.26 minutes6.05 seconds
99.9999% ("six nines")31.56 seconds604.80 milliseconds
99.99999% ("seven nines")3.16 seconds60.48 milliseconds
12 more rows

What percentage is high availability?

High availability is measured as a percentage, with a 100% percent system indicating a service that experiences zero downtime. This would be a system that never fails. It's pretty rare with complex systems. Most services fall somewhere between 99% and 100% uptime.

How many 9's of availability are required?

five nines The accepted availability standard for emergency response systems is 99.999% or “five nines” – or about five minutes and 15 seconds of downtime per year (see table below). To achieve five nines, all components of the system must work seamlessly together.

What does 5 nines mean?

Availability is normally expressed in 9's. For example, “5 nines uptime” means that a system is fully operational 99.999% of the time — an average of less than 6 minutes downtime per year. The chart shows what impact various availability levels have on your server downtime.

What does 3 nines mean?

Because over the course of a year, 99.9% uptime—or “three nines”, in industry terms—adds up to more than eight hours of unplanned downtime.

How can I get high availability?

Here are some of the key resources you can implement to make high availability possible:

1. Implement multiple application servers. ...
2. Scaling and slaves matters. ...
4. Maintain a recurring online backup system along with hardware. ...
5. Use of a virtualized server for zero-downtime recovery.

What does 4 nines mean?

·4 min read. Let's start with what 4 9's means exactly: Four Nines is 4.38 minutes downtime per month, or 52.56 minutes per year. That's probably more than acceptable for almost all services on the Internet, not all, but almost all. So your email is down for 4 minutes each month, not the end of the world.

What is 99.99 availability?

Five-nines or 99.999% availability means 5 minutes, 15 seconds or less of downtime in a year. Four nines or 99.99% availability allows 52 minutes, 36 seconds downtime per year. ... One nine or 9% availability allows over 332 days of downtime per year.

What does 5 9s mean?

99.999% Five nines, commonly taken to mean "99.999%", may refer to: High availability of services, when the downtime is less than 5.26 minutes per year.

How often do you have a five nines availability?

Five nines availability, which means only five minutes of downtime per year, is ambitious. There is probably not one company that currently hits this standard. But as more and more critical services come online, it's reasonable to assume that the industry will shift toward higher standards, especially given the costs of downtime.

How much down time can you get with four nines?

Otherwise, four nines or 99.99% availability allows 52 minutes, 36 seconds downtime per year. Three nines or 99.9% availability allows 8 hours, 46 minutes downtime per year. Two nines or 99% availability allows 3 days, 15 hours and 40 minutes downtime per year. One nine or 9% availability allows over 332 days of downtime per year. That's right.

Which is the best percentage for high availability?

The most popular of the lot, 99.999%, is the five-nines of availability This chart describes how each Availability percentage correspond to the yearly, monthly, and weekly downtime: How do you achieve high availability?

What does 5 nines mean in network reliability?

Five Nines ( 5 nines) is an industry benchmark long used to describe highly reliable telecommunications systems and network equipment. Here's how it's calculated and what it means to your service uptime. Five nines reliability. It's the standard often quoted for traditional telephone service and top network equipment vendors.