This Knowledgebase article provides information about configuring failover timeout (also referred to as the Heartbeat Missed event in earlier versions of Neverfail Heartbeat).
You can configure how long Neverfail waits after it detects a missed heartbeat before it takes a pre-configured action. When choosing this value, consider the following:
- Setting the number of heartbeats to a high value increases the time interval before a failover. As a result, the active server might stay unavailable too long before the passive server initiates the failover process.
- Setting the number of heartbeats to a low value for a server pair that has low Channel bandwidth, may cause split-brain syndrome. For more information about split-brain syndrome, see Knowledgebase Article #516 — Resolve Two Active Servers .
For Neverfail Heartbeat V6.0 and more recent:
- Open the Neverfail Heartbeat Management Client, and navigate to the Server : Monitoring screen.
- Click Configure Failover... to open the Server Monitoring: Failover Configuration dialog.
- Type a new numeric value (seconds) in the Failover timeout text box or use the arrow buttons to set a new value.
Mark or clear the following optional checkboxes to select the actions
to take if the specified Failover timeout is exceeded:
- Failover from Primary server to Secondary server if channel heartbeat is lost for failover timeout
- Failover from Secondary server to Primary server if channel heartbeat is lost for failover timeout
- Prevent failover or auto switchover while not synchornized (recommended)
- Prevent failover if channel heartbeat is lost but Active server is still visible tother servers (recommended)
- Click OK to accept the changes or Cancel to dismiss the dialog without making any changes.
For Neverfail Heartbeat V5.5.[n] and older:
The passive server issues heartbeats at regular intervals of time to ensure the active server is online and available. If the active server becomes unresponsive due to a hardware crash, lost channel connection, or power outage, these heartbeats can be missed. When the Max Heartbeats Missed Before Failover is reached, the passive server initiates a failover. To disable automatic failovers initiated by the passive server, you can configure the Max Heartbeats Missed before Failover to reflect all-nines.
- From the Neverfail Heartbeat Management Client, open Communications > Configuration tab.
- Set the Max Heartbeats Missed Before Failover field to reflect all-nines.
- Click Apply to save the changes.