Measurement, Monitoring & Sharing

The four key DORA metrics used to measure DevOps performance include which of the following sets?

• ACPU usage, memory usage, disk space, and network latency
• BLines of code written, number of meetings held, total open bug count, and percentage server uptime
• CDeployment frequency, lead time for changes, change failure rate, and time to restore service✓
• DQuarterly revenue, team headcount, customer satisfaction score, and total marketing spend per campaign

Answer: The four DORA metrics are deployment frequency, lead time for changes, change failure rate, and mean time to restore service, which together measure both throughput and stability.

What is the main difference between monitoring and observability?

• AMonitoring is manual while observability is impossible to automate
• BThey are identical concepts with different names
• CObservability applies only to hardware, monitoring only to software
• DMonitoring tracks known, predefined conditions; observability helps understand unknown internal states from system outputs✓

Answer: Monitoring watches predefined metrics and known failure conditions, whereas observability uses logs, metrics, and traces to help teams understand and diagnose unexpected or unknown system behaviour.

In Site Reliability Engineering (SRE), what is an 'error budget'?

• AThe acceptable amount of unreliability allowed before reliability work takes priority over new features✓
• BA prioritised list of all known software defects that must be cleared before the next release can proceed
• CThe number of engineers assigned to support
• DThe financial budget allocated to fixing bugs

Answer: An error budget is the permissible level of unreliability derived from a service level objective; once it is exhausted, teams prioritise reliability work over releasing new features.