Learn how to use the kafka-log-dirs tool.

The kafka-log-dirs tool allows user to query a list of replicas per log directory on a broker. The tool provides information that is required for optimizing replica assignment across brokers.

To retrieve replica assignment information, run the following command:
kafka-log-dirs --describe --bootstrap-server hostname:port --broker-list broker 1, broker 2 --topic-list topic 1, topic 2
If no topic is specified with the --topic-list option, then all topics are queried. If no broker is specified with the --broker-list option, then all brokers are queried. If a log directory is offline, the log directory will be marked offline in the script output. Error example:
On successful execution, the tool prints a list of partitions per log directory for the specified topics and brokers. The list contains information on topic partition, size, offset lag, and reassignment state. Example output:
    "brokers": [
            "broker": 86,
            "logDirs": [
                    "error": null,
                    "logDir": "/var/local/kafka/data",
                    "partitions": [
                            "isFuture": false,
                            "offsetLag": 0,
                            "partition": "mytopic1-2",
                            "size": 0
    "version": 1

The following table gives an overview of the information provided by the output of the kafka-log-dirs tool.

Table 1. Contents of the kafka-log-dirs Output
Property Description
broker Displays the ID of the broker.
error Indicates if there is a problem with the disk that hosts the topic partition. If an error is detected, org.apache.kafka.common.errors.KafkaStorageException is displayed. If no error is detected, the value is null.
logDir Specifies the location of the log directory. Returns an absolute path.
isfuture The reassignment state of the partition. This property shows whether there is currently replica movement underway between the log directories.
offsetLag Displays the offset lag of the partition.
partition Displays the name of the partition.
size Displays the size of the partition in bytes.