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Flink watermarks in 90 secs and hybrid Kafka architecture

September 7, 2023

Hello everyone! Hope your September is off to a solid start! This week our roundup is stuffed with a variety of resources: a video to help you differentiate between different terms in the Kafka landscape, a 90-second explanation of Flink watermarks, a new whitepaper on Kora, a blog on Flink for developers already familiar with Kafka, and a way to manage your Confluent CLI plugins. Enjoy!

Apache Kafka® Resources:

Apache Flink® Resources:

Terminal Tip of the Week:

What if you want to list metadata from your Kafka cluster, topics, partitions, replicas and in-sync replicas?

You can run a command with the -L and -J flags using kcat:

kcat -b mybroker -L -J

-L is for list mode, and -J ensures JSON output.

The output will look like the following (‘replicas’ and ‘isrs’ listing the brokers on which the replicas and in-sync-replicas live):

 6 topics:
  topic "pksqls-ddw45-processing-log" with 8 partitions:
    partition 0, leader 4, replicas: 4,9,2, isrs: 9,4,2
    partition 1, leader 8, replicas: 8,10,0, isrs: 0,10,8
    partition 2, leader 6, replicas: 6,11,4, isrs: 6,4,11
    partition 3, leader 7, replicas: 7,3,8, isrs: 3,7,8

Links From Around the Web:

  • Make a fun bracelet with an old MacBook keyboard
  • A foraging map in case you’d like to pick up some free fruit or vegetables
  • Learn about parameter expansion in bash from Julia Evans’s zine

In Other News:

We’ve got 3 in-person Kafka meetups happening across the world this month!

  • In-Person Meetup in Vienna (Sep 26th): Thinking In Events/Kafka and System of Records
  • In-Person Meetup in Frankfurt (Sep 26th): Apache Flink® For Apache Kafka® Developers
  • In-Person Meetup in St Louis (Sep 20th): Yes, You CAN Do Event Sourcing With Kafka (With a Little Help)
  • Current 2023 is happening soon in San Jose, Sep 26-27! Network with data streaming experts from across the globe and learn new approaches to using Kafka, Flink, and other streaming technologies in the breakout sessions. Get a sneak peek at the content in this video.

By the way…

We hope you enjoyed our curated assortment of resources! If you’d like to provide feedback, suggest ideas for content you’d like to see, or you want to submit your own resource for consideration, send us an email at!

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P.S. If you want to learn more about Kafka or Confluent Cloud, visit our developer site at Confluent Developer.

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