[design] Event-driven system pattern

Watch note for The Many Meanings of Event-Driven Architecture • Martin Fowler

4 event driven patterns

Event notification

    啊就是類似 GUI  一個thread在while loop 聽event...

• Decouple receiver from sender

Event-carried state transfer

    啊就是將event存成state 傳遞...

• Decoupling
• Reduced load on supplier 

Event sourcing

    啊就是 log 咩 RAFT it is...

• Create event object and persist the object
• Process the persisted object
• No state, can restore the state machine from log    (like git(or other version application) system is using event sourcing)

can be used in:

• audit
• debugging
• historic state
• alternative state
• memory image        

Command Query Responsibility Segregation(CQRS)

    啊就是 rwlock啊...

• Seperate read/write into two application.
• Write: Command model
• Read: Query model

Reference:

https://martinfowler.com/