Create and change topics

Each change needs a cluster with writable: true and the privilege the section names. The UI shows an action only when you hold its privilege, and never on an internal topic.

Create a topicCopy Anchor Link

You need create_topics.

1. On Topics, select Create topic.
2. Enter the Name.
3. Optional: enter Partitions and Replication factor. An empty field uses the broker default.
4. Optional: to set configs, select Add config and enter a name, such as retention.ms, and a value.
5. Select Create topic. klens opens the new topic.

Change a topic configCopy Anchor Link

You need topic_configs to see the configs and alter_topic_configs to change them.

1. Open a topic and select the Configuration tab. To see only the configs that differ from their default, turn on Overrides only.
2. Select the row of the config.
3. Enter the Value and select Save. The topic now overrides the broker value.

To follow the broker value again, open the row and select Remove override. A sensitive value starts empty and shows Hidden. Rows with a lock icon are read-only.

Add partitionsCopy Anchor Link

You need add_partitions.

1. Open a topic, open the ⋯ menu, and select Add partitions.
2. Enter the new Partition count. It must be larger than the current count.
3. Select Add partitions.

Kafka cannot remove partitions later. A record with a key may land in another partition than earlier records with the same key, so consumers that rely on key order can see records out of order.

Delete recordsCopy Anchor Link

You need delete_records. Kafka deletes records by moving the start offset of a partition forward.

1. Open a topic, open the ⋯ menu, and select Delete records.
2. Pick a Partition, or keep All partitions.
3. Optional: enter Before offset. Without it, klens deletes every record up to the end of the log.
4. Type the topic name to confirm, and select Delete records.

To delete the records before a given record, open the record and select Delete the records before this one. The dialog opens with its partition and offset.

Kafka keeps the records of a compacted topic. To delete records from one, add delete to its cleanup.policy first.

Delete a topicCopy Anchor Link

You need delete_topics.

1. Open a topic, open the ⋯ menu, and select Delete topic.
2. Type the topic name to confirm, and select Delete topic.

Kafka deletes the topic and every record in it. You cannot undo the deletion.