Glossary
Maintenance window
A maintenance window is a planned period of work on a service, announced in advance, during which disruption is expected and alerts are usually paused.
Also called Scheduled maintenance, Planned downtime.
A maintenance window is a planned period of work on a service, announced ahead of time. It is also called scheduled maintenance or planned downtime. The difference from an outage is one of expectation: the same ten minutes of unavailability is a maintenance window if customers were told in advance, and an incident if they were not. That is why the announcement is the substance of the practice, not the paperwork around it.
Maintenance windows also matter in contracts. Many SLAs leave announced maintenance out of the availability figure, but only if it was announced within the notice period the contract sets, and sometimes only at agreed times of day or a limited number of times a month. Skipping the announcement does not just surprise customers. It turns planned work into downtime that counts against the SLA.
Alerts are normally paused during the window, and that is where the risk sits. The pause should cover only the monitors the work affects and end at a fixed time. A pause that is broader or longer than the work hides a real failure the work itself caused, and that is the most likely moment for one. There are two ways to pause. Stopping the checks keeps planned failures out of the record. Keeping the checks running and silencing only the alerts means the record shows exactly when the service came back, including a window that overran.
A few habits make a window go smoothly. Announce it on the status page and to subscribers, with a start time, an end time and the services affected. Schedule it when traffic is lowest for the customers it affects. Post an update when the work starts and again when it ends. If it is going to run past its end time, say so publicly before it does, not after.
| Question | Maintenance window | Outage |
|---|---|---|
| Planned in advance? | Yes, with a start and an end time | No |
| Are customers told? | Yes, before it starts | Only once it is noticed |
| Does it count against the SLA? | Usually not, if announced within the notice period | Yes |
| Do alerts fire? | Usually paused for the services the work affects | Yes, and someone is paged |
| How does the status page show it? | As scheduled maintenance | As an incident |
| Who decides when it ends? | The team, in advance | Whoever finds and fixes the fault |
Questions
What is a maintenance window?
A maintenance window is a planned period, announced in advance, when a team works on a service and some disruption is expected. It is also called scheduled maintenance or planned downtime. Announcing it before it starts is what separates it from an outage.
What is the difference between a maintenance window and an outage?
Expectation. A maintenance window is planned and announced before it starts, with an end time. An outage is unplanned, and customers find out when something breaks. The same ten minutes of downtime can be either, depending on whether anyone was told in advance.
Does a maintenance window count against an SLA?
Usually not, if it was announced properly. Many SLAs leave scheduled maintenance out of the availability figure, as long as customers got the notice the contract requires. Maintenance that was not announced in time is normally counted as downtime. Check the exact terms of your own contract.
Should monitoring be paused during a maintenance window?
Pause the alerts for the services the work affects, and end the pause at a fixed time. Whether the checks keep running is a choice. Stopping them keeps planned failures out of the record. Keeping them running shows exactly when the service came back, which is how you notice a window that overran.
How far in advance should maintenance be announced?
At least as far ahead as any contract requires, and far enough for customers to plan around it. For routine work a few days is usually enough; give larger changes a week or more. Send a reminder shortly before it starts, and an update when it ends.
In Uptimely
Uptimely has scheduled maintenance as its own object. Attach monitors to it, and while it is ongoing those monitors are not checked, so their checks cannot declare an incident. Checks resume when it ends, unless another ongoing window still covers the monitor. It can also set the attached monitors to a status you choose when it starts. It appears on the status pages it is attached to, and status-page subscribers can be notified when it is created, before it starts, when it starts and when it ends. For a short deploy there is also a per-monitor mute with an expiry: checks keep running and the status keeps updating, but no new incidents or alerts are declared until it expires.
Uptimely lets you schedule maintenance, show it on your status page and notify subscribers, and stops checking the monitors it covers until it ends.
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Part of the Uptimely monitoring glossary — plain definitions of the vocabulary uptime monitoring, incident response and status pages are discussed in. Something here read wrong to you? Email support@getuptimely.com.