
About
Framework for defining and implementing Service Level Indicators (SLIs), Service Level Objectives (SLOs), and error budgets.
name: slo-implementation description: "Framework for defining and implementing Service Level Indicators (SLIs), Service Level Objectives (SLOs), and error budgets." risk: unknown source: community date_added: "2026-02-27"
SLO Implementation
Framework for defining and implementing Service Level Indicators (SLIs), Service Level Objectives (SLOs), and error budgets.
Do not use this skill when
- The task is unrelated to slo implementation
- You need a different domain or tool outside this scope
Instructions
- Clarify goals, constraints, and required inputs.
- Apply relevant best practices and validate outcomes.
- Provide actionable steps and verification.
- If detailed examples are required, open
resources/implementation-playbook.md.
Purpose
Implement measurable reliability targets using SLIs, SLOs, and error budgets to balance reliability with innovation velocity.
Use this skill when
- Define service reliability targets
- Measure user-perceived reliability
- Implement error budgets
- Create SLO-based alerts
- Track reliability goals
SLI/SLO/SLA Hierarchy
SLA (Service Level Agreement)
↓ Contract with customers
SLO (Service Level Objective)
↓ Internal reliability target
SLI (Service Level Indicator)
↓ Actual measurement
Defining SLIs
Common SLI Types
1. Availability SLI
# Successful requests / Total requests
sum(rate(http_requests_total{status!~"5.."}[28d]))
/
sum(rate(http_requests_total[28d]))
2. Latency SLI
# Requests below latency threshold / Total requests
sum(rate(http_request_duration_seconds_bucket{le="0.5"}[28d]))
/
sum(rate(http_request_duration_seconds_count[28d]))
3. Durability SLI
# Successful writes / Total writes
sum(storage_writes_successful_total)
/
sum(storage_writes_total)
Reference: See references/slo-definitions.md
Setting SLO Targets
Availability SLO Examples
| SLO % | Downtime/Month | Downtime/Year | |-------|----------------|---------------| | 99% | 7.2 hours | 3.65 days | | 99.9% | 43.2 minutes | 8.76 hours | | 99.95%| 21.6 minutes | 4.38 hours | | 99.99%| 4.32 minutes | 52.56 minutes |
Choose Appropriate SLOs
Consider:
- User expectations
- Business requirements
- Current performance
- Cost of reliability
- Competitor benchmarks
Example SLOs:
slos:
- name: api_availability
target: 99.9
window: 28d
sli: |
sum(rate(http_requests_total{status!~"5.."}[28d]))
/
sum(rate(http_requests_total[28d]))
- name: api_latency_p95
target: 99
window: 28d
sli: |
sum(rate(http_request_duration_seconds_bucket{le="0.5"}[28d]))
/
sum(rate(http_request_duration_seconds_count[28d]))
Error Budget Calculation
Error Budget Formula
Error Budget = 1 - SLO Target
Example:
- SLO: 99.9% availability
- Error Budget: 0.1% = 43.2 minutes/month
- Current Error: 0.05% = 21.6 minutes/month
- Remaining Budget: 50%
Error Budget Policy
error_budget_policy:
- remaining_budget: 100%
action: Normal development velocity
- remaining_budget: 50%
action: Consider postponing risky changes
- remaining_budget: 10%
action: Freeze non-critical changes
- remaining_budget: 0%
action: Feature freeze, focus on reliability
Reference: See references/error-budget.md
SLO Implementation
Prometheus Recording Rules
# SLI Recording Rules
groups:
- name: sli_rules
interval: 30s
rules:
# Availability SLI
- record: sli:http_availability:ratio
expr: |
sum(rate(http_requests_total{status!~"5.."}[28d]))
/
sum(rate(http_requests_total[28d]))
# Latency SLI (requests < 500ms)
- record: sli:http_latency:ratio
expr: |
sum(rate(http_request_duration_seconds_bucket{le="0.5"}[28d]))
/
sum(rate(http_request_duration_seconds_count[28d]))
- name: slo_rules
interval: 5m
rules:
# SLO compliance (1 = meeting SLO, 0 = violating)
- record: slo:http_availability:compliance
expr: sli:http_availability:ratio >= bool 0.999
- record: slo:http_latency:compliance
expr: sli:http_latency:ratio >= bool 0.99
# Error budget remaining (percentage)
- record: slo:http_availability:error_budget_remaining
expr: |
(sli:http_availability:ratio - 0.999) / (1 - 0.999) * 100
# Error budget burn rate
- record: slo:http_availability:burn_rate_5m
expr: |
(1 - (
sum(rate(http_requests_total{status!~"5.."}[5m]))
/
sum(rate(http_requests_total[5m]))
)) / (1 - 0.999)
SLO Alerting Rules
groups:
- name: slo_alerts
interval: 1m
rules:
# Fast burn: 14.4x rate, 1 hour window
# Consumes 2% error budget in 1 hour
- alert: SLOErrorBudgetBurnFast
expr: |
Compatible Tools
Claude CodeCursor
Tags
DevOps

