Failover

To avoid having a single point of failure in a multi-node site, when you add a new node to your deployment you can assign it the role of failover candidate. This means that any server or node in your Qlik Sense site can perform the same role as the central node. The role of the central node can now be swapped, for example if the central node has been offline for more than 10 minutes.

Automatic failover

After you have configured a node to become a failover candidate, each node in your site will regularly check the primary node (central node) for a heartbeat. If there is no communication between the primary node and the other nodes in the site after 10 minutes then the primary node will be replaced by the next available node. If more than one node is set as a failover candidate each node will compete to get a lock on a database field and the winner becomes the central node. There is an additional field in the QMC to show which node is currently the central node.

Manually migrating the central node

If you decide that you want to move the central node to another node in your site, you can manually migrate it using the the following REST API calls:

  • Get /qrs/serverNodeConfiguration to get a list of server GUIDs.
  • Do an empty POST to /qrs/failover/tonode/{serverNodeConfigurationID} to retrieve the ID of the node you want to migrate to.