I am newbie in Kafka. I want to consume remote kafka message in shell script. Basically I have linux machine where I cannot run any web server (some strange reasons) only thing I can do is use crontab/shell script to listen for kafka message which is hosted remotely. Is it possible to write simple shell script which will consume kafka message, parse it and take corresponding action.
kafka clients are available in multiple languages. you can use any client, you don't need any web server or browser for it.
you may use shell script for consuming message & parsing but that script have to use any kafka client provided here because currently there is no client written in pure shell script.
Kafka has provided kafka client console producer and consumer, you can use that as well.
bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic test --from-beginning
follow the document properly.
You could also use the tool kafkacat which is documented for example here.
This is a very powerful and fast tool to read data out of Kafka from the console and is open source: https://github.com/edenhill/kafkacat.
Many exmples are provided on GitHub and one example is shown below:
kafkacat -C -b mybroker -t mytopic
Related
I have produce message using Kafka producer in java application and I had consumed message from Kafka Server smoothly..
But suddenly I cant run the command '''kafka-console-consumer.bat''' in the command prompt. It doesn't display any error message..
I have tried to consume message from the Kafka server through the command '''kafka-console-consumer.bat --bootstrap-server localhost:9092 --from-beginning --topic student-details''' where the '''student-details''' is the Topic name
But the command doesn't working.. Is there any alternative way to consume message
The alternative is to write code for a consumer, or use any other tool available. I prefer kcat on the CLI.
To debug your problem, you could edit Kafka's log4j.properties to increase the log level of the consumer.
Or, depending on how much time elapsed between "now", and "working perfectly", your topic is empty.
I am using apache kafka in 1st server and apache zookeeper in 2nd server.
I want to have kafka connect service in other server.Is it possible to use a standalone service. I need to have apache kafka connect or confluent kafka connect
There is no such thing as "Confluent Kafka (Connect)"
Kafka Connect is Apache 2.0 Licensed and released as part of Apache Kafka. Confluent and other vendors write plugins (free, or enterprise-licensed) for Kafka Connect.
Yes, it it recommended to run Connect as a separate set of servers than either then brokers or zookeepers. In order to run it, you will need to download all of Kafka, then use bin/connect-distributed, or you can run it via Docker containers.
You can easily run a Kafka Connect Standalone (Single Process) service from any server, provided you have configured both connector and workers properties correctly.
A gist of it here, if you are interested.
In standalone mode all work is performed in a single process. It is easy to setup and get started but it does not benefit from some of the features of Kafka Connect such as fault tolerance.
You can start a standalone process with the following command:
bin/connect-standalone.sh config/connect-standalone.properties connector1.properties connector2.properties
The first parameter is the configuration for the worker, it includes connection parameters, serialization format, and how frequently to commit offsets.
All workers (both standalone and distributed) require a few configs:
bootstrap.servers - List of Kafka servers used to bootstrap connections to Kafka
Key/Value.converter - Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka.
offset.storage.file.filename - File to store offset data
A Simple standalone connecter (Import Data from a file into KAFKA)
kafka-topics --create --zookeeper localhost:2181 --replication-factor 2 --partitions 10 --topic connect-test to create a topic called connect-test with 10 partitions (Up to us) and replication factor of 2
To start a standalone Kafka Connector, we need following three configuration files located under C:\kafka_2.11-1.1.0\config. Update these configuration files as following
connect-standalone.properties
offset.storage.file.filename=C:/kafka_2.11-1.1.0/connectConfig/connect.offsets
connect-file-source.properties
file=C:/kafka/Workspace/kafka.txt
connect-file-sink.properties
file=test.sink.txt
Execute the following command
Connect-standalone.bat C:\kafka_2.11-1.1.0\config\connect-standalone.properties C:\kafka_2.11-1.1.0\config\connect-file-source.properties C:\kafka_2.11-1.1.0\config\connect-file-sink.properties
Once the Connector is started, initially the data in kafka.txt would be synced to test.sync.txt and the data is published to the Kafka Topic named, connect-test. Then any changes to the kafka.txt file would be synced to test.sync.txt and published to connect-test topic.
Create a Consumer
kafka-console-consumer.bat --bootstrap-server localhost:9096 --topic connect-test --from-beginning
CLI Output
kafka-console-consumer --bootstrap-server localhost:9096 --topic connect-test --from-beginning
{"schema":{"type":"string","optional":false},"payload":"This is the stream data for the KAFKA Connector"}
Add a new line into “Consuming the events now” into the kafka.txt
CLI Output
kafka-console-consumer --bootstrap-server localhost:9096 --topic connect-test --from-beginning
{"schema":{"type":"string","optional":false},"payload":"This is the stream data for the KAFKA Connector"}
{"schema":{"type":"string","optional":false},"payload":"Consuming the events now"}
I am trying to achieve cronjob which sends a Kafka message once a day. Kafka broker is running on remote instance.
I am currently accomplishing this by installing entire Kafka package, and then having cronjob call a script which look like:
less msg.txt | <kafka_path>/bin/kafka-console-producer.sh --broker-list <AWS_INSTANCE_IP> --topic <topic> --producer.config <property.file>
Is it possible to isolate the Jar(s) kafka-console-producer.sh require so I can do this without dragging in rest of the stuff in kafka directory (i.e broker related stuff) into my system? Since they aren't required. Is there some pre-existing solution for this?
Thank you.
If you must use JVM solutions, you'd have to build your own tooling with a dependency on org.apache.kafka:kafka-clients
If you can use other solutions, kafkacat is its own standalone, portable script.
I am working on a existing project and using kafka to fetch some data from DB(for generating reports). I have some questions. Which may sound silly to many(Sorry for that). I am mentioning the steps which I have performed till now.
Installed Confluent
Started Zookeeper, Kafka and Schema Registry
I had downloaded MySql connectors jars and copied to kafka-connect-jdbc
Then made a mysql properties file with connection url, topic-prefix etc.
The I started the mysql connector using this command
bin/connect-standalone etc/schema-registry/connect-avro-standalone.properties etc/kafka-connect-jdbc/source-quickstart-mysql.properties
After this if I run the avro consumer command in terminal using this command
bin/kafka-avro-console-consumer --topic mysql-01 --bootstrap-server localhost:9092 --from-beginning
it gives data succesfully.
Now, the problem and confusion.
I want to get the same data by using Spring Boot.
I am writing code only for consumer. Do I need a Producer here??(As per my understanding goes, I have data already in my topic, I just need to fetch that)
I have made an avro schema for that as well. It gets deserialized as well but I don't get the data.
The data which get printed in terminal is:
{"cust_code":27,"cust_description":{"string":"Endline survey completed"}}
The data in Spring Boot console is:
{"cust_code": "cust_description":{"string":""}}
I am using kafka 1.0.0V In my project. From yesterday on wards. I am unable to listen Messages from command line . In the same time I am able to listen the messages from Kafka tool. In the same time My applications are also not consuming the data. Is there any issue in kafka.
This is the command i am using to consume the messages
/usr/hdp/2.6.0.3-8/kafka/bin/kafka-console-consumer.sh --bootstrap-server hostname:6667 --topic test --from-beginning
topic create,describe,produce command are working from commandline