clients/src/main/resources/common/message/ApiVersionsResponse.json

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// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License.  You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
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{
  "apiKey": 18,
  "type": "response",
  "name": "ApiVersionsResponse",
  // Version 1 adds throttle time to the response.
  //
  // Starting in version 2, on quota violation, brokers send out responses before throttling.
  //
  // Version 3 is the first flexible version. Tagged fields are only supported in the body but
  // not in the header. The length of the header must not change in order to guarantee the
  // backward compatibility.
  //
  // Starting from Apache Kafka 2.4 (KIP-511), ApiKeys field is populated with the supported
  // versions of the ApiVersionsRequest when an UNSUPPORTED_VERSION error is returned.
  //
  // Version 4 fixes KAFKA-17011, which blocked SupportedFeatures.MinVersion from being 0.
  "validVersions": "0-4",
  "flexibleVersions": "3+",
  "fields": [
    { "name": "ErrorCode", "type": "int16", "versions": "0+",
      "about": "The top-level error code." },
    { "name": "ApiKeys", "type": "[]ApiVersion", "versions": "0+",
      "about": "The APIs supported by the broker.", "fields": [
      { "name": "ApiKey", "type": "int16", "versions": "0+", "mapKey": true,
        "about": "The API index." },
      { "name": "MinVersion", "type": "int16", "versions": "0+",
        "about": "The minimum supported version, inclusive." },
      { "name": "MaxVersion", "type": "int16", "versions": "0+",
        "about": "The maximum supported version, inclusive." }
    ]},
    { "name": "ThrottleTimeMs", "type": "int32", "versions": "1+", "ignorable": true,
      "about": "The duration in milliseconds for which the request was throttled due to a quota violation, or zero if the request did not violate any quota." },
    { "name": "SupportedFeatures", "type": "[]SupportedFeatureKey", "ignorable": true,
      "versions": "3+", "tag": 0, "taggedVersions": "3+",
      "about": "Features supported by the broker. Note: in v0-v3, features with MinSupportedVersion = 0 are omitted.",
      "fields": [
        { "name": "Name", "type": "string", "versions": "3+", "mapKey": true,
          "about": "The name of the feature." },
        { "name": "MinVersion", "type": "int16", "versions": "3+",
          "about": "The minimum supported version for the feature." },
        { "name": "MaxVersion", "type": "int16", "versions": "3+",
          "about": "The maximum supported version for the feature." }
      ]
    },
    { "name": "FinalizedFeaturesEpoch", "type": "int64", "versions": "3+",
      "tag": 1, "taggedVersions": "3+", "default": "-1", "ignorable": true,
      "about": "The monotonically increasing epoch for the finalized features information. Valid values are >= 0. A value of -1 is special and represents unknown epoch." },
    { "name": "FinalizedFeatures", "type": "[]FinalizedFeatureKey", "ignorable": true,
      "versions": "3+", "tag": 2, "taggedVersions": "3+",
      "about": "List of cluster-wide finalized features. The information is valid only if FinalizedFeaturesEpoch >= 0.",
      "fields": [
        { "name": "Name", "type": "string", "versions":  "3+", "mapKey": true,
          "about": "The name of the feature." },
        { "name": "MaxVersionLevel", "type": "int16", "versions":  "3+",
          "about": "The cluster-wide finalized max version level for the feature." },
        { "name": "MinVersionLevel", "type": "int16", "versions":  "3+",
          "about": "The cluster-wide finalized min version level for the feature." }
      ]
    },
    { "name": "ZkMigrationReady", "type": "bool", "versions": "3+", "taggedVersions": "3+",
      "tag": 3, "ignorable": true, "default": "false",
      "about": "Set by a KRaft controller if the required configurations for ZK migration are present." }
  ]
}