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Configuring Topics

Hazelcast provides a distribution mechanism for publishing messages that are delivered to multiple subscribers. This is known as a publish/subscribe (pub/sub) messaging model. Publishing and subscription operations are cluster wide. When a member subscribes to a topic, it is registered to receive messages published by any member in the cluster, including any new members that joined after you added the listener. You can create and configure topics using the Topic custom resource.

Configuring a Topic Resource

You can use any of the following configuration options in the Topic resource. For more information, see the API Reference.

Field Description


Name of the topic configuration that you’re creating. If empty, the custom resource (CR) name is used.


Defines the name of the Hazelcast resource for which the topic configuration is created.


When true, all nodes listening to the same topic get their messages in the same order.


When true, enables multi-threaded processing of incoming messages. Otherwise, a single thread handles all topic messages.

You cannot enable multi-threading when global ordering is in use.

Example Configuration

The following Topic custom resource creates a topic configuration for the Hazelcast custom resource that is defined in the hazelcastResourceName field.

Example configuration
apiVersion: hazelcast.com/v1alpha1
kind: Topic
  name: topic-sample
  hazelcastResourceName: hazelcast-sample
  globalOrderingEnabled: true
  multiThreadingEnabled: false

After creating the Topic resource, use the following command to check its status:

kubectl get topic topic-sample -o wide
topic-sample    Success