SLI and SLO Definition
What is SLI?
SLI stands for Service Level Indicator. It is a quantitative measure of a specific aspect of the service's performance. It helps teams monitor how well they are meeting the expectations of their users.
Common examples of SLIs include:
- Response time
- Availability
- Error rates
- Throughput
What is SLO?
SLO stands for Service Level Objective. It defines the target level of performance for a specific SLI. An SLO is a commitment that the service should meet over a period of time.
For example, an SLO for availability might state, "99.9% uptime over the course of a month."
Importance of SLI and SLO
SLIs and SLOs are crucial for:
- Establishing clear expectations with stakeholders.
- Improving service reliability and performance.
- Guiding prioritization of engineering work.
- Enabling effective monitoring and alerting mechanisms.
Best Practices
To effectively implement SLIs and SLOs, consider the following best practices:
- Define SLIs that are meaningful to users.
- Set realistic and achievable SLOs.
- Regularly review and adjust SLIs and SLOs based on service changes.
- Communicate SLIs and SLOs transparently with stakeholders.
FAQ
What is the difference between SLI and SLO?
SLI is a measure of service performance, while SLO is the target level set for that measure.
Can SLOs be legally binding?
Yes, SLOs can be included in service level agreements (SLAs), making them legally binding commitments.
How often should SLIs and SLOs be reviewed?
It is recommended to review SLIs and SLOs quarterly or after significant changes to the system.