ReplicaFetcherThread

ReplicaFetcherThread is an uninterruptible AbstractFetcherThread that…FIXME

ReplicaFetcherThread is used (managed) by ReplicaFetcherManager.

ReplicaFetcherThread is created when ReplicaFetcherManager is requested to create a fetcher thread (when…FIXME).

ReplicaFetcherThread uses replica.fetch.backoff.ms configuration property for the fetchBackOffMs.

ReplicaFetcherThread uses replica.fetch.max.bytes configuration property for…FIXME

Creating ReplicaFetcherThread Instance

ReplicaFetcherThread takes the following to be created:

Name
Fetcher ID
Source BrokerEndPoint
KafkaConfig
ReplicaManager
Metrics
Time
ReplicaQuota
Optional BlockingSend (default: None)

ReplicaFetcherThread initializes the internal properties.

`earliestOrLatestOffset` Internal Method

earliestOrLatestOffset(topicPartition: TopicPartition, earliestOrLatest: Long): Long

earliestOrLatestOffset…FIXME

Note	`earliestOrLatestOffset` is used when…FIXME

`fetchEpochsFromLeader` Method

fetchEpochsFromLeader(partitions: Map[TopicPartition, Int]): Map[TopicPartition, EpochEndOffset]

Note	`fetchEpochsFromLeader` is a part of AbstractFetcherThread Contract.

fetchEpochsFromLeader…FIXME

`processPartitionData` Method

processPartitionData(
  topicPartition: TopicPartition,
  fetchOffset: Long,
  partitionData: FetchData): Option[LogAppendInfo]

Note	`processPartitionData` is part of the AbstractFetcherThread Contract to…FIXME.

processPartitionData…FIXME

`truncate` Method

truncate(
  tp: TopicPartition,
  offsetTruncationState: OffsetTruncationState): Unit

Note	`truncate` is a part of AbstractFetcherThread Contract.

truncate…FIXME

`truncateFullyAndStartAt` Method

truncateFullyAndStartAt(topicPartition: TopicPartition, offset: Long): Unit

Note	`truncateFullyAndStartAt` is a part of AbstractFetcherThread Contract.

truncateFullyAndStartAt…FIXME

`latestEpoch` Method

latestEpoch(topicPartition: TopicPartition): Option[Int]

Note	`latestEpoch` is a part of AbstractFetcherThread Contract to get the latest (current) leader epoch for the given `TopicPartition`.

latestEpoch requests the ReplicaManager for the local partition replica (or throw an exception) for the given TopicPartition and requests the replica for the latest (current) leader epoch.

`isOffsetForLeaderEpochSupported` Method

isOffsetForLeaderEpochSupported: Boolean

Note	`isOffsetForLeaderEpochSupported` is part of the AbstractFetcherThread Contract to control whether a `OffsetsForLeaderEpochRequest` is supported (that was added in Kafka 0.11.0.0).

isOffsetForLeaderEpochSupported simply returns the brokerSupportsLeaderEpochRequest flag.

`buildFetch` Method

buildFetch(
  partitionMap: Map[TopicPartition, PartitionFetchState]
): ResultWithPartitions[Option[FetchRequest.Builder]]

Note	`buildFetch` is part of the AbstractFetcherThread Contract to…FIXME

buildFetch requests the FetchSessionHandler for a new Builder.

For every TopicPartition (in the given partitionMap), buildFetch finds the logStartOffset of the local log (using the ReplicaManager) and adds them as PartitionData to the Builder.

buildFetch requests the Builder to create a FetchRequestData.

In the end, buildFetch creates a FetchRequest.Builder for the local partition replica.

Internal Properties

Name Description

Name	Description
`brokerSupportsLeaderEpochRequest`	Flag that says whether the inter.broker.protocol.version is `0.11.0-IV2` or above Used in isOffsetForLeaderEpochSupported
`fetchSessionHandler`	`FetchSessionHandler` (with the logContext and the ID of the source broker)

brokerSupportsLeaderEpochRequest

Flag that says whether the inter.broker.protocol.version is 0.11.0-IV2 or above

Used in isOffsetForLeaderEpochSupported

fetchSessionHandler

FetchSessionHandler (with the logContext and the ID of the source broker)

ReplicaFetcherThread