Modifying Kafka Topic Configurations

This section describes how to modify configurations in Table 1 of a Kafka topic on the console.

Modifying Synchronous Replication, Synchronous Flushing, Message Timestamp, Max. Message Size, or Description does not require an instance restart.

**Table 1** Kafka topic configuration parameters
Parameter	Description
Partitions	Number of partitions in a topic. For details about how to change, see Changing Kafka Partition Quantity.
Aging Time (h)	Maximum message retention. For details about how to change, see Changing Kafka Message Retention Period.
Replicas	Number of replicas of each topic partition. To modify it, see Modifying Kafka Topic Replicas.
Synchronous Replication	A message is returned to the client only after the message creation request has been received and the message has been acknowledged by all replicas.
Synchronous Flushing	Enabled: A message is immediately flushed to disk once it is created, bringing higher reliability. Disabled: A message is stored in the memory instead of being immediately flushed to disk once created.
Message Timestamp	Timestamp type of a message. Options: CreateTime: time when the producer created the message. LogAppendTime: time when the broker appended the message to the log.
Max. Message Size	Maximum size of messages to be processed in batches. If message compression is enabled, this parameter indicates the size after compression. If this value is increased and the consumer version is earlier than 0.10.2, the consumers' fetch size must also be increased so that they can obtain the latest value.
Description	Topic description.

Procedure

Log in to the console.
Click in the upper left corner to select the region where your instance is located.
Click and choose Middleware > Distributed Message Service (for Kafka) to open the console of DMS for Kafka.
In the navigation pane, choose Kafka Instances.
Click the desired instance to go to the instance details page.
In the navigation pane, choose Topics.
Modify topic configurations in either of the following ways:
- Select one or more topics and click Edit Topic above the topic list.
- In the row containing the desired topic, click Edit.
In the Edit Topic dialog box, change configurations and click OK.
Note:
- If there is only one replica, Synchronous Replication cannot be enabled.
- After enabling synchronous replication, set acks to all or –1 on the client. Otherwise, this function will not take effect.