TechAni

Advanced SLO CalculatorComposite mode

Enterprise-grade SLO planning with availability or latency SLIs, evaluation periods, baseline adjustment, and recommended multi-window burn alerts.

LowMediumHighCritical

Selected: high

What is an SLO?

A Service Level Objective (SLO) is a target reliability level for a service, measured via SLIs like availability or latency. The error budget is the permissible failure within a period given your SLO.

Choose SLOs that balance user expectations with on-call sustainability and engineering cost.

Composite SLO
99.96%
Error budget (events)
400
Error budget %
0.040%
Allowed downtime (min/period)
17.28
Downtime (hrs/yr)
3.50
On-call burden
Medium

Error Budget Over Time

Cumulative allowed budget (upper bound) across the selected period and the constant daily allowance.

Recommended Multi‑Window Burn Alerts

Use fast + slow windows to catch both sharp regressions and smoldering issues.

Window (hrs)Burn rateBudget consumed
114.4×0%
66×0%
243×0%
721×0%

Per‑endpoint Split

Allocate error budget between critical and non‑critical endpoints.

Critical endpoints (60%)
240 events
Non‑critical endpoints (40%)
160 events

Exports

How to use this calculator

Quick start

  • Choose an evaluation period that matches how you operate (7/30/90/365 days).
  • Enter total events in period (requests/transactions).
  • Set business criticality and optional baseline good ratio (historical success).
  • Toggle Composite mode to combine availability + latency; tune method and weights.

Composite mode

  • Uses both availability and latency. The “SLI type” control is disabled while composite is on.
  • Min method takes the stricter of the two SLOs; Weighted averages by your weights.
  • Latency settings (threshold & percentile) are always active in composite.

Inputs

  • Service type adjusts recommended SLO bands and on‑call burden.
  • Existing uptime seeds target realism; baseline good ratio nudges the recommendation.
  • Latency: set a user‑meaningful threshold (e.g., 200ms) and percentile (p95/p99).
  • Per‑endpoint split allocates error budget between critical and non‑critical endpoints.

Outputs & alerts

  • Recommended SLO / Composite SLO and error budget (events & %).
  • Allowed downtime for the selected period and estimated on‑call burden.
  • Chart: cumulative allowed budget and steady daily allowance.
  • Burn alerts: multi‑window pairs catch both spikes (1h) and slow burns (24–72h).
  • Exports: JSON (inputs + results), CSV (alert table), YAML (Alertmanager rules).

Why this is helpful

  • Right‑sized targets that balance user expectations with sustainable on‑call.
  • Faster alerting setup with opinionated, production‑tested burn‑rate windows.
  • Decision support via baseline adjustment, composite SLIs, and per‑endpoint budgeting.