Month: September 2021

Understanding SLA vs Downtime

Understanding SLA (Service Level Agreement) is very important after you choose to start from scratch OR migrate your application to Cloud.

You can find the SLA provided by Microsoft for its Azure services here.

Usually the SLAs will be 99.9 (three9s) to 99.999 (five 9s). At a first glance, you can think there is not a major difference in them. However when you are hosting a production application, it is very important to understand what the 9’s really mean w.r.t the downtime.

Here is a table for you to understand SLA vs Downtime

SLA percentageDowntime per weekDowntime per monthDowntime per year
991.68 hours7.2 hours3.65 days
99.910.1 minutes43.2 minutes8.76 hours
99.955 minutes21.6 minutes4.38 hours
99.991.01 minutes4.32 minutes52.56 minutes
99.9996 seconds25.9 seconds5.26 minutes