SLOs

Getting Started

Service level objectives become the common language for cross-functional teams to set guardrails and incentives to drive high levels of service reliability. Within the SLO, SLIs are a quantitative measure, typically provided through your APM platform. Traditionally, these refer to either latency or availability and are points on a digital user journey that contribute to customer experience and satisfaction.

Service Level Indicators

A Service Level Indicator (SLI) is “a carefully defined quantitative measure of some aspect of the level of service that is provided.”

SLIs are a quantitative measure, typically provided through your APM platform. Traditionally, these refer to either latency or availability, which are defined as response times, including queue/wait time, in milliseconds. A collection of SLIs, or composite SLIs, are a group of SLIs attributed to a larger SLO. These indicators are points on a digital user journey that contribute to customer experience and satisfaction.

Once you have SLIs set up, you connect them to your SLOs, which are targets against your SLI.

Service Level Objectives

A Service Level Objective (SLO) is “a target value or range of values for a service level that is measured by an SLI. A natural structure for SLOs is thus SLI ≤ target, or lower bound ≤ SLI ≤ upper bound.

Service level objectives become the common language for cross-functional teams to set guardrails and incentives to drive high levels of service reliability.

SLOs give you the objective language and measure of how to prioritize reliability work for proactive service health.

Service Level Agreements

A Service Level Agreement is “an explicit or implicit contract with your users that includes consequences of meeting (or missing) the SLOs they contain.”

Service level agreements are set by the business rather than engineers, SREs, or ops. When anything happens to an SLO, typically your SLA will kick in; they're the actions that are taken when your SLO fails and often result in financial or contractual consequences.

Refer to the Google SRE Handbook for more information.

For instructions regarding the creation, configuraton, and use of SLOs and SLIs, refer to the SLO Guide.