Baseline Topology

If Ignite persistence is enabled, Ignite enforces the baseline topology concept which represents a set of server nodes in the cluster that will persist data on disk.

Usually, when the cluster is started for the first time with Ignite persistence on, the cluster will be considered inactive, disallowing any CRUD operations. This is done to avoid possible performance, usability, and consistency issues that might occur if the cluster is being restarted and applications start modifying the data that may be persisted on the nodes that have not yet rejoined the cluster. Therefore, you need to define the baseline topology for the cluster with Ignite persistence enabled, and after that, the topology can be either maintained manually or automatically by GridGain.

Note that the baseline topology is not set when the cluster, with Ignite persistence enabled, is started for the first time; that’s the only time when a manual intervention is needed. So, once all the nodes that should belong to the baseline topology are up and running, you can set the topology via code, GridGain Web Console, or a command line tool, and let GridGain handle the automatic cluster activation routines going forward.

This chapter shows how to activate baseline topology from the web console. See the Baseline Topology documentation for more information on other activation methods.

First, select the Baseline Topology option from the Monitoring drop down menu.

Then, use the Cluster inactive/active toggle switch to activate the cluster.

The following image shows that the cluster is active:

Once the cluster is active, you can select nodes to include in the baseline topology, as shown below: