Commitment Discounts¶
Azure gives large discounts in return for a commitment to spend. Reservations commit to a specific resource type and region. Savings plans commit to an hourly amount of compute spending. Both only save money if the committed usage really continues for one or three years.
Status: not needed yet
The estate is mostly consumption-priced PaaS: Static Web Apps, storage and Log Analytics. No steady compute exists to commit against.
Options¶
| Reservations | Savings plans for compute | Log Analytics commitment tiers | |
|---|---|---|---|
| Commit to | A resource type, SKU and region (VMs, SQL, Cosmos DB, storage capacity) | An hourly spend on compute, flexible across VM size, region and service | A daily ingestion volume |
| Discount | Highest | Slightly lower than reservations | Tiered |
| Flexibility | Low, though exchanges are possible | High | Change tier after 31 days |
| Best for | Stable, predictable workloads | Compute that changes shape but stays at a similar level | A steady ingestion volume. See Log Analytics Costs. |
When to commit¶
Commit only when all of these are true:
- The usage has been steady for at least 30 days, preferably 60. Azure Advisor's recommendations use this history.
- The workload is expected to run for the whole term. Don't commit for anything planned for retirement or redesign.
- The commitment covers the baseline, not the peak. Leave spikes on pay-as-you-go.
Process¶
- Advisor first. Azure Advisor recommends reservation and savings plan purchases from actual usage. Check it in the monthly review.
- Shared scope. Buy at a shared (billing account) scope, so the discount applies wherever matching usage occurs.
- Record every purchase: what was bought, the term, the expiry date and the owner. Set a reminder before renewal.
- Check usage monthly. An under-used reservation is money spent for nothing.