Kener Documentation

Maintenance events are the individual occurrences of a maintenance window. This guide explains how events are generated, their lifecycle, and how they transition between states.

What is a Maintenance Event?

A maintenance event represents a single occurrence of a maintenance window. Each event has:

Start Date/Time - When this occurrence begins
End Date/Time - When this occurrence ends (start + duration)
Status - Current state (SCHEDULED, READY, ONGOING, COMPLETED, CANCELLED)
Maintenance ID - Links back to the parent maintenance

Relationship:

Maintenance (1) → Events (many)
"Weekly Updates" → [Event 1, Event 2, Event 3, ...]

Automatic Event Generation

Events are created automatically by Kener based on the maintenance type and schedule.

One-Time Maintenances

When: Event created immediately when maintenance is created

How Many: Exactly 1 event

Example:

Maintenance: Database Migration
RRULE: FREQ=MINUTELY;COUNT=1
Start: May 15, 2026 at 2:00 AM
Duration: 3 hours

Generated Event:
- Start: May 15, 2026 at 2:00 AM
- End: May 15, 2026 at 5:00 AM
- Status: SCHEDULED

Recurring Maintenances

When:

Initial events created when maintenance is created
New events generated every hour by scheduler

How Many: Events for the next 7 days

Example:

Maintenance: Weekly Security Updates
RRULE: FREQ=WEEKLY;BYDAY=SU
Start: May 15, 2026 at 3:00 AM
Duration: 1 hour

Generated Events (assuming today is May 10):
1. May 15, 3:00 AM - 4:00 AM (SCHEDULED)
2. May 22, 3:00 AM - 4:00 AM (SCHEDULED)
3. May 29, 3:00 AM - 4:00 AM (SCHEDULED)
4. June 5, 3:00 AM - 4:00 AM (SCHEDULED)

Rolling Window:
The scheduler runs every hour and ensures there are always events for the next 7 days:

Today is May 15 → Events through May 22 exist
Tomorrow (May 16) → Scheduler creates event for May 23
Continuous 7-day lookahead

Duplicate Prevention

The system prevents duplicate events:

Check if event for specific start time already exists
Skip creation if duplicate found
Only create missing events

This ensures the hourly scheduler doesn't create duplicates.

Event Lifecycle States

Every maintenance event progresses through a series of states that track its progress.

State Diagram

SCHEDULED → READY → ONGOING → COMPLETED
    ↓          ↓        ↓
  [CANCELLED at any point]

State Descriptions

SCHEDULED

When: Event created, more than 60 minutes until start time

Meaning:

Maintenance is scheduled but not imminent
Visible to users in upcoming maintenances
No notifications sent yet

Displayed As: "Scheduled" or "In X hours/days"

Example:

Current Time: May 15, 12:00 PM
Event Start: May 15, 3:00 PM
Status: SCHEDULED (3 hours away)

READY

When: Current time is within 60 minutes of start time

Meaning:

Maintenance starting soon
Advance notification sent to subscribers
Monitor status not yet overridden

Displayed As: "Starting soon" or "In X minutes"

Notification: "Maintenance Starting Soon" notification sent

Example:

Current Time: May 15, 2:15 PM
Event Start: May 15, 3:00 PM
Status: READY (45 minutes away)
Action: Send notification

Automatic Transition:

SCHEDULED → READY
Condition: (current_time + 60 minutes) >= start_time
Executed by: Status update scheduler (runs every minute)

ONGOING

When: Current time is between start time and end time

Meaning:

Maintenance is actively happening
Monitor statuses overridden to configured impact levels
Shown prominently on status page

Displayed As: "Ongoing" or "In progress"

Notification: "Maintenance In Progress" notification sent

Example:

Current Time: May 15, 3:30 PM
Event Start: May 15, 3:00 PM
Event End: May 15, 4:00 PM
Status: ONGOING (30 minutes in, 30 minutes remaining)
Action: Override monitor statuses

Automatic Transition:

READY → ONGOING
title: Maintenance Events
description: How maintenance events are generated and shown to users

A maintenance event is one occurrence of a maintenance window.

Event generation

One-time maintenance

Creates one event.
Triggered when maintenance is created.
Monitor statuses restored to realtime values

Recurring maintenance

Creates upcoming events from RRULE.
Scheduler refreshes upcoming occurrences.
Duplicate event start times are skipped.

Event statuses

SCHEDULED
READY
ONGOING
COMPLETED
CANCELLED

Status transitions are time-based and automatic.
Current Time: May 15, 4:05 PM

User-visible behavior

Status: COMPLETED (finished 5 minutes ago)

Ongoing events affect monitor display according to impact settings.
Upcoming and past visibility depends on site/page event display settings.

## Manual actions {#manual-actions}
**Automatic Transition:**
- You can cancel/delete events from maintenance management screens.
- Edit the parent maintenance to regenerate future schedule behavior.

Condition: current_time >= end_time

Creating and Managing Maintenances
Impact on Monitoring
RRULE Patterns
Displayed As: "Cancelled"

Notification: No automatic notification

Manual Action: User clicks delete/cancel on event

Automatic Status Transitions

Kener runs a scheduler every minute that updates event statuses based on the current time.

Transition Logic

SCHEDULED → READY:

// Find events where:
status === 'SCHEDULED' AND
start_date_time > current_time AND
start_date_time <= (current_time + 3600) // 60 minutes in seconds

// Update to READY
// Send "starting soon" notification

READY → ONGOING:

// Find events where:
status === 'READY' AND
start_date_time <= current_time AND
end_date_time >= current_time

// Update to ONGOING
// Send "in progress" notification
// Override monitor statuses

ONGOING → COMPLETED:

// Find events where:
status === 'ONGOING' AND
end_date_time < current_time

// Update to COMPLETED
// Send "completed" notification
// Restore monitor statuses

Scheduler Details

Frequency: Every minute

Purpose:

Update event statuses based on time
Send appropriate notifications
Trigger monitor status overrides/restores

Implementation:
Runs as part of UpdateMaintenanceEventStatuses() in maintenance controller

Event Notifications

Notifications are triggered during state transitions:

Notification Types

Starting Soon (SCHEDULED → READY):

Subject: Maintenance Starting Soon
Body: "{title} is starting in {time_until_start}"
Monitors: List of affected monitors with impacts
When: 60 minutes before start

In Progress (READY → ONGOING):

Subject: Maintenance In Progress
Body: "{title} is now in progress"
Monitors: List of affected monitors with impacts
When: At start time

Completed (ONGOING → COMPLETED):

Subject: Maintenance Completed
Body: "{title} has been completed"
Monitors: List of affected monitors with impacts
When: At end time

Notification Channels

Notifications are sent based on your subscription configuration:

Email (if enabled)
Webhooks (if configured)
Slack (if configured)
Discord (if configured)

Only users subscribed to maintenance updates receive notifications.

Viewing Events

Dashboard View

On the maintenance edit page:

Scroll to Maintenance Events section
Events listed in chronological order
Current/next event highlighted
Shows status, dates, and duration

Event Display:

┌─────────────────────────────────────┐
│ [SCHEDULED] Scheduled               │
│ May 22, 2026 03:00 → 04:00          │
│ Duration: 1h                        │
├─────────────────────────────────────┤
│ [ONGOING] Ongoing (Current)         │
│ May 15, 2026 03:00 → 04:00          │
│ Duration: 1h                        │
├─────────────────────────────────────┤
│ [COMPLETED] Completed               │
│ May 8, 2026 03:00 → 04:00           │
│ Duration: 1h                        │
└─────────────────────────────────────┘

Status Page View

Users see events on the public status page:

Ongoing Maintenances:

Prominently displayed on home page
Affected monitors show MAINTENANCE status
Progress/countdown indicator

Upcoming Maintenances:

Listed in separate section
Shows start time and affected services
Countdown to start

Past Maintenances:

Events/history page
Filterable by date range
Shows completed events

Managing Events Manually

Cancelling Events

From the maintenance edit page:

Find the event in the list
Click the trash icon
Confirm cancellation
Event status changes to CANCELLED

When to Cancel:

Maintenance no longer needed
Rescheduling to different time
Discovered conflict

Note: Cancelled events remain in history but are not executed.

Deleting Events

Events can be permanently deleted:

Click trash icon on event
Confirm deletion
Event removed from database

Warning: Deletion is permanent and cannot be undone.

When to Delete:

Cleaning up old historical events
Removing erroneous events
Database maintenance

Best Practice: Cancel rather than delete to preserve history.

Cannot Edit Events

Individual events cannot be edited directly. To change event timing or duration:

Edit the parent maintenance
Update start time, RRULE, or duration
Save maintenance

Result:

Future SCHEDULED events deleted
New events generated with updated settings
ONGOING/COMPLETED events preserved

Event Retention

Events are retained indefinitely by default:

SCHEDULED Events:

Kept until executed or cancelled
Automatically progress through lifecycle

COMPLETED Events:

Kept as historical records
Visible on status page based on page settings

CANCELLED Events:

Kept as historical records
Marked explicitly as cancelled

Deletion:

Events deleted when parent maintenance is deleted
Can be manually deleted via dashboard
No automatic cleanup (configure if needed)

Events and Monitor Status

During ONGOING events:

Monitor status overridden to configured impact
Realtime monitoring continues in background
Status page shows maintenance impact

See Maintenance Impact on Monitoring for details.

Troubleshooting

Problem: Events not transitioning to READY/ONGOING

Solutions:

Check scheduler is running (npm start in production)
Verify system clock is accurate
Check logs for scheduler errors

Problem: No events generated for recurring maintenance

Solutions:

Verify maintenance status is ACTIVE
Check RRULE is valid
Wait for hourly scheduler to run
Check start_date_time is not too far in future

Problem: Events not visible on status page

Solutions:

Check page settings for visibility window
Verify events are within configured date range
Ensure affected monitors are not hidden

Problem: Too many events generated

Solutions:

For one-time: Check RRULE contains COUNT=1
For recurring: Events for next 7 days is expected
Old events can be manually deleted

Next Steps

Maintenance Impact on Monitoring - How events affect monitor status display
RRULE Patterns - Advanced scheduling patterns for recurring maintenances
Creating and Managing Maintenances - Learn how to create and edit maintenances

Maintenance Events

What is a Maintenance Event?

Automatic Event Generation

One-Time Maintenances

Recurring Maintenances

Duplicate Prevention

Event Lifecycle States

State Diagram

State Descriptions

SCHEDULED

READY

ONGOING

Event generation

One-time maintenance

Recurring maintenance

Event statuses

User-visible behavior

Related guides

Automatic Status Transitions

Transition Logic

Scheduler Details

Event Notifications

Notification Types

Notification Channels

Viewing Events

Dashboard View

Status Page View

Managing Events Manually

Cancelling Events

Deleting Events

Cannot Edit Events

Event Retention

Events and Monitor Status

Troubleshooting

Next Steps