Exploring Axon

Collaborative Modeling 2.0 - with Evelyn van Kelle & Kenny Baas-Schwegler

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. 

Event Replay & Event Processing - with Steven van Beelen

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

RDD, Design Heuristics and More - with Rebecca Wirfs-Brock

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

 

Axon with Akka, Kafka and more - with Vijay Nair

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

Collaborative Modeling - with Kenny Baas-Schwegler

In this episode I spoke with Kenny Baas-Schwegler, a socio-technical organizational designer and software architect. 

 

I asked him about his experience with BDD, DDD, Continuous Delivery, Microservices and more, as well as how he came to know these concepts. 

He teaches various workshops to help teams identify the important decisions when designing software systems. He does this by defining the Bounded Contexts, the culture and language surrounding these contexts, and he uses 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.

 

To learn more about Kenny visit his website. 

You can find us both on Twitter @SaraTorrey @kenny_baas

For more information about AxonIQ visit axoniq.io

Using Axon - Part 2 - with Simon Zambrovski & Jan Galinski

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
• Distributed Core
• Additional Projection
• Orchestration

Jan then explained the 6 components of the Operation Modes:

• Command Model
• Command Client
• Orchestrator
• Query Model
• Query Client
• Event Subscriber

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

 

Using Axon - Part 1 - with Simon Zambrovski & Jan Galinski

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)
• Command response to reflect if it was successful or not (directed)
• Event to sync Command model with the Query model (broadcast)
• Query to reflect the request for data (unicast)
• QueryResponse to transport the query result data (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

Message Versioning (Upcasters) - with Steven van Beelen

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! 

Set Based Validation & Sagas in Axon Framework - with Yvonne Ceelie

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'?
• What about an example?
• Two Models in CQRS: Command and Query Models
• How can we ensure consistency?
• Aggregates and consistency rules in Aggregates
• How about Parameter Resolvers?

Saga: 

• Similarities and differences between Sagas and Aggregates
• Sagas in Axon vs. Saga database patterns - the new name for Sagas in Axon 
• Managing complex business processes
• Annotations for Saga
• Test fixtures for Sagas in Axon Framework
• Some things to keep in mind when using Sagas

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.
You can always connect with me on LinkedIn or Twitter.

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

Event Modeling - with Adam Dymitruk

In this episode I talked with Adam Dymitruk, the creator of Event Modeling. Listen until the end for a great surprise, Adam has for you all.

In this episode Adam and I discussed:

• the entire process of Event Modeling with some examples and details
• the ideas behind the concept of Event Modeling
• some of the differences between Event Storming and Event Modeling
• Event Modeling storyline and swimlanes
• The importance of UI/UX 
• Patterns - Scenes of a Movie
• Components of Event Modeling
• Input/Output
• States
• Limitations
• Given-When-Then
• State Change and State View
• Translation Patterns
• Automation
• Cost and Agile Programming
• Blueprint

We then talked about some of the activities that are keeping him busy, within the next few months: A 40-Hour Virtual Workshop, His Book and Teaching Event Modeling at the University of Victoria

Also here is a list of some great resources: 

• Adam's Website
• His Blog "Event Modeling: What is it?"
• Event Modeling Slack Channel and Intro Videos
• Adam's presentation at AxonIQ's virtual Conference 
• The Event-Driven Meetup
• Sara's Blog Series "From Model to Code"

Adam and I are both very active on Twitter: @adymitruk @SaraTorrey

For more information about AxonIQ, please visit us at axoniq.io or visit our Events page

Clustering in Axon Server - with Milan Savic

In this episode, I spoke with my colleague, Milan Savic about clustering in Axon Server. We discussed how different nodes are used in Axon Server Enterprise Edition, and Milan also explained what RAFT protocol is and why we use it in Axon Server. 

Milan also has a wonderful talk about this topic, where he gets into more detailed explanation of clustering in Axon Server, as well as RAFT protocol. You can read further about RAFT protocol here. 

Our colleague Bert Laverman also has a great article on installing and running Axon Server, which explains different kinds of nodes and their responsibilities in Axon Server.  

You can follow Milan, Bert, and I on Twitter: @MilanSavic14 @BertLaverman @SaraTorrey

For more information on our webinars, trainings, and blogs visit us on axoniq.io

Why Axon Server? - with Milan Savic

In this episode, I spoke with my colleague, Milan Savic about Axon Server. We discussed why to use Axon Server and the difference between Axon Server Standard Edition and Axon Server Enterprise Edition. For more information on Axon server, please visit our website.

For instructions on how to install and run Axon Server, please see to this article by my colleague Bert Laverman.

 

You can follow Milan, Bert, and I on Twitter: @MilanSavic14 @BertLaverman @SaraTorrey

For more information on our webinars, trainings visit us on axoniq.io