Over the years I have seen uptime stated as part of service level agreements for a wide range of services, from internet connections to web hosting and online applications. When picking a solution with a service level agreement, it is important to check that the details meet your requirements
Reviewing the Service Level Agreement (SLA) is often the last thing on your mind when selecting a solution after ensuring it meets your requirements. On reading SLAs it is important that you understand the acceptable downtime and how this may affect your business.
99% uptime may sound acceptable, but in actual downtime this is over 3 full days downtime per year. It is important to calculate the actual possible downtime. In most cases the uptime is higher and just set lower to ensure the service provider can meet the requirements.
Before you go out thinking that you need 99.999% uptime, it is important to understand that the cost of providing more uptime will cost much more. Selecting the level of uptime needs to be balanced against the cost.
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