Definition: What Is a Service Level Indicator?
A Service Level Indicator (SLI) is a quantitative measure that provides insight into a specific aspect of the performance of a system or service. SLIs are used to establish a baseline for the performance of a system or service and are typically used in conjunction with Service Level Objectives (SLOs) to set specific performance goals.
SLIs can measure various aspects of service performance, such as availability, reliability, responsiveness, and throughput. For example, an SLI for a web application might measure the average response time for a specific request, such as loading a page or processing a transaction. An SLI for a database might measure the average query time or the percentage of successful transactions.
SLIs are a key component of Service Level Agreements (SLAs) because they provide specific metrics for measuring the performance of a system or service against the agreed-upon service levels. SLAs establish the overall terms and conditions of the service agreement, while SLIs provide the specific quantitative measures used to track and report on the system or service’s performance. SLIs are critical to ensuring that service providers are meeting their obligations under the SLA and delivering high-quality service to their customers.