Kafka生产者类图

Builder

RecordAccumulator

+append()+drain()

-client

ClientRequest

ProducerBatch

-sender

sender线程

add

ProducerInterceptors

+onSend()+onAcknowledgement()

使用KafkaProducer客户端发送消息（ProducerRecord），需要经历拦截器（Interceptor）、序列化器（Serializer）和分区器（Partitioner）等一系列的作用

ProducerInterceptor

-accumulator

request

drain

main线程

ProduceRequest

send

interfacePartitioner

+partition()

-interceptors

Deque

一条消息（ProducerRecord）在经过拦截器、序列化器、分区器处理之后，被存入到RecordAccumulator中。在RecordAccumulator中维护了一个名为batches的Map，其以分区信息（TopicPartition）为键，双端队列（Deque）为值，这个队列由若干ProducerBatch组成，而一个ProducerBatch又包含若干条消息

-clientId:String-producerConfig:ProducerConfig

+KafkaProducer()+send(ProducerRecord)

interfaceRunnable

+run()

以broker节点为维度，存放发往broker节点的封装后的InFlightRequest消息，根据配置（max.in.flight.requests.per.connection）可能限制每个broker的缓存请求

-inFlightRequests

a:TopicPartitiona IN node1

InFlightRequests

+add()+canSendMore():boolean

sender线程在实例化KafkaProducer时被创建，并以守护线程的方式运行

进一步封装消息

c:TopicPartitiona IN node1

interfaceSerializer

+serialize()+configure()

b:TopicPartitiona IN node2

append

将从RecordAccumulator获取的消息集合封装

-partitioner

-keySerializer

-valueSerializer

InFlightRequest

destination:Stringheader:RequestHeadercallback:RequestCompletionHandler

+InFlightRequest()+completed()+disconnected()

NetworkClient

-selector:Selectable

AbstractRequest

0...n

Sender

+Sender()+run()-runOnce()-sendProducerData()-sendProduceRequests()-sendProduceRequest()