Topic Management

Where the actions live

The topic selector carries the actions. Its list has a Refreshand a + Add New at the foot, and a three-dot menu sits beside it for the selected topic.

Every menu item acts on the selected topic, so they stay disabled until one is chosen. Delete sits at the foot, apart and in red, since it cannot be undone.

Creating a topic

+ Add New opens a dialog for aname,partitions andreplication factor. The factor is capped at the cluster's broker count and told to you there, rather than sent for the broker to reject.

More settings opens the topic configs:cleanup.policy,retention.ms,retention.bytes,max.message.bytes,min.insync.replicas andcompression.type. Only what you set travels; a field left blank leaves the broker default in place, so a plain create carries no overrides.

A cluster that runs its own create policy can refuse the topic. The dialog says so by name, and says that the policy's reason stays on the broker: Kafka does not pass it to a client.

Describe

Describe is a read-only view of the topic as the broker reports it: the partition count and replication factor, then each partition with its leader, replicas and in-sync set. A partition whose ISR is short of its replicas is under-replicated, and shown in red.

The config set is listed with its effective values. A value at the broker default is marked (default); an override is shown plainly, so what has been changed stands out from what has not.

Topic settings

Topic settings opens the editor, filled from the same describe. The name and replication factor are read-only, since Kafka changes neither in place. Partitions can only be raised, so the field is floored at the current count.

Every config is filled with its effective value, defaults marked the way describe marks them. Editing a default turns it into an override; clearing an override, or picking Default in a dropdown, resets it to the broker default. Configs you do not touch are left as they were, including any set outside this set. Apply makes the config and partition changes together.

Deleting a topic

Delete is the last item in the menu, set apart below a divider and shown in red, because it cannot be undone. It asks first: a dialog names the topic and warns that deleting it takes every message in it with it.

Once you confirm, the topic leaves the list at once and the selection clears. If the consumer was reading that topic, its watch is stopped, since the topic it was on is gone. Deleting is asynchronous on the broker, so a freshRefresh right after may still list it for a moment while the cluster's metadata catches up.

Switching topics

Moving the selector to a different topic hands back what belonged to the old one, so nothing rides across by accident. The producer draft resets at once: the value, key, headers, partition and config. The reader resets too, its start position, buffer and the messages on screen, unless a watch is still running on the old topic, in which case those are kept until you stop it.