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"Hello World" for Apache Kafka
playgroundcommand will start an Agent on
localhost, store all the data for the Agent in memory, and sign up for a temporary account for you to play around with.
Let's create a topic using the Apache Kafka client built-in to the WarpStream Agent. We're going to assume in this tutorial you're running the Agent as specified above on localhost, so we'll omit the arguments to specify the Kafka bootstrap URL.
warpstream kcmd --type create-topic --topic helloworld2
If you don't receive an error back, your request to create the topic succeeded.
Now let's write a record to the topic. The
kcmdtool writes records with a constant key of "hello", and we'll write two records with the payload of "
world" as our example (
,,) is the delimiter).
warpstream kcmd --type produce --topic helloworld2 --records "world,,world"
You should receive output in your terminal that looks something like this:
result: partition:0 offset:0 value:"world"
result: partition:0 offset:1 value:"world"
warpstream kcmd --type fetch --topic helloworld2 --offset 0
Now you should see your records you wrote previously printed to the console. The key is always "hello" and the value field is the same "world" string we wrote before. You can repeat the process of writing another record and running
kcmd --type fetchagain to read and write more records.
result: partition:0 offset:0 key:"hello" value:"world"
result: partition:0 offset:1 key:"hello" value:"world"
And that's it! You've successfully set up a WarpStream Agent Pool to power your Virtual Cluster, created a topic, and processed some data through it.
You can now move on to trying to create a real application which reads or writes from the topic, or connect your existing tools like Flink to WarpStream.