搞笑談軟工

Event Sourcing (18): Implementing Idempotent

July 9 14:20~16:20 ▲NotifyBoard implements Idempotent architecture diagram foreword Teddy introduced why Event Handler needs to have Idempotent in <Event Sourcing (16): Event Semantics and Idempotent in Distributed Systems>. This episode takes the Event Handler—NotifyBoard that generates GetBoardContent in the ezKanban system as an example (please refer to <Event Sourcing (10) ): Implement Projector >),

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Event Source (17): Read the events stored in the hand-carved Event Store

July 7 18::09~19:21; 21:15~23:23; July 8 13:45~16:27 ▲Store Checkpoints in the Event Store foreword Although using EventStoreDB, a database specially designed for Event Sourcing and CQRS, can reduce a lot of development work, in practice developers may only use relational databases due to company requirements or project constraints. In this case, you must simulate the

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Event Sourcing (16): Event Semantics and Idempotent for Decentralized Systems

July 6 23:14~24:00; July 7 00:00~01:39 ▲I’m almost exhausted XD foreword The reason why villagers use Event Sourcing and CQRS is to develop microservices in many cases. The microservice architecture is a distributed system. Compared with the centralized system, the distributed system has the characteristics of heterogeneity, easy expansion, robustness, high fault tolerance and low

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Event Sourcing (12): Snapshots to Accelerate Aggregate Reads

Original link: https://teddy-chen-tw.blogspot.com/2022/07/12.html July 04 21:23~23:39 ▲Figure 1: Using snapshots to accelerate Aggregate read speed foreword The Event Sourcing system is very simple and fast on the writing side, but reading because it needs to use all the domain events to which the Aggregate instance belongs to get the latest status one by one, it

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Event Sourcing (12): Snapshots to Accelerate Aggregate Reads

Original link: https://teddy-chen-tw.blogspot.com/2022/07/12.html July 04 21:23~23:39 ▲Figure 1: Using snapshots to accelerate Aggregate read speed foreword The Event Sourcing system is very simple and fast on the writing side, but reading because it needs to use all the domain events to which the Aggregate instance belongs to get the latest status one by one, it

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Event Sourcing (11): Writing JavaScript to Generate Custom Projections in EventStoreDB

Original link: https://teddy-chen-tw.blogspot.com/2022/07/11javascripteventstoredb.html July 04 18:38~19:46 ▲Figure 1: User-defined projection program of EventStoreDB foreword The previous episode introduced how ezKanbana implements Projector to generate the data required by the Read Model in the PostgreSQL database. This episode uses the customized Projection function of EventStoreDB to create another form of Read Model. *** Generate event projection

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Event Sourcing (11): Writing JavaScript to Generate Custom Projections in EventStoreDB

Original link: https://teddy-chen-tw.blogspot.com/2022/07/11javascripteventstoredb.html July 04 18:38~19:46 ▲Figure 1: User-defined projection program of EventStoreDB foreword The previous episode introduced how ezKanbana implements Projector to generate the data required by the Read Model in the PostgreSQL database. This episode uses the customized Projection function of EventStoreDB to create another form of Read Model. *** Generate event projection

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Event Sourcing (8): What is CQRS?

Original link: https://teddy-chen-tw.blogspot.com/2022/07/8cqrs.html July 02 06:35~08:20 ▲Figure 1: ezKanban applies CQRS architecture diagram foreword CQRS is the abbreviation of Command Query Responsibility Segregation , which is translated into ” command and query responsibility separation ” in Chinese. Today we introduce what CQRS is and what problems it can solve. *** origin CQRS is a design

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Event Sourcing (8): What is CQRS?

Original link: https://teddy-chen-tw.blogspot.com/2022/07/8cqrs.html July 02 06:35~08:20 ▲Figure 1: ezKanban applies CQRS architecture diagram foreword CQRS is the abbreviation of Command Query Responsibility Segregation , which is translated into ” command and query responsibility separation ” in Chinese. Today we introduce what CQRS is and what problems it can solve. *** origin CQRS is a design

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