What is a maintenance window?
A maintenance window is a pre-scheduled period of planned work that you want to communicate to users in advance. Unlike incidents (which are unplanned), maintenance windows let you:
- Warn users before work begins
- Suppress unexpected-outage alerts during the maintenance period
- Show a clear “Under Maintenance” status on the public page while work is in progress
- Automatically mark the window as complete when it ends
Maintenance structure
A maintenance record in Kener has two levels:
- Maintenance — the template. Defines the title, description, schedule (RRULE + start time + duration), which monitors are affected, and whether it is active.
- Maintenance events — the concrete occurrences generated from the maintenance template. Each event has its own
start_date_time, end_date_time, and status.
This separation supports both one-time and recurring maintenance without duplicating data.
Maintenance event states
Each maintenance event (occurrence) has one of the following statuses:
| Status | Meaning |
|---|
SCHEDULED | The event is more than 60 minutes in the future. |
READY | The event starts within the next 60 minutes. Reminder notifications are sent at this transition. |
ONGOING | The current time is within the event’s start/end window. The affected monitors show the maintenance status on the public page. |
COMPLETED | The event’s end_date_time has passed. Kener marks it complete automatically. |
CANCELLED | The event was manually cancelled. |
The 60-minute reminder buffer is configurable via the global maintenance notification settings (reminder_buffer_hours). It controls when an event transitions from SCHEDULED to READY.
| Status | Meaning |
|---|
ACTIVE | The maintenance is enabled and events will be generated. |
INACTIVE | The maintenance is disabled. No new events will be generated. |
Creating a maintenance window
Go to Manage → Maintenances → New Maintenance.
Required fields
| Field | Description |
|---|
| Title | Short description of the work being done. Required. |
| Start date/time | The date and time of the first (or only) occurrence. Stored as a Unix timestamp (UTC). Required. |
| Duration | How long each window lasts, in seconds. Must be greater than 0. Required. |
| RRULE | An iCalendar RRULE string that defines the recurrence pattern. Required. |
Optional fields
| Field | Description |
|---|
| Description | Longer explanation of what the maintenance involves. Shown on the public status page. |
| Affected monitors | Monitors whose displayed status should change during the window, with their impact level. |
| Global maintenance | When YES (default), the window appears on all status pages. |
One-time vs. recurring maintenance
Whether a maintenance window is one-time or recurring is determined entirely by the RRULE.
A one-time maintenance uses FREQ=MINUTELY;COUNT=1 (or any rule with COUNT=1). Kener detects COUNT=1 and treats it as a single occurrence.The event is created immediately at the start_date_time you provide. No further events are generated.One-time maintenance events that are already more than 24 hours in the past at creation time are not generated. Plan accordingly when back-dating.
Any RRULE without COUNT=1 defines a recurring schedule. For example:This schedules the window every Sunday at the time defined by start_date_time.Other examples:FREQ=DAILY
FREQ=MONTHLY;BYDAY=1MO
FREQ=WEEKLY;BYDAY=MO,WE,FR
How affected monitors are displayed
When you attach a monitor to a maintenance window, you choose its impact level during the maintenance:
| Impact | Display on status page |
|---|
UP | Monitor shows as operational |
DOWN | Monitor shows as down |
DEGRADED | Monitor shows as degraded |
MAINTENANCE | Monitor shows as under maintenance (default) |
ONGOING event, Kener uses these overrides instead of the monitor’s live check results. Once the event is COMPLETED, the monitor returns to its live status.
Automatic event generation
Kener’s maintenance scheduler runs every hour and pre-generates recurring maintenance events for the next 7 days. This ensures that upcoming events exist in the database in time for reminder notifications.
For one-time maintenances (COUNT=1), events are created at the time the maintenance is saved and are not re-generated by the scheduler.
If you create a recurring maintenance and do not see an upcoming event immediately, wait up to one hour for the scheduler to run, or check back after a page refresh.
Notifications
Kener sends subscriber notifications at key lifecycle transitions for each maintenance event:
| Transition | Notification type |
|---|
| Event created | created |
Event transitions to READY (within reminder buffer) | starting_soon — includes time until start |
Event transitions to ONGOING | ongoing |
Event transitions to COMPLETED | completed |
event_types configuration).
Editing a maintenance
To edit an existing maintenance:
- Open it from Manage → Maintenances
- Modify the title, description, schedule, or monitors
- Save
When the schedule changes (start time, RRULE, or duration), Kener handles existing events:
- One-time maintenance: all non-
COMPLETED and non-CANCELLED events are deleted and a new event is generated from the updated schedule.
- Recurring maintenance: only future
SCHEDULED events are deleted and regenerated. Events already ONGOING, COMPLETED, or CANCELLED are preserved.
Deleting a maintenance
Deleting a maintenance permanently removes the maintenance record and all of its associated events and monitor links (via cascade delete).
How maintenance appears on the public status page
During an ONGOING maintenance event:
- Affected monitors display their configured impact level (default:
MAINTENANCE)
- If the overall page status is driven by monitors all showing
MAINTENANCE, the page banner shows “Under Maintenance”
- The maintenance window (title and description) is listed in the maintenance section of the status page for its duration
Past COMPLETED events remain visible in the historical view for transparency.
Filtering the maintenance list
The Manage → Maintenances list defaults to showing ACTIVE maintenances. Use the status filter to switch between:
- Active — maintenances that are enabled and will generate future events
- Inactive — disabled maintenances
- All — both active and inactive
The list shows 10 items per page. Each row displays the maintenance type (One-Time or Recurring), duration, number of affected monitors, and the next upcoming event with its status.