Multi-node site

In a multi-node site, the site is spread out across two or more nodes that share the same set of data and license key. Multi-node sites can be used for many purposes:

• Add capacity
• Add resilience
• Move apps or workload onto a specific node
• Fit with customer network deployments

In a multi-node site, each node has a local copy of the data that it needs to fulfill its role, which means that the node can operate independently in the event of a server or network failure. Each node can read and write its local data and a synchronization mechanism in Qlik Sense distributes the changes to other nodes in the site.

One node is configured to be the central node, which is responsible for controlling the multi-node site. The central node is also the point through which the other nodes in the site synchronize their data.

The synchronization in a multi-node site is two-way:

• The central node requests updates from the rim nodes every 15 seconds.
• Each rim node initiates a synchronization session with the central node every 15 seconds.

When changes are made on each node, the resulting transactions are recorded in a transaction log. During the synchronization, the latest set of transactions from the log is sent to the other nodes and replayed.

The synchronization is not visible to the users, who can continue to work in their apps while new data is synchronized in the background.