Re: [soa-rm] microservice database consistency

[rexbroo <rexb@starbourne.com>]

The Single Database per Microservice pattern is a well established goal for Microservice design and aligns with the Single Responsibility Principle, though it is not as easily achieved as it seems when you consider that there may be multiple instances of a given Microservice, especially where those instances are spun up at need by load balancing in the cloud under PaaS implementations.

As the author says in an event-driven architecture a Microservice publishes an event when it’s data changes and other services consume that event and update their data. That is, of course, an oversimplification of a process where duplicate notifications must be prevented. Also, providing for eventual consistency in persistent datastores is something that has to be addressed. This is where our effort to figure out heuristics for scoping Microservices and their interactive grouping can provide value. The question is how to structure a set of interrelated Microservices such that they can work together optimally.

Lots to think about.

Rex

On 2/2/2017 12:37 PM, Ken Laskey wrote:

This has been a continuing topic of discussion and I found some info that actually covers this in the level of detail where you an envision a solution.

First see http://microservices.io/patterns/microservices.html, specially 

How to maintain data consistency?

and then the link http://microservices.io/patterns/data/event-driven-architecture.html.

Thoughts?  Continuing questions?

 

Ken

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Rex Brooks
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