Reliability

What is reliability?

Reliability, R is the probability that the service will perform its functions for a specified time. R measures how the service performs under varying operating conditions.

We often use Mean Time Between Failures (MTBF) and Mean Time To Repair (MTTR) as the metrics to measure R.

$MTBF = \frac{Total\ Elasped\ Time - Sum\ of\ Downtime}{Total\ Number\ of\ Failures}$ ...