Roger Sessions

Website

• ObjectWatch (no longer maintained)
• RogerSessions.com
• Simple Architectures (no longer maintained)

Author

• From the website ..."Roger Sessions is the world's leading expert in IT Complexity Analytics. He has been interviewed by ComputerWorld, CIO, Information Age, and Information Week, among others, and is often quoted by Gartner and other industry pundits.For more than a decade, his books and white papers have defined the field of IT Complexity Analytics. He has been honored as a Fellow of the International Association of Software Architects for his many contributions to the field. His SIP methodology is the gold standard for Complexity Management, and is the only approach to simplification that has ever been granted a U.S. patent."

Publications

• Simple Architectures for Complex Enterprises (Amazon)
• White Papers
• Books

Partition to Reduce Complexity

• 
  

Training

• Available at RogerSessions.com

Mike's Notes

• A linear increase in functionality and dependency leads to a logarithmic increase in complexity.
• The rise in complexity and risk of failure in big IT projects is a power law.
• Partition and simplify to reduce complexity
• Partitioned chunks of functionality then suitable for Agile teams
• The maths is sound
• Puts maths behind what Martin Fowler writes
• Not in contradiction with Zachman's ontology
• Complements Google reWork study results
• Training is expensive

Repository

• I did an extensive search on the web of everything available by Roger Sessions.
• Stored at Work > Research Projects > Computer Architecture > Roger Sessions

Cliff Richardson - A Pattern Language for Microservices

Website

• www.microservices.io 
• Plain Old Objects
• Eventuate
• Chris Richardson Consulting

Author

"Chris Richardson is a developer and architect with over 20 years of experience. He is a Java Champion and the author of POJOs in Action, which describes how to build enterprise Java applications with POJOs and frameworks such as Spring and Hibernate. Chris is the founder of the original CloudFoundry.com. He now spends his time providing microservices consulting and training and working on his third startup, Eventuate, Inc. Chris has a computer science degree from the University of Cambridge in England and lives in Oakland, CA."

Summary

From the home page ..."Microservices - also known as the microservice architecture - is an architectural style that structures an application as a collection of services that are

• Highly maintainable and testable
• Loosely coupled
• Independently deployable
• Organized around business capabilities.

The microservice architecture enables the continuous delivery/deployment of large, complex applications. It also enables an organization to evolve its technology stack."

Contents

How to apply the patterns

Application architecture patterns

• Monolithic architecture
• Microservice architecture

Decomposition

• Decompose by business capability
• Decompose by subdomain

Deployment patterns

• Multiple service instances per host
• Service instance per host
• Service instance per VM
• Service instance per Container
• Serverless deployment
• Service deployment platform

Cross cutting concerns

• Microservice chassis
• Externalized configuration

Communication style

• Remote Procedure Invocation
• Messaging
• Domain-specific protocol

External API

• API gateway
• Backend for front-end

Transactional messaging

• Transactional outbox
• Transaction log tailing
• Polling publisher

Service discovery

• Client-side discovery
• Server-side discovery
• Service registry
• Self registration
• 3rd party registration

Reliability

• Circuit Breaker

Data management

• Database per Service
• Shared database
• Saga new
• API Composition new
• CQRS
• Event sourcing
• Application events

Security

• Access Token

Testing

• Service Component Test
• Consumer-driven contract test
• Consumer-side contract test

Observability

• Log aggregation
• Application metrics
• Audit logging
• Distributed tracing
• Exception tracking
• Health check API
• Log deployments and changes new

UI patterns

• Server-side page fragment composition
• Client-side UI composition

Presentations

• https://microservices.io/presentations/index.html

Mike's Notes

• Has a useful outline of options to choose from when considering using Microservices
• Good diagrams
• Has written a book
• Offers training
• Has skin in the game

Next on List is DevOps

So, having completed a crash course in DevOps over the last few months, the next task is actually setting up DevOps as part of the stack before I go any further.

So far, I haven't even needed to use formal version control with the refactoring. Over the last 18 months, it was pretty much "snip snip snip" into microservices with a bit of a tidy-up along the way. All looks good, and it works in a rough sort of way.

But it is a very different story now, getting it ready to deploy to the cloud so people can use it.

Criteria

What am I looking for when setting up DevOps?

• Version control
• It has to scale, be robust and reliable
• Automated builds
• Automated testing
• Automated deployment to multiple cloud environments
• Automated everything
• Continuous development
• Great for teams and remote developers
• Frequent small commits to the main branch and test
• It can also generate documentation
• Great reporting
• Great integration with other tools via open API
• Can include Database versioning
• Continuous Integration (CI)

Languages

It must work with Java, Python, Julia, SQL, CFML, AJAX, XML/XSD, JSON/YAML, Javascript, HTML5, CSS, and more.

Options

I prefer to go open-source, with a command line and good GUI available, and be well-documented.

So what is out there?