Create topics and groups - ApsaraMQ for Kafka - Alibaba Cloud Documentation Center

Before you use ApsaraMQ for Kafka to send and receive messages, you must create topics and groups on the deployed ApsaraMQ for Kafka instance. In ApsaraMQ for Kafka, producers send messages to specific topics and then consumers subscribe to the topics to consume messages. Before consumers consume messages, the group to which the consumers belong must subscribe to the corresponding topics. A group can subscribe to multiple topics and a topic can be subscribed to by multiple groups.

Prerequisites

An ApsaraMQ for Kafka instance is purchased and deployed based on the network type.

Step 1: Create a topic

Log on to the ApsaraMQ for Kafka console.
In the Resource Distribution section of the Overview page, select the region where the ApsaraMQ for Kafka instance that you want to manage resides.
Important
You must create topics in the region where your Elastic Compute Service (ECS) instance is deployed. A topic cannot be used across regions. For example, if the producers and consumers of messages run on an ECS instance that is deployed in the China (Beijing) region, the topic must also be created in the China (Beijing) region.
On the Instances page, click the name of the instance that you want to manage.
In the left-side navigation pane, click Topics.
On the Topics page, click Create Topic.

In the Create Topic panel, specify the properties of the topic and click OK.

Parameter	Description	Example
Name	The topic name.	demo
Description	The topic description.	demo test
Partitions	The number of partitions in the topic.	12
Storage Engine Note You can specify the storage engine type only if you use a Professional Edition instance. If you use a Standard Edition instance, cloud storage is selected by default.	The type of the storage engine that is used to store messages in the topic. ApsaraMQ for Kafka supports the following types of storage engines: Cloud Storage: If you select this value, the system uses Alibaba Cloud disks for the topic and stores data in three replicas in distributed mode. This storage engine features low latency, high performance, long durability, and high reliability. If you set the Instance Edition parameter to Standard (High Write) when you created the instance, you can set this parameter only to Cloud Storage. Local Storage: If you select this value, the system uses the in-sync replicas (ISR) algorithm of open source Apache Kafka and stores data in three replicas in distributed mode.	Cloud Storage
Message Type	The message type of the topic. Valid values: Normal Message: By default, messages that have the same key are stored in the same partition in the order in which the messages are sent. If a broker in the cluster fails, the order of messages that are stored in the partitions may not be preserved. If you set the Storage Engine parameter to Cloud Storage, this parameter is automatically set to Normal Message. Partitionally Ordered Message: By default, messages that have the same key are stored in the same partition in the order in which the messages are sent. If a broker in the cluster fails, messages are still stored in the partitions in the order in which the messages are sent. Messages in some partitions cannot be sent until the partitions are restored. If you set the Storage Engine parameter to Local Storage, this parameter is automatically set to Partitionally Ordered Message.	Normal Message
Log Cleanup Policy	The log cleanup policy that is used by the topic. If you set the Storage Engine parameter to Local Storage, you must configure the Log Cleanup Policy parameter. You can set the Storage Engine parameter to Local Storage only if you use an ApsaraMQ for Kafka Professional Edition instance. ApsaraMQ for Kafka provides the following log cleanup policies: Delete: the default log cleanup policy. If sufficient storage space is available in the system, messages are retained based on the maximum retention period. After the storage usage exceeds 85%, the system deletes the earliest stored messages to ensure service availability. Compact: the log compaction policy that is used in Apache Kafka. Log compaction ensures that the latest values are retained for messages that have the same key. This policy is suitable for scenarios such as restoring a failed system or reloading the cache after a system restarts. For example, when you use Kafka Connect or Confluent Schema Registry, you must store the information about the system status and configurations in a log-compacted topic. Important You can use log-compacted topics only in specific cloud-native components, such as Kafka Connect and Confluent Schema Registry. For more information, see aliware-kafka-demos.	Compact
Tag	The tags that you want to attach to the topic.	demo

After a topic is created, you can view the topic on the Topics page.

Step 2: Create a group

Log on to the ApsaraMQ for Kafka console.
In the Resource Distribution section of the Overview page, select the region where the ApsaraMQ for Kafka instance that you want to manage resides.
On the Instances page, click the name of the instance that you want to manage.
In the left-side navigation pane, click Groups.
On the Groups page, click Create Group.
In the Create Group panel, enter a group name in the Group ID field and a group description in the Description field, attach tags to the group, and then click OK.
After a consumer group is created, you can view the consumer group on the Groups page.

References

If you do not want to manually create topics or groups, you can enable the flexible group creation feature and the automatic topic creation feature. For more information, see Use the flexible group creation feature and Automatically create topics.
For information about how to create resources by calling API operations, see CreateTopic and CreateConsumerGroup.
After resources are created, you can use an SDK to send and receive messages based on the network type. For more information, see Step 4: Use an SDK to send and receive messages.