Storage Alert System

The storage alert system monitors per-destination storage usage and sends notifications when configurable thresholds are crossed. It runs automatically after every storage statistics refresh cycle.

Location: src/services/storage/storage-alert-service.ts

Alert Types

Three independent alert types can be enabled per storage destination:

Usage Spike

Compares the two most recent storage snapshots. Sends an alert if the size changed by more than usageSpikeThresholdPercent percent in either direction.

Requires at least two snapshots — no alert fires on the first measurement.

Notification event: STORAGE_USAGE_SPIKE

Storage Limit

Triggers when storage usage reaches or exceeds 90% of the configured storageLimitBytes. The 90% threshold is hard-coded; the configurable value is the upper limit in bytes.

Notification event: STORAGE_LIMIT_WARNING

Missing Backup

Checks how long ago the backup count in storage last increased. If no new backup has appeared in missingBackupHours hours, an alert fires. Uses up to the last 100 snapshots as history.

Notification event: STORAGE_MISSING_BACKUP

Configuration

Alert configuration is stored per-destination in the SystemSetting table under the key storage.alerts.<configId>. Retrieve and save it with:

import { getAlertConfig, saveAlertConfig } from "@/services/storage/storage-alert-service";

const config = await getAlertConfig(configId);
await saveAlertConfig(configId, {
  usageSpikeEnabled: true,
  usageSpikeThresholdPercent: 50,       // alert on ≥50% size change
  storageLimitEnabled: true,
  storageLimitBytes: 10 * 1024 ** 3,    // 10 GB limit
  missingBackupEnabled: false,
  missingBackupHours: 48,               // alert if no backup in 48 h
});

StorageAlertConfig interface

export interface StorageAlertConfig {
  usageSpikeEnabled: boolean;
  usageSpikeThresholdPercent: number;  // e.g. 50 = 50%

  storageLimitEnabled: boolean;
  storageLimitBytes: number;           // bytes

  missingBackupEnabled: boolean;
  missingBackupHours: number;
}

Defaults (for destinations with no saved config):

Field	Default
usageSpikeEnabled	false
usageSpikeThresholdPercent	50
storageLimitEnabled	false
storageLimitBytes	10737418240 (10 GB)
missingBackupEnabled	false
missingBackupHours	48

State Tracking

The service tracks the active/inactive state of each alert type separately to prevent notification flooding:

export interface AlertTypeState {
  active: boolean;             // whether the condition is currently active
  lastNotifiedAt: string | null;  // ISO timestamp of last notification sent
}

export interface StorageAlertStates {
  usageSpike: AlertTypeState;
  storageLimit: AlertTypeState;
  missingBackup: AlertTypeState;
}

State is persisted per-destination in SystemSetting under the key storage.alerts.<configId>.state.

Notification Lifecycle

Transition	Behavior
Inactive - Active	Notification sent immediately
Active - Active (cooldown not elapsed)	No notification
Active - Active (cooldown elapsed)	Reminder notification sent
Active - Inactive	State reset; next occurrence fires immediately

Default cooldown: 24 hours (ALERT_COOLDOWN_MS = 24 * 60 * 60 * 1000).

The cooldown can be overridden per notification event via the reminder interval setting in Settings - Notifications. Setting the interval to 0 disables reminders (only the first occurrence fires).

Trigger Point

checkStorageAlerts(entries) is called by the storage service after saving new snapshots during the REFRESH_STORAGE_STATS system task (runs hourly by default):

import { checkStorageAlerts } from "@/services/storage/storage-alert-service";

// Called automatically after saveStorageSnapshots()
await checkStorageAlerts(storageVolumeEntries);

Each StorageVolumeEntry must include a configId (the AdapterConfig.id of the destination). Entries without a configId are skipped.

Disabling Alerts for a Destination

If all three alert types are disabled for a destination, the service short-circuits and skips the state load entirely — no database queries are made for that destination.

Disabling an alert type while it is active automatically resets its state (clears active and lastNotifiedAt), so it does not fire again immediately if re-enabled.

Related

• System Tasks - REFRESH_STORAGE_STATS task that triggers checks
• Notification Events - event types and notification configuration
• Integrity Checks - file-level verification of stored backups