Deleting a Kafka Consumer Group

You can delete a consumer group in either of the following ways:

Method 1: Delete a consumer group on the console.
Method 2: Use Kafka CLI to delete a consumer group. (Ensure that the Kafka instance version is the same as the CLI version.)

Constraints

If auto.create.groups.enable is set to true, the consumer group status is EMPTY, and no offset has been submitted, the system automatically deletes the consumer group 10 minutes later.
If auto.create.groups.enable is set to false, the system does not automatically delete consumer groups. You can manually delete them.
If a consumer group has never committed an offset, the group will be deleted after the Kafka instance restarts.

Prerequisites

The status of the consumer group to be deleted is EMPTY.

Method 1: Deleting a Consumer Group on the Console

Log in to the console.
Click in the upper left corner to select a region.

Select the region where your Kafka instance is located.
Click and choose Middleware > Distributed Message Service (for Kafka) to open the console of DMS for Kafka.
Click the desired Kafka instance to view the instance details.
In the navigation pane, choose the Consumer Groups tab.
Delete consumer groups using either of the following methods:
- Select one or more consumer groups and click Delete Consumer Group above the consumer group list.
- In the row containing the consumer group you want to delete, click Delete.
A consumer group can be deleted only when its status is EMPTY.

Consumer group statuses include:
- DEAD: The consumer group has no member or metadata.
- EMPTY: The consumer group has metadata but has no member.
- PREPARING_REBALANCE: The consumer group is to be rebalanced.
- COMPLETING_REBALANCE: All members have joined the consumer group.
- STABLE: Members in the consumer group can consume messages normally.
In the displayed Delete Consumer Group dialog box, click OK.

Method 2: Using the CLI to Delete a Consumer Group

The following uses Linux as an example.

For a Kafka instance with ciphertext access disabled, run the following command in the /bin directory of the Kafka client:

./kafka-consumer-groups.sh --bootstrap-server ${connection-address} --delete --group ${consumer-group-name}

Parameter description:

connection-address: can be obtained from the Connection area on the Basic Information page on the Kafka console.
consumer-group-name: consumer group name.

Example:

[root@ecs-kafka bin]# ./kafka-consumer-groups.sh --bootstrap-server 192.168.xx.xx:9092,192.168.xx.xx:9092,192.168.xx.xx:9092 --delete --group group-01
Deletion of requested consumer groups ('group-01') was successful.
[root@ecs-kafka bin]#

For a Kafka instance with ciphertext access enabled, do as follows:
1. (Optional) Modify the client configuration file.
  View Security Protocol in the Connection area on the Basic Information page on the Kafka console. The configuration settings vary depending on the protocol.
  - SASL_PLAINTEXT: Skip this step if the username and password are already set. Otherwise, create the ssl-user-config.properties file in the /config directory on the Kafka client and add the following content to the file:
```
security.protocol=SASL_PLAINTEXT
# If the SASL mechanism is SCRAM-SHA-512, configure as follows:
sasl.jaas.config=org.apache.kafka.common.security.scram.ScramLoginModule required \
username="**********" \
password="**********";        
sasl.mechanism=SCRAM-SHA-512
# If the SASL mechanism is PLAIN, configure as follows:
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
username="**********" \
password="**********";        
sasl.mechanism=PLAIN
```
    Parameter description: username and password are the ones you set when enabling ciphertext access for the first time or when creating a user.
  - SASL_SSL: Skip this step if the username, password, and SSL certificate are already set. Otherwise, create the ssl-user-config.properties file in the /config directory on the Kafka client and add the following content to the file:
```
security.protocol=SASL_SSL
ssl.truststore.location={ssl_truststore_path}
ssl.truststore.password=dms@kafka
ssl.endpoint.identification.algorithm=
# If the SASL mechanism is SCRAM-SHA-512, configure as follows:
sasl.jaas.config=org.apache.kafka.common.security.scram.ScramLoginModule required \
username="**********" \
password="**********";        
sasl.mechanism=SCRAM-SHA-512
# If the SASL mechanism is PLAIN, configure as follows:
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
username="**********" \
password="**********";        
sasl.mechanism=PLAIN
```
    Parameter description:
    - ssl.truststore.location: path for storing the client.jks certificate. Even in Windows, you need to use slashes (/) for the certificate path. Do not use backslashes (\), which are used by default for paths in Windows. Otherwise, the client will fail to obtain the certificate.
    - ssl.truststore.password: server certificate password, which must be set to dms@kafka and cannot be changed.
    - ssl.endpoint.identification.algorithm: whether to verify the certificate domain name. This parameter must be left blank, which indicates disabling domain name verification.
    - username and password: username and password you set when enabling ciphertext access for the first time or when creating a user.
2. In the /bin directory of the Kafka client, run the following command:
```
./kafka-consumer-groups.sh --bootstrap-server ${connection-address} --delete --group ${consumer-group-name} --command-config ../config/ssl-user-config.properties
```
  Parameter description:
  - connection-address: can be obtained from the Connection area on the Basic Information page on the Kafka console.
  - consumer-group-name: consumer group name.
  Example:
```
[root@ecs-kafka bin]# ./kafka-consumer-groups.sh --bootstrap-server 192.168.xx.xx:9093,192.168.xx.xx:9093,192.168.xx.xx:9093 --delete --group group-02 --command-config ../config/ssl-user-config.properties
Deletion of requested consumer groups ('group-02') was successful.
[root@ecs-kafka bin]#
```