def maxConnections = getInt()

in core/src/main/scala/kafka/server/KafkaConfig.scala [1460:1588]


  def maxConnections = getInt(KafkaConfig.MaxConnectionsProp)
  def maxConnectionCreationRate = getInt(KafkaConfig.MaxConnectionCreationRateProp)
  val connectionsMaxIdleMs = getLong(KafkaConfig.ConnectionsMaxIdleMsProp)
  val failedAuthenticationDelayMs = getInt(KafkaConfig.FailedAuthenticationDelayMsProp)

  /***************** rack configuration **************/
  val rack = Option(getString(KafkaConfig.RackProp))
  val replicaSelectorClassName = Option(getString(KafkaConfig.ReplicaSelectorClassProp))

  /** ********* Log Configuration ***********/
  val autoCreateTopicsEnable = getBoolean(KafkaConfig.AutoCreateTopicsEnableProp)
  val numPartitions = getInt(KafkaConfig.NumPartitionsProp)
  val logDirs = CoreUtils.parseCsvList(Option(getString(KafkaConfig.LogDirsProp)).getOrElse(getString(KafkaConfig.LogDirProp)))
  def logSegmentBytes = getInt(KafkaConfig.LogSegmentBytesProp)
  def logFlushIntervalMessages = getLong(KafkaConfig.LogFlushIntervalMessagesProp)
  val logCleanerThreads = getInt(KafkaConfig.LogCleanerThreadsProp)
  def numRecoveryThreadsPerDataDir = getInt(KafkaConfig.NumRecoveryThreadsPerDataDirProp)
  val logFlushSchedulerIntervalMs = getLong(KafkaConfig.LogFlushSchedulerIntervalMsProp)
  val logFlushOffsetCheckpointIntervalMs = getInt(KafkaConfig.LogFlushOffsetCheckpointIntervalMsProp).toLong
  val logFlushStartOffsetCheckpointIntervalMs = getInt(KafkaConfig.LogFlushStartOffsetCheckpointIntervalMsProp).toLong
  val logCleanupIntervalMs = getLong(KafkaConfig.LogCleanupIntervalMsProp)
  def logCleanupPolicy = getList(KafkaConfig.LogCleanupPolicyProp)
  val offsetsRetentionMinutes = getInt(KafkaConfig.OffsetsRetentionMinutesProp)
  val offsetsRetentionCheckIntervalMs = getLong(KafkaConfig.OffsetsRetentionCheckIntervalMsProp)
  def logRetentionBytes = getLong(KafkaConfig.LogRetentionBytesProp)
  val logCleanerDedupeBufferSize = getLong(KafkaConfig.LogCleanerDedupeBufferSizeProp)
  val logCleanerDedupeBufferLoadFactor = getDouble(KafkaConfig.LogCleanerDedupeBufferLoadFactorProp)
  val logCleanerIoBufferSize = getInt(KafkaConfig.LogCleanerIoBufferSizeProp)
  val logCleanerIoMaxBytesPerSecond = getDouble(KafkaConfig.LogCleanerIoMaxBytesPerSecondProp)
  def logCleanerDeleteRetentionMs = getLong(KafkaConfig.LogCleanerDeleteRetentionMsProp)
  def logCleanerMinCompactionLagMs = getLong(KafkaConfig.LogCleanerMinCompactionLagMsProp)
  def logCleanerMaxCompactionLagMs = getLong(KafkaConfig.LogCleanerMaxCompactionLagMsProp)
  val logCleanerBackoffMs = getLong(KafkaConfig.LogCleanerBackoffMsProp)
  def logCleanerMinCleanRatio = getDouble(KafkaConfig.LogCleanerMinCleanRatioProp)
  val logCleanerEnable = getBoolean(KafkaConfig.LogCleanerEnableProp)
  def logIndexSizeMaxBytes = getInt(KafkaConfig.LogIndexSizeMaxBytesProp)
  def logIndexIntervalBytes = getInt(KafkaConfig.LogIndexIntervalBytesProp)
  def logDeleteDelayMs = getLong(KafkaConfig.LogDeleteDelayMsProp)
  def logRollTimeMillis: java.lang.Long = Option(getLong(KafkaConfig.LogRollTimeMillisProp)).getOrElse(60 * 60 * 1000L * getInt(KafkaConfig.LogRollTimeHoursProp))
  def logRollTimeJitterMillis: java.lang.Long = Option(getLong(KafkaConfig.LogRollTimeJitterMillisProp)).getOrElse(60 * 60 * 1000L * getInt(KafkaConfig.LogRollTimeJitterHoursProp))
  def logFlushIntervalMs: java.lang.Long = Option(getLong(KafkaConfig.LogFlushIntervalMsProp)).getOrElse(getLong(KafkaConfig.LogFlushSchedulerIntervalMsProp))
  def minInSyncReplicas = getInt(KafkaConfig.MinInSyncReplicasProp)
  def logPreAllocateEnable: java.lang.Boolean = getBoolean(KafkaConfig.LogPreAllocateProp)
  // We keep the user-provided String as `ApiVersion.apply` can choose a slightly different version (eg if `0.10.0`
  // is passed, `0.10.0-IV0` may be picked)
  val logMessageFormatVersionString = getString(KafkaConfig.LogMessageFormatVersionProp)
  val logMessageFormatVersion = ApiVersion(logMessageFormatVersionString)
  def logMessageTimestampType = TimestampType.forName(getString(KafkaConfig.LogMessageTimestampTypeProp))
  def logMessageTimestampDifferenceMaxMs: Long = getLong(KafkaConfig.LogMessageTimestampDifferenceMaxMsProp)
  def logMessageDownConversionEnable: Boolean = getBoolean(KafkaConfig.LogMessageDownConversionEnableProp)

  /** ********* Replication configuration ***********/
  val controllerSocketTimeoutMs: Int = getInt(KafkaConfig.ControllerSocketTimeoutMsProp)
  val defaultReplicationFactor: Int = getInt(KafkaConfig.DefaultReplicationFactorProp)
  val replicaLagTimeMaxMs = getLong(KafkaConfig.ReplicaLagTimeMaxMsProp)
  val replicaSocketTimeoutMs = getInt(KafkaConfig.ReplicaSocketTimeoutMsProp)
  val replicaSocketReceiveBufferBytes = getInt(KafkaConfig.ReplicaSocketReceiveBufferBytesProp)
  val replicaFetchMaxBytes = getInt(KafkaConfig.ReplicaFetchMaxBytesProp)
  val replicaFetchWaitMaxMs = getInt(KafkaConfig.ReplicaFetchWaitMaxMsProp)
  val replicaFetchMinBytes = getInt(KafkaConfig.ReplicaFetchMinBytesProp)
  val replicaFetchResponseMaxBytes = getInt(KafkaConfig.ReplicaFetchResponseMaxBytesProp)
  val replicaFetchBackoffMs = getInt(KafkaConfig.ReplicaFetchBackoffMsProp)
  def numReplicaFetchers = getInt(KafkaConfig.NumReplicaFetchersProp)
  val replicaHighWatermarkCheckpointIntervalMs = getLong(KafkaConfig.ReplicaHighWatermarkCheckpointIntervalMsProp)
  val fetchPurgatoryPurgeIntervalRequests = getInt(KafkaConfig.FetchPurgatoryPurgeIntervalRequestsProp)
  val producerPurgatoryPurgeIntervalRequests = getInt(KafkaConfig.ProducerPurgatoryPurgeIntervalRequestsProp)
  val deleteRecordsPurgatoryPurgeIntervalRequests = getInt(KafkaConfig.DeleteRecordsPurgatoryPurgeIntervalRequestsProp)
  val autoLeaderRebalanceEnable = getBoolean(KafkaConfig.AutoLeaderRebalanceEnableProp)
  val leaderImbalancePerBrokerPercentage = getInt(KafkaConfig.LeaderImbalancePerBrokerPercentageProp)
  val leaderImbalanceCheckIntervalSeconds = getLong(KafkaConfig.LeaderImbalanceCheckIntervalSecondsProp)
  def uncleanLeaderElectionEnable: java.lang.Boolean = getBoolean(KafkaConfig.UncleanLeaderElectionEnableProp)

  // We keep the user-provided String as `ApiVersion.apply` can choose a slightly different version (eg if `0.10.0`
  // is passed, `0.10.0-IV0` may be picked)
  val interBrokerProtocolVersionString = getString(KafkaConfig.InterBrokerProtocolVersionProp)
  val interBrokerProtocolVersion = ApiVersion(interBrokerProtocolVersionString)

  /** ********* Controlled shutdown configuration ***********/
  val controlledShutdownMaxRetries = getInt(KafkaConfig.ControlledShutdownMaxRetriesProp)
  val controlledShutdownRetryBackoffMs = getLong(KafkaConfig.ControlledShutdownRetryBackoffMsProp)
  val controlledShutdownEnable = getBoolean(KafkaConfig.ControlledShutdownEnableProp)

  /** ********* Feature configuration ***********/
  def isFeatureVersioningEnabled = interBrokerProtocolVersion >= KAFKA_2_7_IV0

  /** ********* Group coordinator configuration ***********/
  val groupMinSessionTimeoutMs = getInt(KafkaConfig.GroupMinSessionTimeoutMsProp)
  val groupMaxSessionTimeoutMs = getInt(KafkaConfig.GroupMaxSessionTimeoutMsProp)
  val groupInitialRebalanceDelay = getInt(KafkaConfig.GroupInitialRebalanceDelayMsProp)
  val groupMaxSize = getInt(KafkaConfig.GroupMaxSizeProp)

  /** ********* Offset management configuration ***********/
  val offsetMetadataMaxSize = getInt(KafkaConfig.OffsetMetadataMaxSizeProp)
  val offsetsLoadBufferSize = getInt(KafkaConfig.OffsetsLoadBufferSizeProp)
  val offsetsTopicReplicationFactor = getShort(KafkaConfig.OffsetsTopicReplicationFactorProp)
  val offsetsTopicPartitions = getInt(KafkaConfig.OffsetsTopicPartitionsProp)
  val offsetCommitTimeoutMs = getInt(KafkaConfig.OffsetCommitTimeoutMsProp)
  val offsetCommitRequiredAcks = getShort(KafkaConfig.OffsetCommitRequiredAcksProp)
  val offsetsTopicSegmentBytes = getInt(KafkaConfig.OffsetsTopicSegmentBytesProp)
  val offsetsTopicCompressionCodec = Option(getInt(KafkaConfig.OffsetsTopicCompressionCodecProp)).map(value => CompressionCodec.getCompressionCodec(value)).orNull

  /** ********* Transaction management configuration ***********/
  val transactionalIdExpirationMs = getInt(KafkaConfig.TransactionalIdExpirationMsProp)
  val transactionMaxTimeoutMs = getInt(KafkaConfig.TransactionsMaxTimeoutMsProp)
  val transactionTopicMinISR = getInt(KafkaConfig.TransactionsTopicMinISRProp)
  val transactionsLoadBufferSize = getInt(KafkaConfig.TransactionsLoadBufferSizeProp)
  val transactionTopicReplicationFactor = getShort(KafkaConfig.TransactionsTopicReplicationFactorProp)
  val transactionTopicPartitions = getInt(KafkaConfig.TransactionsTopicPartitionsProp)
  val transactionTopicSegmentBytes = getInt(KafkaConfig.TransactionsTopicSegmentBytesProp)
  val transactionAbortTimedOutTransactionCleanupIntervalMs = getInt(KafkaConfig.TransactionsAbortTimedOutTransactionCleanupIntervalMsProp)
  val transactionRemoveExpiredTransactionalIdCleanupIntervalMs = getInt(KafkaConfig.TransactionsRemoveExpiredTransactionalIdCleanupIntervalMsProp)


  /** ********* Metric Configuration **************/
  val metricNumSamples = getInt(KafkaConfig.MetricNumSamplesProp)
  val metricSampleWindowMs = getLong(KafkaConfig.MetricSampleWindowMsProp)
  val metricRecordingLevel = getString(KafkaConfig.MetricRecordingLevelProp)

  /** ********* SSL/SASL Configuration **************/
  // Security configs may be overridden for listeners, so it is not safe to use the base values
  // Hence the base SSL/SASL configs are not fields of KafkaConfig, listener configs should be
  // retrieved using KafkaConfig#valuesWithPrefixOverride
  private def saslEnabledMechanisms(listenerName: ListenerName): Set[String] = {
    val value = valuesWithPrefixOverride(listenerName.configPrefix).get(KafkaConfig.SaslEnabledMechanismsProp)
    if (value != null)
      value.asInstanceOf[util.List[String]].asScala.toSet
    else
      Set.empty[String]
  }