Managing Messages in Kafka Topics¶
Scenario¶
You can produce or consume messages in Kafka topics using the MRS cluster client. For clusters with Kerberos authentication enabled, you must have the permission to perform these operations.
Prerequisites¶
You have installed the Kafka client.
Procedure¶
Go to the Kafka service page.
For versions earlier than MRS 1.9.2, log in to MRS Manager and choose Services > Kafka.
For MRS 1.9.2 or later, click the cluster name on the MRS console and choose Components > Kafka.
Note
If the Components tab is unavailable, complete IAM user synchronization first. (On the Dashboard page, click Synchronize on the right side of IAM User Sync to synchronize IAM users.)
For MRS 3.x or later, log in to FusionInsight Manager. For details, see Accessing FusionInsight Manager (MRS 3.x or Later). Choose Cluster > Name of the desired cluster > Services > Kafka.
Click instance. Query the IP addresses of the Kafka instances.
Record the IP address of any Kafka instance.
Prepare the client based on service requirements. Log in to the node where the client is installed.
Run the following command to switch to the client directory, for example, /opt/client/Kafka/kafka/bin.
cd /opt/client/Kafka/kafka/bin
Run the following command to configure environment variables:
source /opt/client/bigdata_env
For clusters with Kerberos authentication enabled, run the following command to authenticate the user. For clusters with Kerberos authentication disabled, skip this step.
kinit Kafka user
Example:
kinit admin
Manage messages in Kafka topics using the following commands:
Producing messages
sh kafka-console-producer.sh --broker-list IP address of the node where the Kafka instance resides:9092 --topic Topic name --producer.config /opt/client/Kafka/kafka/config/producer.properties
You can input specified information as the messages produced by the producer and then press Enter to send the messages. To end message producing, press Ctrl + C to exit.
Consuming messages
sh kafka-console-consumer.sh --topic Topic name --bootstrap-server IP address of the node where the Kafka instance resides:9092 --consumer.config /opt/client/Kafka/kafka/config/consumer.properties
In the configuration file, group.id (indicating the consumer group) is set to example-group1 by default. Users can change the value as required. The value takes effect each time consumption occurs.
By default, the system reads unprocessed messages in the current consumer group when the command is executed. If a new consumer group is specified in the configuration file and the --from-beginning parameter is added to the command, the system reads all messages that have not been automatically deleted in Kafka.
Note
For the IP address of the node where the Kafka instance locates, use the IP address of any broker instance.
If Kerberos authentication is enabled, change the port to 21007.
By default, the ZooKeeper's clientPort value is 2181.
For MRS 1.6.2 or earlier, the value of ZooKeeper's clientPort defaults to 24002. For details, see List of Open Source Component Ports.