Most hosting providers promise 99.9% uptime. But what does that actually mean?
The math
99.9% uptime allows a maximum of 8 hours and 46 minutes of downtime per year, or about 43 minutes per month.
Scheduled maintenance
Planned maintenance (hardware upgrades, security patches) typically does not count toward the SLA calculation.
What causes downtime?
Hardware failures, DDoS attacks, network issues, or software bugs. A good provider has redundant hardware and DDoS protection.
