Can you explain what is meant by the SLI metric in the context of system monitoring?

SLI (Service Level Indicator) is a metric that measures the quality or performance of a service from the user's perspective. For example, it could be the percentage of successful requests, response time, or system availability.

SLI helps understand how well the service meets expectations and requirements, and serves as the basis for defining SLO (Service Level Objective) — target values for these metrics.

Example: if SLI is the API response time, then you can measure what percentage of requests are processed faster than 200 ms. If this percentage is below the set SLO, it means the service is not performing at the required level.