微服务架构依赖(Microservice Architecture dependency)

 我已经阅读了很多关于微服务架构的内容，但有一件事我不明白如何实现并希望你可以帮助我... 
 
 假设我有一个web-api-endpoint，它接收OrderMicroservice负责处理的命令。 当订单被放置时，必须更新库存，以便OrderMS向订户发布事件（使用例如Nats的pub / sub），而InventoryMS将更新库存，因为它订阅当前事件/消息....我想要松散耦合架构并使用asynch调用对给定信息感兴趣的模块/ MS。 
 
 如果您有1个InventoryMS实例，那么情况将完全正常但如果您横向扩展了InventoryMS会发生什么情况，即有5个InventoryMS实例并且他们都订阅inventory.change.event并将尝试更新库存？ 
 
 我应该使用什么样的架构或消息模式来实现这样的场景，因为我可以在MS彼此依赖时使用松耦合架构？ 一种方式是通过使用断路器模式的REST调用在内部进行通信，但后来我觉得我构建了具有一定智能性的断路器（断路器）...... 
 
 谢谢你的帮助！ 

I have read a lot about microservice architecture but there is one thing that I dont understand how to achieve and hope you can help me with this...
 
Lets say I have a web-api-endpoint that recieves orders that an OrderMicroservice is responsible to handle. When order is put Inventory must be updated so OrderMS publish an event to subscribers (pub/sub using for example Nats) and InventoryMS will update the inventory due to it is subscribing to current event/message....I want to have a loose coupled architecture and use asynch calls to modules/MSs thats are interested in given info. 
 
Given scenario will work perfectly fine if you have 1 instance of InventoryMS but what happens if you have scaled the InventoryMS horizontally i.e there are 5 instances of InventoryMS and all of them subscribes to inventory.change.event and will try to update the inventory?
 
What kind of architecture or message pattern should I use for a scenario like this with horizonatally scalled MS's so I can have a loose coupled architecture when MSs are dependent of each other? One way is that communication internally is made by REST-calls using circuit breaker pattern but then I feel that I build a monolite of MSs with some smartness (the circuit breaker)...
 
Thanks for your help!

原文：https://stackoverflow.com/questions/43378165