Posts Tagged ‘kafka’

You need two schemas to deserialize an Avro message… but which two?

Friday, November 17th, 2023

In this post, I want to talk about what happens when you use Avro to deserialize messages on a Kafka topic, why it actually needs two schemas, and what those schemas need to be.

I should start by pointing out that if you’re using a schema registry, you probably don’t need to worry about any of this. In fact, a TLDR for this whole post could be “You should be using a good schema registry and SerDes client“.

But, there are times where this may be difficult to do, so knowing how to set a deserializer up correctly is helpful. (Even if you’re doing the right thing and using a Schema Registry, it is still interesting to poke at some of the details and know what is happening.)

The key thing to understand is that to deserialize binary-encoded Avro data, you need a copy of the schema that was used to serialize the data in the first place [1].

This gets interesting after your topic has been around for a while, and you have messages using a mixture of schema versions on the topic. Maybe over the lifetime of your app, you’ve needed to add new fields to your messages a couple of times.

If you want a consumer application to be able to consume all of the messages on this topic, what does that mean?


Using IBM Event Automation with Amazon MSK

Wednesday, October 25th, 2023

Written with Chris Patmore

IBM Event Automation helps companies to accelerate their event-driven projects wherever businesses are on their journey. It provides multiple components (Event Streams, Event Endpoint Management, and Event Processing) which together lay the foundation of an event-driven architecture that can unlock the value of the streams of events that businesses have.

A key goal of Event Automation is to be composable. The three components can be used together, or they can each be used to extend and enhance an existing event-driven deployment.

Amazon MSK (Managed Streaming for Kafka) is a hosted, managed Kafka service available in Amazon Web Services. If a business has started their event-driven journey using MSK, then components from Event Automation can help to enhance this. This could be by offering management and governance of their MSK topics. And it could be by providing an intuitive low-code authoring canvas to process the events on their MSK topics.

Working with Amazon MSK is a nice example of the benefits of the composability of Event Automation, by helping businesses to get more value from their existing MSK topics.

In this blog post, we want to show a few different examples of where this can be done. For each example, we’ll provide a high-level diagram and description. We’ll also share a demonstration that we created to show it in action.


Connecting App Connect Enterprise to Event Endpoint Management

Friday, October 20th, 2023

Configuring IBM App Connect Enterprise to consume messages from Kafka topics in IBM Event Endpoint Management requires careful configuration. In this post, I’ll share the steps I use that help me to avoid missing any required values.

If this sounds familiar, it might be because I wrote a post like this about using App Connect Enterprise to work with topics from Event Streams. People seem to have found that post useful, so I thought I’d do something similar for topics in Event Endpoint Management this time.

To illustrate this, I’ll create a simple App Connect flow that consumes messages from a Kafka topic and publish them to an MQTT topic.

The key to getting this to work correctly first time is to make sure that values are accurately copied from Event Endpoint Management to App Connect.

To help with this, I use a grid like the one below.

The instructions in this post start with Event Endpoint Management, and explain how to populate the grid with the information you need.

Then the instructions will switch to App Connect, and explain how to use the values in the grid to set up your App Connect flow.

What this is Values you will see in my screenshots Your value
A Topic name
B Bootstrap address
C SASL mechanism
D SASL config required;
E Security protocol
F Certificate
G Certificate password
H Username
I Password
J Policy project name
K Policy name
L Security identity name
M Truststore identity name


Understanding windows in Event Processing

Wednesday, October 11th, 2023

Event Processing (one of the new capabilities of IBM Event Automation) makes it easy to perform stateful processing of streams of events from Kafka topics. In this post, I want to drill down a little into how windowed processing behaves.

I’ve enjoyed the chance to see the solutions that people have started to build with the tool. As part of this, I’ve been helping several people to understand the results produced by the event processing flows they’ve made.

These often started with different questions, such as:

  • Why hasn’t my flow produced any results?
  • Why isn’t my one-minute window producing one result every minute?
  • Why did the last one event on my Kafka topic cause results to be produced for several different windows?
  • etc.

However, these are often symptoms of a single common question: how windowed processing operations behave.

I’ve tried to come up with simple ways to demonstrate how it works, so in this post I want to share how I’m currently explaining it.

What can you do with IBM Event Automation?

Sunday, July 9th, 2023

This is IBM Event Automation : a new product we released last month to help our clients create event driven solutions.

I’ve written a 200-word summary of what IBM Event Automation is, but in this post I wanted to dive a little bit deeper and show what it can do.


What is IBM Event Automation?

Tuesday, July 4th, 2023

A summary of IBM Event Automation in under 200 words.

Last week was the first release of IBM Event Automation. I’ve been asked what it’s all about, so I thought it’d be helpful to have a brief summary to point people at.

IBM Event Automation is a collection of three components, designed to help companies be productive in creating event-driven solutions.


An introduction to Kafka Connect and Kafka Streams using Xbox

Sunday, June 18th, 2023

This is a talk I gave at Kafka Summit last month. It was an introduction to the Java APIs for Kafka Connect and Kafka Streams, using data from Xbox to bring the examples to life.

Confluent require personal details to watch recordings from Kafka Summit – sorry


Using Xbox to get started with Kafka Connect & Kafka Streams

Wednesday, May 17th, 2023

It’s easy for developers who aren’t immersed in all-things-Kafka to assume that “Apache Kafka” just means an event backbone: something that hosts topics (and perhaps the client libraries to produce and consume messages using those topics). But Kafka is more than that. It is an ecosystem of tools that enables a complete event-streaming application.

That was the premise of this talk, recorded at Devoxx UK, which I gave to a room of Java developers. I introduced them to two other bits of Kafka: Kafka Connect (for getting data in and out of Kafka topics from external systems) and Kafka Streams (for developing stream processing applications).

Because they were Java developers, I thought the best way to give them a flavour of these tools was to show them the APIs, and walk through an example solution made using the APIs.

The example solution used Kafka tools to process data from Xbox – mostly because I’m a gamer and it made for a fun, if silly, demo.

recording of the talk at