Which downtime does a provider's availability commitment typically exclude from its own measurement, and why does that matter to your contract?

## The standard carve-outs The headline figure is the part everyone quotes; the exclusion list is the part that determines what the figure means. The families are consistent across providers even where the wording differs: 1. **Announced maintenance.** Time inside a maintenance window the provider published in advance, within whatever notice period the contract states. Some services give you a choice of when the window falls; that choice is a scheduling convenience, not an exemption from the carve-out. 2. **Tenant-caused unavailability.** Downtime attributable to your configuration, your code, your credentials, or to exceeding a quota or limit you were told about. A firewall rule of yours that blocks the service is your outage, contractually. 3. **Unsupported or preview tiers.** Features in preview, trial capacity, and deployment shapes outside the committed configuration are excluded outright. 4. **Suspension under the terms.** Downtime while the account is suspended for non-payment or for an acceptable-use violation is not the provider's failure. 5. **Causes outside the provider's control.** This clause reaches further than people expect. It commonly covers the public network path between your users and the region, meaning a provider whose region is serving perfectly may be measured as fully available during an event where none of your users could reach it. ## Carve-outs move the denominator, not just the numerator A detail worth being precise about: excluded periods are normally removed from the **eligible total** as well as from the counted downtime. The measured ratio is therefore computed over a shorter window that excludes the bad parts entirely, rather than counting them as good time. The practical effect is that a heavily maintained service can post an excellent measured figure while being unavailable to users for a materially longer period than the figure implies. Nothing improper is happening; the contract is being applied as written. | Downtime your users felt | Counted against the commitment? | |---|---| | Provider incident in the region | Yes | | Announced maintenance window | Normally no — excluded from eligible time | | Your misconfigured network rule | No — tenant-caused | | A feature still in preview | No — unsupported tier | | Users' network path to the region broken | Usually no — outside provider control | | Slow but successful responses | Usually no — outside the definition of unavailable | ## Why this decides what you can promise onward This is the reason the carve-out list belongs in a design review rather than only in a procurement file. When you draft the availability commitment for your own multi-tenant reporting service, your customers measure you on the downtime they **felt**. They do not care that a period was carved out of your supplier's measurement; from their side it was an outage of your product. So the arithmetic you can honestly do is over felt downtime, and the platform's carve-outs land on your side of the line. Three practical moves follow: - **Mirror what you can.** If your suppliers exclude announced maintenance, your own commitment probably needs a maintenance-window clause too — otherwise you have absorbed a liability with no matching protection. - **Engineer around what you cannot.** Tenant-caused and preview-tier exclusions are within your control: keep production off preview features, and treat your own misconfiguration as a class of failure to be prevented rather than claimed for. - **Budget the residue.** Whatever remains — chiefly the network path to your users and the excluded maintenance you cannot pass on — is downtime you will pay for out of your own promise. Size it before you commit to a figure, not afterwards. ## How to read a commitment quickly Given a document and ten minutes, read in this order: the definition of unavailable, the exclusion list, the eligibility conditions, then the figure. Most engineers do it in reverse and form their opinion on the least informative part. An interviewer asking this question is usually checking whether you have ever actually opened one — the tell is whether you can name the tenant-caused and maintenance carve-outs without prompting, and whether you know they shrink the eligible total rather than merely failing to count.