Querying Kafka Topics

Scenario

You can query existing Kafka topics on MRS.

Procedure

1. Go to the Kafka service page.
   • For versions earlier than MRS 3.x, click the cluster name to go to the cluster details page and choose Components > Kafka.
     

     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.

2. Click KafkaTopicMonitor.

   All topics are displayed in the list by default. You can view the number of partitions and replicas of the topics.

3. Click the desired topic in the list to view its details.
   

   If the following operations are performed, Kafka topic monitoring may not be displayed:

   • Capacity expansion or reduction has been performed on Kafka or ZooKeeper.
   • Instances have been added to or deleted from Kafka or ZooKeeper.
   • The Elasticsearch service is reinstalled.
   • Kafka is switched to another ZooKeeper service.

   Perform the following steps to rectify the fault:

   1. Log in to the active OMS node of the cluster and run the following command to switch to user omm:

      su - omm

   2. Restart the CEP service.

      restart_app cep

      Wait for 3 minutes and check the Kafka topic monitoring again.