The Processor API allows developers to define and connect custom processors and to interact with state stores. With the Processor API, you can define arbitrary stream processors that process one received record at a time, and connect these processors with their associated state stores to compose the processor topology that represents a customized processing logic. Source code for data-wrangler is also included to provide parsing and formatting capabilities for incoming messages
To start with kafka - Step 1: Download the code Download the 2.2.0 release and un-tar it.
tar -xzf kafka_2.12-2.2.0.tgz cd kafka_2.12-2.2.0
Step 2: Start the server Kafka uses ZooKeeper so you need to first start a ZooKeeper server if you don't already have one. You can use the convenience script packaged with kafka to get a quick-and-dirty single-node ZooKeeper instance.
bin/zookeeper-server-start.sh config/zookeeper.properties [2013-04-22 15:01:37,495] INFO Reading configuration from: config/zookeeper.properties (org.apache.zookeeper.server.quorum.QuorumPeerConfig) ... Now start the Kafka server:
bin/kafka-server-start.sh config/server.properties [2013-04-22 15:01:47,028] INFO Verifying properties (kafka.utils.VerifiableProperties) [2013-04-22 15:01:47,051] INFO Property socket.send.buffer.bytes is overridden to 1048576 (kafka.utils.VerifiableProperties) ... Step 3: Create a topic Let's create a topic named "test" with a single partition and only one replica:
bin/kafka-topics.sh --create --bootstrap-server localhost:9092 --replication-factor 1 --partitions 1 --topic test We can now see that topic if we run the list topic command:
bin/kafka-topics.sh --list --bootstrap-server localhost:9092 test Alternatively, instead of manually creating topics you can also configure your brokers to auto-create topics when a non-existent topic is published to.
Step 4: Send some messages Kafka comes with a command line client that will take input from a file or from standard input and send it out as messages to the Kafka cluster. By default, each line will be sent as a separate message.
Run the producer and then type a few messages into the console to send to the server.
bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test This is a message This is another message