SLA, SLO, and SLI definitions in HLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does SLA stand for and what is its purpose?

SLA stands for Service Level Agreement. It is a formal contract between a service provider and a customer that defines the expected level of service, including specific performance and availability targets.

beginner

Define SLO in the context of service management.

SLO stands for Service Level Objective. It is a specific measurable goal within an SLA that defines the target level of service performance, such as 99.9% uptime.

beginner

What is an SLI and how is it used?

SLI stands for Service Level Indicator. It is a metric that measures the actual performance of a service, such as latency or error rate, used to determine if SLOs are being met.

intermediate

How do SLA, SLO, and SLI relate to each other?

An SLA is the overall agreement that includes one or more SLOs, which are specific targets. SLIs are the metrics used to measure if those SLOs are achieved, helping to monitor the SLA compliance.

intermediate

Why is it important to have clear SLIs in a service agreement?

Clear SLIs provide objective data to track service performance. They help both providers and customers understand if the service meets agreed targets, enabling trust and informed decisions.

What does SLO specifically define in a service agreement?

A The measurable target for service performance

B The overall contract between provider and customer

C The metric used to measure service quality

D The penalty for service failure

SLO defines the measurable target or goal for service performance within an SLA.

Which term refers to the actual metric used to measure service performance?

A SLO

B SLI

C SLA

D SLC

SLI is the metric that measures actual service performance.

What is the main purpose of an SLA?

A To define the technical architecture

B To write code for the service

C To monitor daily system logs

D To set formal service expectations between provider and customer

An SLA sets formal expectations and agreements on service levels.

If a service has an SLO of 99.9% uptime, what does this mean?

A The service is free for 99.9% of users

B The service will fail 99.9% of the time

C The service must be available 99.9% of the time

D The service has 99.9% error rate

An SLO of 99.9% uptime means the service should be available 99.9% of the time.

Which of the following is NOT part of SLA, SLO, and SLI definitions?

A Service Level Implementation

B Service Level Objective

C Service Level Indicator

D Service Level Agreement

Service Level Implementation is not a standard term; SLA, SLO, and SLI are the correct terms.

Explain the differences and relationships between SLA, SLO, and SLI in simple terms.

Think of SLA as the contract, SLO as the goals, and SLI as the measurements.

Why is it important for a service provider to monitor SLIs regularly?

Monitoring SLIs helps check if the service is doing what it promised.