Changing the Broker Storage Directory

Scenario

This section applies to MRS 3.x or later.

When a broker storage directory is added, the MRS cluster administrator needs to change the broker storage directory on FusionInsight Manager, to ensure that the Kafka can work properly. The new topic partition will be generated in the directory that has fewest partitions. Changing the ZooKeeper storage directory includes the following scenarios:

Because Kafka does not detect disk capacity, ensure that the disk quantity and capacity configured for each Broker instance are the same.

• Change the storage directory of the Broker role. In this way, the storage directories of all Broker instances are changed.
• Change the storage directory of a single Broker instance. In this way, only the storage directory of this Broker instance is changed, and the storage directories of other Broker instances remain the same.

Impact on the System

• Changing the Broker role storage directory requires the restart of services. The services cannot be accessed during the restart.
• The storage directory of a single Broker instance can be changed only after the instance is restarted. The instance cannot provide services during the restart.
• The directory for storing service parameter configurations must also be updated.

Prerequisites

• New disks have been prepared and installed on each data node, and the disks are formatted.
• The Kafka client has been installed.
• When you change the storage directory of a single Broker instance, the number of active Broker instances must be greater than the number of backups specified during topic creation.

Procedure

Changing the storage directory of the Kafka role

1. Log in as user root to each node on which the Kafka service is installed, and perform the following operations:
   1. Create a target directory.

      For example, to create the target directory ${BIGDATA_DATA_HOME}/kafka/data2, run the following command:

      mkdir ${BIGDATA_DATA_HOME}/kafka/data2

   2. Mount the directory to the new disk. For example, mount ${BIGDATA_DATA_HOME}/kafka/data2 to the new disk.
   3. Modify permissions on the new directory.

      For example, to modify permissions on the ${BIGDATA_DATA_HOME}/kafka/data2 directory, run the following commands:

      chmod 700 ${BIGDATA_DATA_HOME}/kafka/data2 -R and chown omm:wheel ${BIGDATA_DATA_HOME}/kafka/data2 -R

2. Log in to FusionInsight Manager for clusters of MRS 3.x or later and choose Cluster > Services > Kafka > Configurations.
3. Add a new directory to the end of the default value of log.dirs.

   Enter log.dirs in the search box and add the new directory to the end of the default value of the log.dirs configuration item. Use commas (,) to separate multiple directories. For example:

   ${BIGDATA_DATA_HOME}/kafka/data1/kafka-logs,${BIGDATA_DATA_HOME}/kafka/data2/kafka-logs

4. Click Save, and then click OK. When Operation succeeded is displayed, click Finish.
5. Choose Cluster > Services > Kafka. In the upper right corner, choose More > Restart Service to restart the Kafka service.

Changing the storage directory of a single Kafka instance

6. Log in to the Broker node as user root and perform the following operations:
   1. Create a target directory.

      For example, to create the target directory ${BIGDATA_DATA_HOME}/kafka/data2, run the following command:

      mkdir ${BIGDATA_DATA_HOME}/kafka/data2

   2. Mount the directory to the new disk. For example, mount ${BIGDATA_DATA_HOME}/kafka/data2 to the new disk.
   3. Modify permissions on the new directory.

      For example, to modify permissions on the ${BIGDATA_DATA_HOME}/kafka/data2 directory, run the following commands:

      chmod 700 ${BIGDATA_DATA_HOME}/kafka/data2 -R and chown omm:wheel ${BIGDATA_DATA_HOME}/kafka/data2 -R

7. Log in to FusionInsight Manager for MRS 3.x or later, and choose Cluster > Services > Kafka > Instance.
8. Click the specified broker instance and switch to Instance Configurations.

   Enter log.dirs in the search box and add the new directory to the end of the default value of the log.dirs configuration item. Use commas (,) to separate multiple directories, for example, ${BIGDATA_DATA_HOME}/kafka/data1/kafka-logs,${BIGDATA_DATA_HOME}/kafka/data2/kafka-logs.

9. Click Save, and then click OK. A message is displayed, indicating that the operation is successful. Click Finish.
10. On the Broker instance page, choose More > Restart Instance to restart the Broker instance.