Kafka Consumer From Beginning

Now the real fun begins. Consumer architecture. Note that this is an experimental feature in Spark 1. The kafka-consumer-groups tool can be used to list all consumer groups, describe a consumer group, delete consumer group info, or reset consumer group offsets. sh --bootstrap-server localhost:9092 --topic TOPIC --consumer-property group. Thus, as a first step to reprocess data, the committed offsets need to be reset. sh --bootstrap-server BootstrapBrokerString--consumer. On the other hand, if a new consumer group is started in an existing topic, then there is no offset store. This code will need to be callable from the unit test. Kafka and the ELK Stack — usually these two are part of the same architectural solution, Kafka acting as a buffer in front of Logstash to ensure resiliency. Rejected by society, the Monster vows revenge on his creator. The Kafka storage plugin configuration contains the kafkaConsumerProps property which supports typical Kafka consumer properties, as described in Kafka Consumer Configs. Reset Offset for a topic. 5 in my LAB to check all components before upgrade DEV and PROD cluster, I realized that Atlas was not working properly missing the informations for lineage. Get the consumer offsets for a topic. This client class contains logic to read user input from the console and send that input as a message to the Kafka server. /bin/kafka-console-consumer. The Kafka brokers are an important part of the puzzle, but do not provide the Consumer Group behavior directly. bin/kafka-console-consumer. As explained in a previous post. > bin/kafka-console-consumer. The received data is stored in Spark’s worker/executor memory as well as to the WAL (replicated on HDFS). A consumer can subscribe to the super topic e. Thus, as a first step to reprocess data, the committed offsets need to be reset. Open Closed Principle makes that objects,methods should be open for extensions, but closed for modification. OffsetRequest. Kafka is a distributed system. consumer: A reference to the Kafka Consumer object. 1:9092 –topic second-topic –from-beginning –partition 0 hai this is my new messge this is new messge ^CProcessed a total of 3 messages [email protected] / $ kafka-console-consumer –bootstrap-server 127. Partition re-assignment makes the consumer replay Kafka messages beginning with last committed offsets. On the above pre-requisites session, we have started zookeeper, Kafka server and created one hello-topic and also started Kafka consumer console. If that broker is down for some, consumer will mark it as dead. Enter the name of the group of which you want this consumer to be a member. In the producer stream, type some messages. Open a new command prompt and start the Apache Kafka- C:\kafka_2. hydra --from-beginning. The poll duration of the Kafka consumer. This will put the kafka offset for the topic of your choice to the beginning so once you start reading you will get all records. Consumer group. syang:kafka_2. 8 and beyond. Question by Kennon Rodrigues Jun 01, 2018 at 11:27 AM Kafka Atlas hdp-2. In this article we'll see how to set it up and examine the format of the data. You can use the Kafka console consumer tool with IBM Event Streams. This example shows how to use the high level consumer. > bin/kafka-console-consumer. Custom Partitioner 구현한 예제는 따로 블로깅하도록 하겠습니다 ^^ Kafka 소개 Kafka란?. Kafka employs a dumb broker and uses smart consumers to read its buffer. sh --bootstrap-server BootstrapBrokerString--consumer. In this post I’ll explain my experience writing a Kafka consumer that wasn’t finding any messages when using consumer groups. Apache Kafka 0. Change the group id and Kafka will tell the consumer to start over with reading records from the beginning or the end according to the AUTO_OFFSET_RESET_CONFIG policy bellow. reset” is passed into the internally used KafkaConsumer as a means to define start position, but there’s work to further “de-couple” this so that respecting existing offsets in Kafka is merely one of the possible ways to define start position for the consumer, and that Flink isn’t depending on them in any way. For instance, if Kafka is configured to keep messages for a day and a consumer is down for a period of longer than a day, the consumer will lose messages. Consumer groups allow a group of machines or processes to coordinate access to a list of topics, distributing the load among the consumers. The @Before will initialize the MockConsumer before each test. Easy enough. From a consumer perspective the bridge is much more complex due to the nature of how consuming messages from Apache Kafka works in relation to consumer groups and partition rebalancing. consumer: A reference to the Kafka Consumer object. The Kafka consumer starts at the largest offset by default from when the consumer group is created. Editor's Note: If you're interested in learning more about Apache Kafka, be sure to read the free O'Reilly book, "New Designs Using Apache Kafka and MapR Streams". In the above image, we can see the Producer, Consumer, and Topic. Enabling security is simply a matter of configuration, no code changes are required. To enable the Kafka storage plugin, enter the following URL in the address bar of your browser to access the Storage page in the Drill Web UI:. Apache Kafka – Quick Start Guide. KafkaInboundEP1 is used to consume the message from specific topic partition 1 from server1 and KafkaaInboundEP2 is used to consume the message from specific topic partition 2 from server1. Kafka consumer internal structure is divided as we can see on the following diagram:. What is a Kafka Consumer ? A Consumer is an application that reads data from Kafka Topics. Spark Streaming + Kafka Integration Guide (Kafka broker version 0. ms' to a lower timeframe. Change the group id and Kafka will tell the consumer to start over with reading records from the beginning or the end according to the AUTO_OFFSET_RESET_CONFIG policy bellow. CSharpClient-for-Kafka. Kafka: Consumer and Consumer Groups. Apache Kafka - Simple Producer Example - Let us create an application for publishing and consuming messages using a Java client. KafkaConsumer class for reading messages from Kafka This is the main entry point for reading data from Kafka. sh –zookeeper localhost:2181 –topic “hadoop” –from-beginning Below is the screenshot of the Consumer console with the tweets. Apache Kafka in a nutshell Blogginlägg • Feb 05, 2019 09:51 CET. Debezium is a CDC tool that can stream changes from MySQL, MongoDB, and PostgreSQL into Kafka, using Kafka Connect. KafkaConsumer class with a set of properties, that looks like: consumer = new KafkaConsumer(properties); In this example, the properties are externalized in a file, with the following entries:. Consumer group. Overview: In the previous article, we had discussed the basic terminologies of Kafka and created local development infrastructure using docker-compose. CSharpClient-for-Kafka. Kafka Connect Vs Kafka Consumer In the next article we will learn how to implement a Kafka Producer and Consumer using Spring for Kafka. , “*TopicA” to consume from the source cluster and continue consuming from the target cluster after failover. /kafka-console-consumer. `bin/kafka-console-consumer. kafka-console-consumer --bootstrap-server 127. sh --bootstrap-server BootstrapBrokerString--consumer. In Kafka, it’s the responsibility of the consumer to manage the offsets: they can be written back to Kafka to a special topic, or stored entirely on the consumer side. Kafka provides a nice system to accomplish this: we can embed a Kafka producer (the messaging publishing API) in our user-facing service and publish our data to a Kafka topic with very little overhead. Setting this value to earliest will cause the consumer to fetch records from the beginning of offset i. Don't assume that offset 0 is the beginning offset, since messages age out of the log over time. 0 bin/kafka-console-consumer. sh--bootstrap-server localhost:9092--topic Posts--from-beginning 1. When the jobs to process the data are launched, Kafka's simple consumer API is used to read the defined ranges of offsets from Kafka (similar to read files from a file system). Over time we came to realize many of the limitations of these APIs. GraalVM installed if you want to run in native mode. "This is only the beginning for Guides - in the near future, travelers will be able to search within Guides for. Prefer to use the deserializing consumer Consumer where possible. get_simple_consumer (consumer_group = "mygroup", auto_offset_reset = OffsetType. If you want to process a topic from its beginning, you can simple start a new consumer group (i. Connect to Apache Kafka from Python using SSL be passed as argument of the constructor of the consumer and (TOPIC, 0)]) consumer. You can use the Kafka console consumer tool with IBM Event Streams. OffsetRequest. Together, you can use Apache Spark and Kafka to transform and augment real-time data read from Apache Kafka and integrate data read from Kafka with information stored in other systems. You created a Kafka Consumer that uses the topic to receive messages. During development & testing of Kafka consumers you may need to reset the current offset for a consumer so that the consumer can start from the first message. Logstash instances by default form a single logical group to subscribe to Kafka topics Each Logstash Kafka consumer can run multiple threads to increase read throughput. hydra --from-beginning. If you want to set up a test POC Kafka server please read this 15 minutes Kafka setup in 5 steps tutorial. Note: The Confluent Kafka Go client is safe for concurrent use. The first parameter is the name of your consumer group, the second is a flag to set auto commit and the last parameter is the EmbeddedKafkaBroker instance. We start by configuring the BatchListener. Developed custom APIs using Scala for handling certain file operations in Spark. Conclusion. kafkacat provides two modes, consumer and producer. sh --zookeeper localhost:2181 --topic test --from-beginning This gives following three lines as output: This is first message This is second message This is third message This reads the messages from the topic ‘test’ by connecting to the Kafka cluster through the ZooKeeper at port 2181. Repeat 1 to check if the reset is successful; Note. You can send data from Kafka to Arm Treasure Data, using the Fluentd consumer for Kafka. This allows Kafka to be, in essence, a replicated append-only log, which is easier to scale than a “stateful” message broker. In this article we'll see how to set it up and examine the format of the data. EARLIEST, reset_offset_on_start = False). In most use cases the consumer will simply consume records from beginning to end, periodically committing its position (either automatically or manually). In order to configure this type of consumer in Kafka Clients, follow these steps: First, set 'enable. The fraud detector will not be a plain consumer, though. sh --zookeeper localhost:2181 \ --topic earth \ --from-beginning \ --consumer. 8 Direct Stream approach. , “*TopicA” to consume from the source cluster and continue consuming from the target cluster after failover. 1:9092 --topic first_topic --from-beginning --partition 0 Show all the data from the beginning for one time but next time if this command executed it will only show the recently added message. Conclusion. I then set the “zookeeper. Pass message data to kafka-console-producer via STDIN; kafka-console-consumer takes max 10 messages from the beginning, so it won't block waiting for new messages. Apache Kafka – Quick Start Guide. Kafka is an open source tool that is a distributed streaming platform mainly used for consuming and producing records in real-time (similar to a messaging system) while being fault tolerant when configured in a cluster. What is a Kafka Consumer ? A Consumer is an application that reads data from Kafka Topics. You can also concurrently run the writing and reading program in order to send data from the TaxiRide Cleansing program through Kafka to the Popular Place program. pollTimeoutMs (consumer) The timeout used when polling the KafkaConsumer. Further, we have learned Producer API, Producer class, public void close. We will understand properties that we need to set while creating Consumer and how to handle topic offset to read messages from the beginning of the topic or just the latest messages. 1) Start a consumer from the beginning of the log kafka-console-consumer --bootstrap-server localhost:9092 --topic my-topic --from-beginning 2) Consume 1 message kafka-console-consumer --bootstrap-server localhost:9092 --topic my-topic --max-messages 1 3) Consume 1 message from __consumer_offsets. confluent-kafka; librdkafka 기반; installation. Kafka is an open-source stream-processing software platform written in Scala and Java. Getting Started with Apache Kafka for the Baffled, Part 1 Jun 16 2015 in Programming. 9 or higher, please move to using the confluent-kafka-dotnet client library. Setting this to a higher value can reduce CPU utilization due to less frequent polling, but introduces latency in writing batches to the channel. If you want to read messages from the beginning of topic then you can use ‘–from-beginning’ argument with the console command. We have covered most of the basics of Kafka and explored Kafka producers in detail. zkhosts=”kafka-manager-zookeeper:2181″ # this is default value, change it to point to zk instance. I'll show you how to pull Landoop's Kafka image from Docker Hub, run it and how you can get started with Kafka. We will produce messages to the just created topic my-kafka-topic; Creating a Kafka Consumer. Apache Kafka Tutorial - Learn about Apache Kafka Consumer with Example Java Application working as a Kafka consumer. Kafka provides a nice system to accomplish this: we can embed a Kafka producer (the messaging publishing API) in our user-facing service and publish our data to a Kafka topic with very little overhead. If you haven’t setup the consumer yet follow this tutorial. Kafka CLI hands-on Here is a series of exercises to try some common Kafka operations by using CLI (command line interface). pollTimeoutMs (consumer) The timeout used when polling the KafkaConsumer. 1439686893722, Shirley is awesome. id) and set auto. The producer and consumer components in this case are your own implementations of kafka-console-producer. In yet another shell, run this to start a Kafka consumer: bin/kafka-consumer. This offset is stored based on the consumer group name provided to Kafka at the beginning of the process. Setting up Client cert mutual authentication in a kafka hdf cluster Note, If keytool not found on path, do this first for your local instalation of java. Flink's Kafka consumer is called FlinkKafkaConsumer08 (or 09 for Kafka 0. Kafka also has a command line consumer that will dump out messages to standard output. sh --bootstrap-server localhost:9092 --topic kafka-example-topic --from-beginning. bat --bootstrap-server localhost:9092 --topic test --from-beginning All I want to do is to fetch messages from the time the client gets connected to the Apache server, not from the beginning. Many times, requirements are not clear at the beginning of design and implementation, we must use open closed principle to implement initial design and slowly if requirements change, it becomes easy to add them in design. So, if you are using Kafka 0. The producer and consumer components in this case are your own implementations of kafka-console-producer. Consume the above message using Kafka console consumer. Basically, Kafka producers write to the Topic and consumers read from the Topic. ExportZkOffsets$) Export consumer offsets to an output file. Refer to the steps in this module: Run NiFi in the Trucking IoT Demo, then you will be ready to explore Kafka. Welcome folks,Read about microservices/ event-driven architecture first. Kafka consumer internal structure is divided as we can see on the following diagram:. accepts ("delete-consumer-offsets", "If specified, the. py to see a way of installing Kafka for development. I am not showing the code for my Kafka Producer in this blog, as the blog is about Kafka Consumers. Filled with real-world use cases and scenarios, this book probes Kafka's most common use cases, ranging from simple logging through managing streaming data systems for message routing, analytics, and more. High-level consumer. Start both and then setup local Producer and Consumer with a first stab at using topics including --from-beginning option. Each message from the broker contains the topic that the message was sent to, as well as the message, key, offset, and partition. Netflix has ruled the streaming video world for years. We will implement a simple example to send a message to Apache Kafka using Spring Boot Spring Boot + Apache Kafka Hello World Example In this post we will integrate Spring Boot and Apache Kafka instance. Apache Kafka & Storm. Consumer group. kafka-python no broker available with kafka on localhost. This is all that is required once you have setup the consumer. A push model would take control away from the Kafka Consumer. "This is only the beginning for Guides - in the near future, travelers will be able to search within Guides for. About six years ago, LinkedIn was facing some problem in their messaging platform and they decided to redesign the infrastructure; that way, they introduced Kafka. I then set the “zookeeper. /kafka-console-consumer. Configuring Kafka Clients. accepts ("property"). If you want data that is older you have to. In most use cases the consumer will simply consume records from beginning to end, periodically committing its position (either automatically or manually). This will send This is the First Message I am sending Message to the Kafka consumer. It is very fast and reliable. How to read from a Kafka topic from the beginning. The Kafka consumer starts at the largest offset by default from when the consumer group is created. sh that allows one to view and manipulate consumer group state. Run a build. Components of Kafka are : Kafka saves messages in a disk and allows subscribers to read from it. consumer: A reference to the Kafka Consumer object. In the “Monitor” page, a new job is generated; Wait it 100% finished. What is a Kafka Consumer ? A Consumer is an application that reads data from Kafka Topics. sh --bootstrap-server localhost:9092 --topic test --consumer. We should also provide a group id which will be used to hold offsets so we won't always read the whole data from the beginning. This is all that is required once you have setup the consumer. sh --bootstrap-server localhost:9091 --topic topic-devinline-1 --from-beginning Hello,Message-1 Hello,Message-2 Hello,Message-3. sh --bootstrap-server localhost:9092 --topic myFirstTopic --from-beginning Run the above command in a new tab and you should be able to see all the messages that were produced before:. So I will focus in options available in Kafka Consumer. Additionally, Kafka provides a script to manually allow developers to create a topic on their cluster. The Kafka brokers are an important part of the puzzle, but do not provide the Consumer Group behavior directly. The following configuration can be used for this use case. 9 or higher, please move to using the confluent-kafka-dotnet client library. As mentioned at the beginning of this post, we’re going to use the Kafka Connect Neo4j Sink Plugin to get the data from Kafka into Neo4j. Although kafka guarantees ordering within a partition, kafka-node's HighLevelConsumer' resembles a sort of firehose, emitting messages as soon as they arrive, regardless of how fast the application is able to process them. Question by Kennon Rodrigues Jun 01, 2018 at 11:27 AM Kafka Atlas hdp-2. bin/kafka-console-consumer. In Kafka, there is built-in support for this via offset commits. In the producer stream, type some messages. Kafka in Action is a practical, hands-on guide to building Kafka-based data pipelines. Kafka를 주제로 발표했던 자료 정리한 내용입니다. Next time you start this consumer it won’t even use that auto. ~/ kafka /bin/kafka-console-consumer. sh that allows one to view and manipulate consumer group state. Apache Kafka is a powerful message broker service. RangeAssignor. Recode - Peter Kafka. This allows you to see all messages from all suite products and to consume these messages with any of the existing Kafka client implementations. sh --bootstrap-server --topic --from-beginning --consumer. I hope you are following this training from the beginning. If you haven't setup the consumer yet follow this tutorial. sh --bootstrap-server localhost:9093 --topic my-kafka-topic --from-beginning The bootstrap-server can be any one of the brokers in the cluster, and the topic should be the same as the topic under which you producers inserted data into the cluster. sh --bootstrap. 8% in Q1 2019 to $6. Kafka and Zookeeper get started Mon Goose Start both and then setup local Producer and Consumer with a first stab at using topics including --from-beginning option. The examples in this repository demonstrate how to use the Kafka Consumer, Producer, and Streaming APIs with a Kafka on HDInsight cluster. Because there are no committed offsets for a new group, auto offset reset will trigger and the topic will be consumed from its beginning. Committed offsets of input topics: Internally, Kafka Streams leverages Kafka's consumer client to read a topic and to commit offsets of processed messages in regular intervals (see commit. Apache Kafka is creating a lot of buzz these days. id configuration which is equivalent to group. bin/kafka-console-consumer. sh –zookeeper localhost:2181 –topic “hadoop” –from-beginning Below is the screenshot of the Consumer console with the tweets. A) Kafka also has a command line consumer that will dump out messages to standard output. You also learn about Kafka topics, subscribers, and consumers. See Pausing and Resuming Listener Containers for more information. The easiest way to do this is by using the Kafka client tools included in the Kafka bin directory because this will work regardless of the Kafka client which you are using. Spark Streaming + Kafka Integration Guide (Kafka broker version 0. This document covers the protocol implemented in Kafka 0. This means that a consumer can pick the point in time when it wants to start consuming. They employ numerous Private Lenders Hard Cash Personal tools and tips for optimizing your site and transform your websites' search engine rank. Apache Kafka is creating a lot of buzz these days. The -b option specifies the Kafka broker to talk to and the -t option specifies the topic to produce to. ZooKeeper does not scale extremely well (especially for writes) when there are a large number of offsets (i. sh --bootstrap-server localhost:9092 --topic myFirstTopic --from-beginning Run the above command in a new tab and you should be able to see all the messages that were produced before:. sh --bootstrap-server localhost:9092 --from-beginning --topic Demo This is a test of the Emergency Broadcast System. Basically, Kafka producers write to the Topic and consumers read from the Topic. sh --bootstrap-server localhost:9092 --topic test --from-beginning If you run, it will dump all the messages from the beginning till now. 3 Integrating Kafka with NodeJS Let's create a API in NodeJS which will act as a Producer to Kafka. Think a bout product from the beginning, but do. In the Kafka Consumer dialog, I specified the topic name as “test” to match what I did during the Kafka Quick Start. A push model would take control away from the Kafka Consumer. confluent-kafka; librdkafka 기반; installation. EarliestTime() finds the beginning of the data in the logs and starts streaming from there, kafka. reset” is passed into the internally used KafkaConsumer as a means to define start position, but there’s work to further “de-couple” this so that respecting existing offsets in Kafka is merely one of the possible ways to define start position for the consumer, and that Flink isn’t depending on them in any way. You can use the Kafka console consumer tool with IBM Event Streams. sh with Aiven Kafka requires that you first create keystore and truststore as per instructions in Getting started with Kafka guide under Java keystore management. MySQL CDC with Apache Kafka and Debezium Architecture Overview. commit' to true. In this post I’d like to give an example of how to consume messages from a kafka topic and especially how to use the method consumer. Internally, MirrorMaker2 uses the Kafka Connect framework which in turn use the Kafka high level consumer to read data from Kafka. id) and set auto. You start seeing the messages you entered earlier when you used the console producer command. pollTimeoutMs (consumer) The timeout used when polling the KafkaConsumer. “Apache Kafka” Jan 15, 2017. Beginning Apache Kafka with VirtualBox Ubuntu server & Windows Java Kafka client After reading a few articles like this one demonstarting significant performance advantages of Kafa message brokers vs older RabbitMQ and AtciveMQ solutions I decided to give Kafka a try with the new project I am currently playing with. As a result, we’ll see the system, Kafka Broker, Kafka Consumer, and Kafka Producer metrics on our dashboard on Grafana side. So, if you are using Kafka 0. Basically, Kafka producers write to the Topic and consumers read from the Topic. Consumer groups __must have__ unique group ids within the cluster, from a kafka broker perspective. Kafka is an open-source stream-processing software platform written in Scala and Java. Before proceeding further, let’s make sure we understand some of the important terminologies related to Kafka. Reset Offset for a topic. sh --bootstrap. Setting up Client cert mutual authentication in a kafka hdf cluster Note, If keytool not found on path, do this first for your local instalation of java. ms is set to 10, so when Flume polls Kafka for new data, it waits no more than 10 ms for the data to be available. In the Kafka Consumer dialog, I specified the topic name as “test” to match what I did during the Kafka Quick Start. Apache Kafka quick start is very well documented to start on Linux machine. link to the read articleSo let's make a pub/sub program using Kafka and Node. Kafka Connect is a framework included in Apache Kafka that integrates Kafka with other systems. EarliestTime() finds the beginning of the data in the logs and starts streaming from there, kafka. Then we will create three scripts to start these servers up using these properties, and then start the servers. Kafka String Consumer To consume data from Kafka with Flink we need to provide a topic and a Kafka address. Confluent Platform includes the Java consumer shipped with Apache Kafka®. , choose an unused group. / bin / kafka-console-consumer--bootstrap-server localhost: 9092--topic START_TRIP_COUNT_BY_STATIONS--from-beginning From the above console output, it is evident that the trip counts are updated and added to the topic for each day when producing the message. In this post, we define consumer offset and outline the factors that determine the offset. I hope you are following this training from the beginning. ~/ kafka /bin/kafka-console-consumer. For example, my first application, but you can name it whatever you want and press enter. 3 Integrating Kafka with NodeJS Let's create a API in NodeJS which will act as a Producer to Kafka. OffsetRequest. 1, and a Kafka topic that provides all Information Server events as Kafka messages. As explained in a previous post. sh it will register itself with a different name with Zookeeper and so you will always get messages from now onwards unless you explicitly give an offset. Have the consumer initially read all records and insert them, in order, into an in-memory cache. This client class contains logic to read user input from the console and send that input as a message to the Kafka server. The best Kafka library for node. So in kafka, feeds of messages are stored in categories called topics. Overview: In the previous article, we had discussed the basic terminologies of Kafka and created local development infrastructure using docker-compose. These are the most commonly used Kafka commands for running producer and consumer from command line terminal. The high-level consumer stores the last offset read from a specific partition in ZooKeeper. For example, we can set up a cluster of more than one node, can create multiple partitions. 0 or higher) The Spark Streaming integration for Kafka 0. Below are. This is a quick tutorial on how to seek to beginning using a Kafka consumer. It is meant to give a readable guide to the protocol that covers the available requests, their binary format, and the proper way to make use of them to implement a client. Don't assume that offset 0 is the beginning offset, since messages age out of the log over time. KafkaConsumer class with a set of properties, that looks like: consumer = new KafkaConsumer(properties); In this example, the properties are externalized in a file, with the following entries:. Kafka Streams API only support to go back to the earliest offset of the input topics, and is well explained by Matthias J. ; AutoOffsetReset: Kafka lets you consume topic records in any order, you can consume from the beginning or. Kafka - (Consumer) Offset - If specified, the consumer path in zookeeper is deleted when starting up --from-beginning Start with the earliest message present in the log rather than the latest message. --from-beginning: If the consumer does not already have an established offset to consume from, start with the earliest message present in the log rather than the latest message. MAX_VALUE) means to the end position on Kafka topic. sh --bootstrap-server localhost:9092 --topic test --from-beginning If you run, it will dump all the messages from the beginning till now. 8 billion, while the worldwide enterprise and service provider (SP) router m. It is a streaming application. Apache Maven 3. Kafka Consumer API support go back to the beginning of the topic, go back to a specific offset, and go back to a specific offset by timestamps. If you want to read messages from the beginning of topic then you can use ‘–from-beginning’ argument with the console command. key=true null my test message 1 null my test message 2 key1 my test message 1 key2 my test message 2. consumer: A reference to the Kafka Consumer object. Intro Producers / Consumers help to send / receive message to / from Kafka SASL is used to provide authentication and SSL for encryption JAAS config files are used to read kerberos ticket and authenticate as a part of SASL Kafka Version used in this article :0. consumer = consumer; this. bin/kafka-console-consumer.