Exploring Axon

In this episode I spoke with Simon Zambrovski of Holisticon about event handling and sagas in Axon Framework. We covered other topics such as query handling, storage, event processors, Axon Server, and more. 

Just a note that in this episode Simon referenced an episode about event streaming vs. event sourcing that I recorded with Allard, but I mistook that episode with another one I did with Steven on message handling. I do recommend you to listen to both of these episodes if you haven’t done so yet, as they are relevant to our topic.

Simon and I are active on Twitter @zambrovski and @SaraTorrey

For more information about us visit axoniq.io

In this episode I spoke with Evelyn van Kelle and Kenny Baas-Schwegler,  who work together as a socio-technical organizational designer and a software architect. 

Evelyn and Kenny work together in consulting tech companies in finding better ways when designing systems, while working smoothly in teams, and when needed, resolving conflicts. We discussed the definition of “The Vicious Cycle of Unsustainable Software Development”, we talked about the priorities when designing systems in DDD, RDD, and more. We also talked about how to recognize goals and values in teams, biases, the process of slow and fast thinking, managing priorities, and much more. This was a really great conversation and I hope you enjoy it, and let’s have a listen. 

Evelyn and Kenny teach various workshops to help teams identify the important decisions when designing software systems. They do this by helping teams find a safe space to communicate and make decisions together. They use techniques such as visual collaborative practices, Deep Democracy and Cynefin framework. 

We finished our conversation with the importance of conflict, and ways of resolving it. Kenny shared some great ways of facing conflicts and techniques of tackling this uncomfortable topic in every team with me.

You can learn more about Evelyn on her website and to learn more about Kenny visit his website. 

In this episode I spoke with Steven van Beelen, the lead Axon Framework developer, about event replays, and various types of event processors. 

We talked briefly about Subscribing Event Processors, and in much more detail about Tracking Event Processors, tokens, and replays. Steven also shared a sneak-peak review of a feature he is currently working on for the next major release of Axon Framework. We also talked about Event Sourcing and how to deal with conflict resolvers. 

You can find us on Twitter: @SaraTorrey, @smcvbeelen & @axon_iq

Our YouTube channel has many helpful videos: https://www.youtube.com/channel/UCQb0g7zJCWrzkpxznSUkERw

Axon Reference Guide: https://docs.axoniq.io/reference-guide/

For more information about AxonIQ visit axoniq.io

In this episode I spoke with Rebecca Wirfs-Brock,  a software engineer, architect and consultant. While attending the University of Oregon as a Computer Science student, Rebecca also double majored in Cognitive Psychology. For the past twenty plus years, she has been implementing her education and learnings in psychology in her consultancy and workshops for software designers and IT businesses. Her work focused on Object-Oriented Designs and Object-Oriented Programming, before coming up with Responsibility-Driven Design. Her ideas on this approach of development were the inspiration for many others that came up with other xDD methods, namely Eric Evans in his development of Domain-Driven Design. 

Rebecca has also done extensive research in Design Heuristics. The idea of heuristics was initially explored by Dr. Billy Vaughn Koen, a nuclear physicist and a professor emeritus at UT Austin. She then went further and examined these heuristics and their connections with patterns in the realm of software design and architecture. We explored these ideas in some detail during our talk. 

We then discussed a couple of her many workshops; in particular the importance of storytelling in designing software systems, and software architects and the process of making decisions when designing an application or system. 

Rebecca is the author of Designing Object-Oriented Software and Object Design: Roles, Responsibilities, and Collaborations. 

To learn more about Rebecca’s workshops, blogs, and more visit her website. You can read her article on heuristics and patterns here. Rebecca has given many fantastic talks on the topic of Design Heuristics in various conferences. You can find a few of them below: 

https://www.youtube.com/watch?v=2qcFEagDAuE

https://www.youtube.com/watch?v=fWCt5KWfTuo

https://www.youtube.com/watch?v=TP3xTZi_Qn8

You can find us both on Twitter @rebeccawb @SaraTorrey. And on LinkedIn: Rebecca & Sara.

For more information about AxonIQ visit axoniq.io

In this episode I spoke with Vijay Nair,  software architect and designer, as well as a Domain-Driven Design, CQRS, and ES evangelist. We talked about his experience of learning about DDD, CQRS, Event Sourcing, and later on Axon Framework and Axon Server. 

Vijay is continuously researching new tools and technologies in the realm of DDD, CQRS, and Event Sourcing. He is a writer for AxonIQ, InfoQ, and other platforms. He has written the book Practical Domain-Driven Design in Enterprise Java. He will soon publish his second book The pocket guide to build applications based on CQRS and Event Sourcing utilizing Axon co-written with Allard Buijze. He is also starting a newsletter this month at LinkedIn that covers his findings, recommendations, and more which we talked about during our conversation. We also talked about Akka and Kafka and whether or not we can use them with Axon. Lastly, we discussed some tools to help design and model systems and projects.

To learn more about Vijay and his books visit his website. 

You can find Vijay’s articles on our website and at InfoQ, 

You can also find Vijay and myself on LinkedIn. 

You can find us both on Twitter @SaraTorrey @FusionVJ

In this second episode Simon Zambrovski and Jan Galinski of Hilisticon continued sharing their experiences of working with Axon Framework and Axon Server. We talked further about distributed scenarios, deployment strategies, and operation modes. Amongst the great topics we touched, Simon detailed deployment strategies:

• Monolithic Core

Jan then explained the 6 components of the Operation Modes:

• Command Model

They also talked about some of the challenges that they have faced along the way and some of the solutions to these issues. 

Simon and Jan are active on Twitter @zambrovski and @jangalinski. You can find me @SaraTorrey

For more information about us visit axoniq.io

This is the first of the 2-episode podcast mini series I spoke with Simon Zambrovski and Jan Galinski of the Hamburg based IT consulting company, Holisticon. We discussed their experience of using Axon Framework and Axon Server. 

They shared how and why they became interested in Axon Framework and later Axon Server, which version of Axon they started with, and what made them fall in love with the framework. They also came up with some great ways of organizing the structure of their systems that they shared with me. One of which is the five messages that are distributed. Jan explained these messages as: 

• Command to reflect the intent of change (directed)

In the next episode they will elaborate more on the distribution cases. They also talked about a fun project that they are working on using Axon Framework, involving table soccer scoring and more. 

Simon and Jan are active on Twitter @zambrovski and @jangalinski. You can find me @SaraTorrey

For more information about us visit axoniq.io

In this episode I spoke with my colleague and Axon Framework's lead developer, Steven van Beelen about message versioning and how it can be achieved through Axon Framework. This process is done mainly for the events, but Steven also briefly discussed other types message versioning and object versioning. 

For more information, please visit our Reference Guide. 

For questions or comments, please join our community. 

Steven and Sara are active on Twitter. Make sure to follow them there for up to date information on AxonIQ. 

Join our trainings and events. 

Thank you for listening, and Happy Coding! 

In this episode my colleague Yvonne Ceelie and I talked about Set Based Validation and Sagas in Axon Framework. 

We discussed:

Set Based Validation

• What is a 'set' and what is the meaning of 'set based validation'?

Saga: 

• Similarities and differences between Sagas and Aggregates

Yvonne has a blog about Set Based Validation coming up soon that you can find here. You can also find the code samples for Set Based Validation here. 

Yvonne is active on LinkedIn and on discuss.axoniq.io.

To find out more about Axon trainings, please visit us here. For more information on AxonIQ, please visit our website.