Service-Level Objectives

A Foundational Framework for Business Reliability

Master the art of balancing innovation with reliability through data-driven SLOs, error budgets, and strategic service management.

99.9%
Typical SLO Target
43.2 min
Monthly Error Budget
4
Golden Signals

Understanding SLIs, SLOs, and SLAs

These three foundational concepts form the reliability framework. Click on each concept to learn more.

Service-Level Indicator (SLI)

Quantitative measures of service performance

What it measures:

  • Availability: Proportion of successful requests
  • Latency: Response time in milliseconds
  • Throughput: Requests per second
  • Error Rate: Failed requests percentage
Example: "95% of requests complete in under 200ms"

Service-Level Objective (SLO)

Internal targets for service performance

Key characteristics:

  • Internal performance targets
  • Based on user needs and business goals
  • Realistic and achievable
  • Triggers internal responses when breached
Example: "99.9% availability over 30 days"

Service-Level Agreement (SLA)

Legal contracts with customers

Key characteristics:

  • Legal contract with customers
  • Financial penalties for violations
  • External-facing commitments
  • Usually less strict than internal SLOs
Example: "99.5% uptime with service credits for violations"

Quick Comparison

Concept Purpose Audience Consequences
SLI Measure performance Engineering teams None
SLO Set internal targets Internal teams Triggers internal actions
SLA Legal commitments External customers Financial penalties

SLO & Error Budget Calculator

Calculate the real-world implications of your SLO targets and understand your error budget.

Configure Your SLO

Results

0.1%
Error Budget
43.2 min
Allowed Downtime
719.6 hrs
Required Uptime

Error Budget Visualization

Used: 0% Remaining: 100%

SLO Target Comparison

Real-World Case Studies

Explore how different companies would approach SLOs based on their business models.

Spotify: The Experience Engine

Seamless, personalized music streaming experience

Critical User Journeys

Music Discovery

Personalized playlists and recommendations

Streaming

Uninterrupted music and podcast playback

Account Management

Profile access and subscription management

Likely SLOs

Availability: 99.9% for streaming services
Latency: P99 < 200ms for recommendations
Throughput: Handle peak concurrent users

Uber: Reliability as a Mission

"Transportation as reliable as running water, everywhere, for everyone"

Mission-Critical Services

Ride Matching

Connect riders with drivers instantly

Payment Processing

Secure and reliable transactions

Real-time Tracking

Live location and ETA updates

Likely SLOs

Availability: 99.99% for ride requests
Latency: < 100ms for matching system
Data Integrity: 99.999% for transactions

Etsy: The Trust-Based Marketplace

Secure marketplace for individual sellers and buyers

Trust-Critical Functions

Product Search

Accurate and relevant search results

Checkout Process

Secure and reliable transactions

Security

Protect seller and buyer data

Likely SLOs

Availability: 99.5% for core services
Latency: P95 < 500ms for search
Correctness: 99.9% for transactions

Error Budget Policy Simulator

Simulate how different incidents and policies affect your error budget.

Simulate Incidents

Error Budget Policy

Simulation Results

Month Progress Day 1
Budget Healthy
Continue normal operations

Recommended Actions

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