// OffsetCommitRequest commits offsets for consumed topics / partitions in
// a group.
OffsetCommitRequest => key 8, max version 8, flexible v8+, group coordinator
  // Group is the group this request is committing offsets to.
  Group: string
  // Generation being -1 and group being empty means the group is being used
  // to store offsets only. No generation validation, no rebalancing.
  Generation: int32(-1) // v1+
  // MemberID is the ID of the client issuing this request in the group.
  MemberID: string // v1+
  // InstanceID is the instance ID of this member in the group (KIP-345).
  InstanceID: nullable-string // v7+
  // RetentionTimeMillis is how long this commit will persist in Kafka.
  //
  // This was introduced in v2, replacing an individual topic/partition's
  // Timestamp from v1, and was removed in v5 with Kafka 2.1.0.
  //
  // This was removed because rarely committing consumers could have their
  // offsets expired before committing, even though the consumer was still
  // active. After restarting or rebalancing, the consumer would now not know
  // the last committed offset and would have to start at the beginning or end,
  // leading to duplicates or log loss.
  //
  // Post 2.1.0, if this field is empty, offsets are only deleted once the
  // group is empty. Read KIP-211 for more details.
  RetentionTimeMillis: int64(-1) // v2-v4
  // Topics is contains topics and partitions for which to commit offsets.
  Topics: [=>]
    // Topic is a topic to commit offsets for.
    Topic: string
    // Partitions contains partitions in a topic for which to commit offsets.
    Partitions: [=>]
      // Partition if a partition to commit offsets for.
      Partition: int32
      // Offset is an offset to commit.
      Offset: int64
      // Timestamp is the first iteration of tracking how long offset commits
      // should persist in Kafka. This field only existed for v1.
      // The expiration would be timestamp + offset.retention.minutes, or, if
      // timestamp was zero, current time + offset.retention.minutes.
      Timestamp: int64(-1) // v1-v1
      // LeaderEpoch, proposed in KIP-320 and introduced in Kafka 2.1.0,
      // is the leader epoch of the record this request is committing.
      //
      // The initial leader epoch can be determined from a MetadataResponse.
      // To skip log truncation checking, use -1.
      LeaderEpoch: int32(-1) // v6+
      // Metadata is optional data to include with committing the offset. This
      // can contain information such as which node is doing the committing, etc.
      Metadata: nullable-string

// OffsetCommitResponse is returned from an OffsetCommitRequest.
OffsetCommitResponse =>
  ThrottleMillis(4) // v3+
  // Topics contains responses for each topic / partition in the commit request.
  Topics: [=>]
    // Topic is the topic this offset commit response corresponds to.
    Topic: string
    // Partitions contains responses for each requested partition in
    // a topic.
    Partitions: [=>]
      // Partition is the partition in a topic this array slot corresponds to.
      Partition: int32
      // ErrorCode is the error for this partition response.
      //
      // GROUP_AUTHORIZATION_FAILED is returned if the client is not authorized
      // for the group.
      //
      // TOPIC_AUTHORIZATION_FAILED is returned if the client is not authorized
      // for the topic / partition.
      //
      // UNKNOWN_TOPIC_OR_PARTITION is returned if the topic / partition does
      // not exist.
      //
      // OFFSET_METADATA_TOO_LARGE is returned if the request metadata is
      // larger than the brokers offset.metadata.max.bytes.
      //
      // INVALID_GROUP_ID is returned in the requested group ID is invalid.
      //
      // COORDINATOR_NOT_AVAILABLE is returned if the coordinator is not available
      // (due to the requested broker shutting down or it has not completed startup).
      //
      // COORDINATOR_LOAD_IN_PROGRESS is returned if the group is loading.
      //
      // NOT_COORDINATOR is returned if the requested broker is not the coordinator
      // for the requested group.
      //
      // ILLEGAL_GENERATION is returned if the request's generation ID is invalid.
      //
      // UNKNOWN_MEMBER_ID is returned if the group is dead or the group does not
      // know of the request's member ID.
      //
      // REBALANCE_IN_PROGRESS is returned if the group is finishing a rebalance.
      //
      // INVALID_COMMIT_OFFSET_SIZE is returned if the offset commit results in
      // a record batch that is too large (likely due to large metadata).
      ErrorCode: int16