Kafka DescribeLogDirs Request Wire Format v4 — Binary Protocol Layout

What is DescribeLogDirs?

Shows per-broker disk usage, replica offset lag, and which replicas are mid-move (futureLogDir), via kafka-log-dirs.sh. High offsetLag on a follower replica indicates it's lagging behind the leader; compare with the ISR list to assess replication health.

Schema
{
  "Topics": [{
      "Topic": string,
      "Partitions": [int32]
  }]?
}

Example
{
  "Topics": [{
      "Topic": "orders",
      "Partitions": [1, 2, 3]
  }]?
}