Kafka OffsetCommit Response Wire Format v4

What is OffsetCommit?

Every consumer sends this after processing records to checkpoint its position into __consumer_offsets. Commit failures during rebalances (REBALANCE_IN_PROGRESS, ILLEGAL_GENERATION) are the root cause of duplicate processing in at-least-once consumers.

Wire Diagram

Response Header

message_size int32 · 4B

correlation_id int32 · 4B

OffsetCommitResponse v4

ThrottleTimeMs int32 · 4B

Topics array

Name string

Partitions array

PartitionIndex int32 · 4B

ErrorCode int16 · 2B

Schema & Example

Schema
{
  "ThrottleTimeMs": int32,
  "Topics": [{
      "Name": string,
      "Partitions": [{
          "PartitionIndex": int32,
          "ErrorCode": int16
      }]
  }]
}

Example
{
  "ThrottleTimeMs": 0,
  "Topics": [{
      "Name": "orders",
      "Partitions": [{
          "PartitionIndex": 3,
          "ErrorCode": 0
      }]
  }]
}

Kafka OffsetCommit Response Wire Format v4 — Binary Protocol Layout

What is OffsetCommit?

Wire Diagram

Schema & Example