How to start Apache Kafka

Apache Kafka is an open-source for distributed streaming system. We can use it as a Messaging System, a Storage System or Stream Processing. So in the tutorial, JavaSampleApproach will show you the first step to quick start with Apache Kafka.

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How to start Spring Apache Kafka Application with SpringBoot Auto-Configuration

1. Download Apache Kafka

Go to the download page, download file Scala 2.12 – kafka_2.12-0.10.2.1.tgz (asc, md5)

Apache kafka Quick start- download source

We will get a .tar file, then un-tar it, we have folder kafka_2.12-0.10.2.1:

Apache kafka folder

cd to .\kafka_2.12-0.10.2.1\bin:

Apache kafka Quick start- unix bin

All files .sh under folder .\kafka_2.12-0.10.2.1\bin is used to setup Apache Kafka in Unix-based environment.

cd to .\kafka_2.12-0.10.2.1\bin\windows:

Apache kafka Quick start- windows

All files .bat under folder .\kafka_2.12-0.10.2.1\bin\windows is used to setup Apache Kafka in Windows platforms.

2. Start a Kafka server

Apache Kafka uses ZooKeeper as a centralized service, so we need to start a ZooKeeper.

-> Open a cmd, cd to .\kafka_2.12-0.10.2.1:

– Unix-based

> bin/zookeeper-server-start.sh config/zookeeper.properties

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\zookeeper-server-start.bat .\config\zookeeper.properties

-> Logs:
[2017-06-06 17:59:52,636] INFO Reading configuration from: .\config\zookeeper.properties
...

Start the Apache Kafka server.

-> Open a new cmd, cd to .\kafka_2.12-0.10.2.1:

– Unix-based

> bin/kafka-server-start.sh config/server.properties

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-server-start.bat .\config\server.properties

-> Logs:
[2017-06-06 18:06:53,365] INFO starting (kafka.server.KafkaServer)
[2017-06-06 18:06:53,367] INFO Connecting to zookeeper on localhost:2181 (kafka.server.KafkaServer)
[2017-06-06 18:06:53,379] INFO Starting ZkClient event thread. (org.I0Itec.zkclient.ZkEventThread)
...

3. Create a Kafka Topic

Setup a topic with name jsa-test, that has only one partition & one replica.

-> Open a new cmd and cd to .\kafka_2.12-0.10.2.1:

– Unix-based

> bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic jsa-test

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-topics.bat --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic jsa-test

-> Logs:
Created topic "jsa-test".

List out the topics:

– Unix-based

> bin/kafka-topics.sh --list --zookeeper localhost:2181
jsa-test

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-topics.bat --list --zookeeper localhost:2181
jsa-test

4. Use Kafka Producer to send messages

Use Kafka command line client to send messages to Kafka topic.

– Unix-based

> bin/kafka-console-producer.sh --broker-list localhost:9092 --topic jsa-test
Hello World!
This is a message to jsa-test topic!

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-console-producer.bat --broker-list localhost:9092 --topic jsa-test
Hello World!
This is a message to jsa-test topic!

5. Start a Kafka consumer

Use Kafka command line consumer to print out messages on standard output.

– Unix-based

> bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic jsa-test --from-beginning

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-console-consumer.bat --bootstrap-server localhost:9092 --topic jsa-test --from-beginning

-> Results:

Hello World!
This is a message to jsa-test topic!

6. Create a multi-broker cluster

Up to now, we had setup the Kafka cluster with single node. Now we go to next step: setup 2 new nodes for the Kafka cluster.

6.1 Create a config file for new brokers

– Unix-based

> cp config/server.properties config/server-1.properties
> cp config/server.properties config/server-2.properties

Edit new files as below:

config/server-1.properties:
    broker.id=1
    listeners=PLAINTEXT://:9093
    log.dirs=/tmp/kafka-logs-1

config/server-2.properties:
    broker.id=2
    listeners=PLAINTEXT://:9094
    log.dirs=/tmp/kafka-logs-2

– Windows

C:\kafka_2.12-0.10.2.1>copy .\config\server.properties .\config\server-1.properties
        1 file(s) copied.

C:\kafka_2.12-0.10.2.1>copy .\config\server.properties .\config\server-2.properties
        1 file(s) copied.

Edit new files {server-1.properties, server-2.properties} as below:

config/server-1.properties:
    broker.id=1
    listeners=PLAINTEXT://:9093
    log.dirs=kafka-logs-1

config/server-2.properties:
    broker.id=2
    listeners=PLAINTEXT://:9094
    log.dirs=kafka-logs-2
6.2 Start new nodes

– Unix-based

> bin/kafka-server-start.sh config/server-1.properties &
...
> bin/kafka-server-start.sh config/server-2.properties &
...

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-server-start.bat .\config\server-1.properties &
...

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-server-start.bat .\config\server-2.properties &
...
6.3 Create a new topic for replication

– Unix-based

> bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 3 --partitions 1 --topic jsa-replicated-topic

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-topics.bat --create --zookeeper localhost:2181 --replication-factor 3 --partitions 1 --topic jsa-replicated-topic
Created topic "jsa-replicated-topic".

Check the replicated-topic by describe topics command:

– Unix-based

> bin/kafka-topics.sh --describe --zookeeper localhost:2181 --topic jsa-replicated-topic

– Windows

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-topics.bat --describe --zookeeper localhost:2181 --topic jsa-replicated-topic

-> Results:

Topic:jsa-replicated-topic      PartitionCount:1        ReplicationFactor:3     Configs:
        Topic: jsa-replicated-topic     Partition: 0    Leader: 2       Replicas: 2,0,1 Isr: 2,0,1

The first line gives a summary of all the partitions. Each additional line gives information about one partition.

leader is the node responsible for all reads and writes for the given partition.
replicas is the list of nodes that replicate the log for this partition regardless of whether they are the leader or even if they are currently alive.
isr is the set of “in-sync” replicas. This is the subset of the replicas list that is currently alive and caught-up to the leader.

6.4 Create a Producer and Consumer to replicated-topic

– Unix-based

> bin/kafka-console-producer.sh --broker-list localhost:9092 --topic jsa-replicated-topic
Message 1
Message 2
> bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --from-beginning --topic jsa-replicated-topic
Message 1
Message 2

– Window

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-console-producer.bat --broker-list localhost:9092 --topic jsa-replicated-topic
Message 1
Message 2
C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-console-consumer.bat --bootstrap-server localhost:9092 --from-beginning --topic jsa-replicated-topic
Message 1
Message 2
6.5 Fault-Tolerance

See again the topic description:

Topic:jsa-replicated-topic      PartitionCount:1        ReplicationFactor:3     Configs:
        Topic: jsa-replicated-topic     Partition: 0    Leader: 2       Replicas: 2,0,1 Isr: 2,0,1

Broker 2 is the leader. -> We will kill it by commandline:

– Unix-based

> ps aux | grep server-1.properties
435 ttys002    0:15.91 /System/Library/Frameworks/JavaVM.framework/Versions/1.8/Home/bin/java...
> kill -9 435

– Windows

> wmic process get processid,caption,commandline | find "java.exe" | find "server-2.properties"
java.exe   ... config\server-1.properties    422
> taskkill /pid 422 /f

Or We can use Ctr + C on cmd of Broker 2 to kill it.

See shutdown logs:

...

[2017-06-06 19:16:40,807] INFO Truncating log jsa-replicated-topic-0 to offset 2. (kafka.log.Log)
[2017-06-06 19:16:40,836] INFO [Kafka Server 2], Controlled shutdown succeeded (kafka.server.KafkaServer)
[2017-06-06 19:16:40,838] INFO [Socket Server on Broker 2], Shutting down (kafka.network.SocketServer)
[2017-06-06 19:16:40,844] INFO [Socket Server on Broker 2], Shutdown completed (kafka.network.SocketServer)
[2017-06-06 19:16:40,847] INFO [Kafka Request Handler on Broker 2], shutting down (kafka.server.KafkaRequestHandlerPool)
[2017-06-06 19:16:40,873] INFO [Kafka Request Handler on Broker 2], shut down completely (kafka.server.KafkaRequestHandlerPool)
[2017-06-06 19:16:40,877] INFO [ThrottledRequestReaper-Fetch], Shutting down (kafka.server.ClientQuotaManager$ThrottledRequestReaper)
[2017-06-06 19:16:41,864] INFO [ThrottledRequestReaper-Fetch], Stopped  (kafka.server.ClientQuotaManager$ThrottledRequestReaper)
[2017-06-06 19:16:41,864] INFO [ThrottledRequestReaper-Fetch], Shutdown completed (kafka.server.ClientQuotaManager$ThrottledRequestReaper)
[2017-06-06 19:16:41,866] INFO [ThrottledRequestReaper-Produce], Shutting down (kafka.server.ClientQuotaManager$ThrottledRequestReaper)
[2017-06-06 19:16:41,896] INFO [ThrottledRequestReaper-Produce], Stopped  (kafka.server.ClientQuotaManager$ThrottledRequestReaper)
[2017-06-06 19:16:41,896] INFO [ThrottledRequestReaper-Produce], Shutdown completed (kafka.server.ClientQuotaManager$ThrottledRequestReaper)
[2017-06-06 19:16:41,898] INFO [KafkaApi-2] Shutdown complete. (kafka.server.KafkaApis)

...

Again check description of replicated-topic:

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-topics.bat --describe --zookeeper localhost:2181 --topic jsa-replicated-topic
Topic:jsa-replicated-topic      PartitionCount:1        ReplicationFactor:3     Configs:
        Topic: jsa-replicated-topic     Partition: 0    Leader: 0       Replicas: 2,0,1 Isr: 0,1

-> Now the Leader is Broker 0. Broker 2 had been shutdown so in-sync list, so We just have 2 brokers {0, 1}.

Make a consumer for checking the available messages:

C:\kafka_2.12-0.10.2.1>.\bin\windows\kafka-console-consumer.bat --bootstrap-server localhost:9092 --from-beginning --topic jsa-replicated-topic
Message 1
Message 2

-> Kafka Fault-Tolerance works right! Now you can start development with Apache Kafka!



By grokonez | June 6, 2017.


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