Viewing and Resetting Kafka Consumption Offsets

Notes and Constraints

Messages may be consumed more than once after the offset is reset. Exercise caution when performing this operation.

Prerequisites

The consumer offset cannot be reset on the fly. You must first stop consumption of the desired consumer group. After a client is stopped, the server considers the client offline only after the time period specified in ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG (1000 ms by default).

Viewing Consumer Offsets (Console)

1. Log in to the console.
2. Click in the upper left corner to select the region where your instance is located.
3. Click in the upper left corner and choose Application > Distributed Message Service for Kafka to open the Kafka instance list.
4. Click the desired instance to go to the instance details page.
5. In the navigation pane, choose Instance > Consumer Groups.
6. Click the name of the desired consumer group.
7. On the Consumer Offset tab page, view the list of topics that the consumer group has subscribed to, topic quantity, total number of messages accumulated in the topic, and offset of each partition.

   Table 1 Consumer offset parameters

   Parameter	Description
   Topic Name	Name of a topic that the consumer group has subscribed to
   Partitions	Number of partitions in a topic
   Cumulative Messages	Number of messages that are not consumed by the consumer group in a topic This parameter indicates the instantaneous value at the sampling. The value of its corresponding metric in monitoring is sampled every minute. These values may vary. For more information, see Why Is the Number of Stacked Messages Monitored as 0 when Messages Are Stacked?.
   Partition	Partition number in a topic
   Accumulated Messages	Number of messages that are not consumed by the consumer group in a partition
   Offset	Offset of this partition
   Latest Offset	Maximum message position of a partition
   ID	ID of the consumer who consumes messages in this partition
   Address	Address of the consumer who consumes messages in this partition
   Client ID	Client identifier. This client is used to connect to a Kafka instance and consume messages in this partition.

8. (Optional) To query the consumer offsets of a specific topic, enter the topic name in the search box and press Enter.
9. (Optional) To export the consumption progress to the local, refer to either of the following ways.
   • Select the desired topics and choose Export > Export selected data to an XLSX file to export the consumption progress of specific topics.
   • Choose Export > Export all data to an XLSX file to export the consumption progress of all topics.

Viewing Consumer Offsets (Kafka CLI)

• 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} --offsets --describe --all-groups

  Parameter description: connection-address indicates the Kafka instance address, which can be obtained in the Connection area on the Overview page on the Kafka console.

  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 --offsets --describe --all-groups
  
  Consumer group '__consumer-group-dial-test' has no active members.
  
  GROUP                      TOPIC           PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG             CONSUMER-ID     HOST            CLIENT-ID
  __consumer-group-dial-test __dms_dial_test 0          350             350             0               -               -               -
  __consumer-group-dial-test __dms_dial_test 1          350             350             0               -               -               -
  __consumer-group-dial-test __dms_dial_test 2          350             350             0               -               -               -
  
  Consumer group 'test' has no active members.
  
  GROUP           TOPIC           PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG             CONSUMER-ID     HOST            CLIENT-ID
  test            topic-01        0          5               5               0               -               -               -
  test            topic-01        1          3               3               0               -               -               -
  test            topic-01        2          10              10              0               -               -               -
  [root@ecs-kafka bin]#

• For a Kafka instance with ciphertext access enabled, do as follows:
  1. (Optional) If the username and password, and the SSL certificate has been configured, skip this step and go to 2. Otherwise, do as follows:

     Create the ssl-user-config.properties file in the /config directory of the Kafka client. Add the username and password, and the SSL certificate configuration by referring to 3.

  2. Run the following command in the /bin directory of the Kafka client:

     ./kafka-consumer-groups.sh --bootstrap-server {connection-address} --offsets --describe --all-groups --command-config ../config/{ssl-user-config.properties} 

     Table 2 Consumer offset query parameters

     Parameter	Description
     connection-address	Connection address of a Kafka instance. To obtain the address, choose Overview > Connection.
     ssl-user-config.properties	Configuration file name. This file contains username, password, and SSL certificate information.

     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 --offsets --describe --all-groups --command-config ../config/ssl-user-config.properties
     
     Consumer group '__consumer-group-dial-test' has no active members.
     
     GROUP                      TOPIC           PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG             CONSUMER-ID     HOST            CLIENT-ID
     __consumer-group-dial-test __dms_dial_test 0          347             347             0               -               -               -
     __consumer-group-dial-test __dms_dial_test 1          347             347             0               -               -               -
     __consumer-group-dial-test __dms_dial_test 2          347             347             0               -               -               -
     
     Consumer group 'test' has no active members.
     
     GROUP           TOPIC           PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG             CONSUMER-ID     HOST            CLIENT-ID
     test            topic-01        0          5               5               0               -               -               -
     test            topic-01        1          3               3               0               -               -               -
     test            topic-01        2          10              10              0               -               -               -
     [root@ecs-kafka bin]#

Resetting Consumer Offsets

1. Log in to the console.
2. Click in the upper left corner to select the region where your instance is located.
3. Click in the upper left corner and choose Application > Distributed Message Service for Kafka to open the Kafka instance list.
4. Click the desired instance to go to the instance details page.
5. In the navigation pane, choose Instance > Consumer Groups.
6. Click the name of the desired consumer group.
7. On the Consumer Offset tab page, you can perform the following operations:
   • To reset the consumer offset of all partitions of a single topic, click Reset Consumer Offset in the row containing the desired topic.
   • To reset the consumer offset of a single partition of a single topic, click Reset Consumer Offset in the row containing the desired partition.
   • To reset the consumer offset in all partitions of all topics, click Reset Offset.

8. In the displayed Reset Consumer Offset dialog box, set the parameters by referring to Table 3.

   Table 3 Parameters for resetting the consumer offset

   Parameter	Description
   Reset By	You can reset an offset by: Time: Reset the offset to the specified time. Offset: Reset the offset to the specified position. Reset Offset works with a specific time.
   Time	Set this parameter if Reset By is set to Time. Select a time point. After the reset is complete, retrieval starts from this time point. Earliest: earliest offset Custom: a custom time point Latest: latest offset
   Offset	Set this parameter if Reset By is set to Offset. Enter an offset, which is greater than or equal to 0. After the reset is complete, retrieval starts from this offset.

9. Click OK.
10. Click Yes in the confirmation dialog box. The consumer offset is reset.

    On the Consumer Offset tab page, click before the topic whose consumer offset has been reset, and view the new value in the Offset column.