Initially, Source processors receive data from one or more Kafka topics and deserialize it before forwarding them to the Stream Processor node which contains the main transformation or computation logic. Finally, Sink Processor writes the processed data into one or more output Kafka Topic or to a ...
流(stream)是Kafka Streams提供的最重要的抽象,它代表的是一个无限的、不断更新的数据集。一个流就是由一个有序的、可重放的、支持故障转移的不可变的数据记录(data record)序列,其中每个数据记录被定义为一个键值对。Kafka流的基本结构如图所示。 Kafka流基本结构 一个流处理器(stream processor)是处理拓扑中的...
processor, 从上一个node中接收数据并处理数据,可以继续传给下一个processor,也可以传给sink sink,从processor中获取数据并写入topics, 构建好了Topology之后,传给KafkaStreams,启动后就能按照这个Topology运行了。 StreamsBuilder,high-level DSL strem构建器,stream()返回KStream,table()返回KTable, ...
在Kafka Streams DSL中,聚合操作的输入流可以是KStream或KTable,但是输出流将始终是KTable,允许Kafka Streams在生成或发出之后,最后抵达的记录更新聚合的值。当这种晚到到达的记录发生,聚合KStream或KTtable只是发出一个新的聚合值。由于输出是KTable,所以在后续的处理步骤中,具有key的旧值将被新值覆盖。
For example, a retail application might take in input streams of sales and shipments, and output a stream of reorders and price adjustments computed off this data. It is possible to do simple processing directly using the producer and consumer APIs. However for more complex transformations Kafka...
publicclassSimpleStreamProcessor{publicstaticvoidmain(String[]args){Propertiesprops=KafkaStreamsConfig.createProperties();StreamsBuilderbuilder=newStreamsBuilder();KStream<String,String>sourceStream=builder.stream("input-topic");sourceStream.mapValues(value->"Processed: "+value).to("output-topic");Kafka...
However, with their processor topologies independently, each thread can execute one or more tasks. For example, below image describes one stream thread running two stream tasks. Test where you you stand in Kafka ...
KafkaMusic (Interactive Queries) Interactive Queries, State Stores, REST API Java 7+ Example MapFunction DSL, stateless transformations, map() Java 8+ Example MixAndMatch DSL + Processor API Integrating DSL and Processor API Java 8+ Example PassThrough DSL, stream(), to() Java 7+ Example...
"stream-processing-service");//设置servers地址props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "kafka-broker1:9092");StreamsBuilder builder = new StreamsBuilder();//构建流KStream<String, String> userActions = builder.stream("TopicA");//对流进行处理KTable<String, Long> user...
例如,“listener.name.sasl_ssl.scram-sha-256.sasl.jaas.config=com.example.ScramLoginModule” sasl.kerberos.service.name Kafka 运行的 Kerberos 主体名称。这可以在 Kafka 的 JAAS 配置或 Kafka 的配置中定义。 sasl.login.callback.handler.class 实现AuthenticateCallbackHandler 接口的 SASL 登录回调处理程序...