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Meridian VMS

Failover

Meridian VMS includes a failover service that monitors the health of recording servers and automatically rebalances cameras when a server becomes unavailable. This ensures continuous recording coverage even when hardware or network failures occur.

Health Monitoring

Section titled “Health Monitoring”

The failover service continuously tracks the health of every recording server based on periodic status reports (heartbeats). Each recording server reports its status at regular intervals, including per-camera health and storage information.

Server States

Section titled “Server States”
                    heartbeat received
    ┌─────────┐ ─────────────────────> ┌─────────┐
    │ Offline │                        │ Online  │
    └─────────┘ <───────────────────── └─────────┘
                    heartbeat missed
StateMeaning
OnlineServer is operational and reporting regularly
DegradedServer is running but some cameras are experiencing recording issues
OfflineServer has stopped reporting and is presumed down or unreachable

Detecting Server Failure

Section titled “Detecting Server Failure”

The failover service identifies a server failure when:

  1. Missed heartbeats — The server has not reported status within the expected time window.
  2. Consecutive failures — To avoid reacting to brief network interruptions, the service requires multiple consecutive missed heartbeats before classifying a server as offline.

Automatic Camera Rebalancing

Section titled “Automatic Camera Rebalancing”

When a recording server is confirmed offline, its cameras are no longer being recorded. The failover service can automatically redistribute these cameras to healthy servers.

How Rebalancing Works

Section titled “How Rebalancing Works”
  1. Identify affected cameras — All cameras assigned to the offline server are identified.
  2. Select target servers — Healthy servers with available capacity are selected as candidates.
  3. Redistribute cameras — Affected cameras are distributed across healthy servers, balanced by capacity and current load.
  4. Apply changes — Configuration updates are pushed to the target servers, which begin recording the reassigned cameras immediately.

Capacity Considerations

Section titled “Capacity Considerations”

The rebalancing process takes into account:

  • Network bandwidth — Existing camera load plus reassigned cameras should not exceed the target server’s network capacity.
  • Disk space — The target server must have sufficient free space for additional recordings.
  • Camera count — Cameras are distributed evenly to avoid overloading a single server.

Recovery

Section titled “Recovery”

When a previously offline server comes back online:

  1. The server resumes sending heartbeat reports to the management server.
  2. Its status is updated to online.
  3. Cameras that were rebalanced to other servers remain on their new assignments.
  4. An administrator can manually reassign cameras back to the recovered server if desired.

Best Practices

Section titled “Best Practices”