Creating a Kafka topic

To use Kafka topics to store events in Event Streams, create and configure a Kafka topic.

Using the UI

1. Log in to the Event Streams UI from a supported web browser (see how to determine the login URL for your Event Streams UI).
2. Click Home in the primary navigation.
3. Click the Create a topic tile.

4. Enter a topic name in the Topic name field, for example, my-topic. This is the name of the topic that an application will be producing to or consuming from.

   Click Next.

5. Enter the number of Partitions, for example, 1. Partitions are used for scaling and distributing topic data across the Apache Kafka brokers. For the purposes of a basic starter application, using only 1 partition is sufficient.

   Click Next.

6. Select a Message retention, for example, A day. This is how long messages are retained before they are deleted.

   Click Next.

7. Select a replication factor in Replicas, for example, Replication factor: 1. This is how many copies of a topic will be made for high availability. For production environments, select Replication factor: 3 as a minimum.

8. Click Create topic. The topic is created and can be viewed from the Topics tab located in the primary navigation.

Note: To view all configuration options you can set for topics, set Show all available options to On.

Note: Kafka supports additional topic configuration settings. Enable Show all available options to access more detailed configuration settings if required.

Using the CLI

1. Log in to your cluster as an administrator by using the IBM Cloud Pak CLI:
   cloudctl login -a https://<cluster_address>:<cluster_router_https_port>

   Find out how to retrieve the login URL for your Event Streams CLI.

2. Run the following command to initialize the Event Streams CLI on the cluster:
   cloudctl es init

3. Run the following command to create a topic:

   cloudctl es topic-create --name <topic-name> --partitions <number-of-partitions> --replication-factor <replication-factor>

   For example, to create a topic called my-topic that has 1 partition, a replication factor of 1, and 1 day set for message retention time (provided in milliseconds):

   cloudctl es topic-create --name my-topic --partitions 1 --replication-factor 1 --config retention.ms=86400000

   Important: Do not set <replication-factor> to a greater value than the number of available brokers.

Note: To view all configuration options you can set for topics, use the help option as follows: cloudctl es topic-create --help

Kafka supports additional topic configuration settings. Extend the topic creation command with one or more --config <property>=<value> properties to apply additional configuration settings. The following additional properties are currently supported:

• cleanup.policy
• compression.type
• delete.retention.ms
• file.delete.delay.ms
• flush.messages
• flush.ms
• follower.replication.throttled.replicas
• index.interval.bytes
• leader.replication.throttled.replicas
• max.message.bytes
• message.format.version
• message.timestamp.difference.max.ms
• message.timestamp.type
• min.cleanable.dirty.ratio
• min.compaction.lag.ms
• min.insync.replicas
• preallocate
• retention.bytes
• retention.ms
• segment.bytes
• segment.index.bytes
• segment.jitter.ms
• segment.ms
• unclean.leader.election.enable