Notification Event Pattern
The notification event pattern uses a small event message to indicate that something has changed (e.g. New or Updated order). The event contains a reference to the data that has changed but very …
Event-driven architecture
Patterns for event-driven systems, from notification and stateful events through event sourcing and integration to measuring consistency. Written in 2017 and migrated from the Jekyll site, with the diagrams now rendered by puml.
Event-Carried State Transfer Pattern
One thing about developing software - it is never dull. I have been lucky to be on projects that are on the leading edge with technologies and patterns that become mainstream. Event driven …
Event Sourcing
Event Sourcing is a fascinating design pattern. In an Event Sourced applications/systems instead of storing the current state we derived the current state from a list of events. Many articles and …
Consistency
Consistency can be defined as an absence of a contradiction. For distributed event driven systems data state inconsistencies are a fact of life. First lets consider a direct call system. In this case …
Measuring Consistency
This is a followup to consistency. Specifically this is about measuring consistency in a distributed system within different consistency scopes. Event or message driven systems using CQRS present the …
Integrating Event Driven systems
'Event driven' is used to describe a wide range of application and system architectures so it is important to define some context. icon:tag[]: Event driven distributed systems that use asynchronous …
Compensating Actions
This is a followup to consistency. Specifically this is about measuring consistency in a distributed system within different consistency scopes. Event or message driven systems using CQRS present the …