Edition 0 Updated to asp. Net core 0

Drawbacks of the API Gateway pattern 
•
The most important drawback is that wh
en you implement an API Gateway, you’re coupling that 
tier with the internal microservices. Coupling like this might introduce serious difficulties for your 
application. Clemens Vaster, architect at the Azure Service Bus team, refers to this potential 
diff
iculty as “the new ESB” in the “
Messaging and Microservices
” session at GOTO 2016.
•
Using a microservices API Gateway creates an additional possible single point of failure. 
•
An API Gateway can introduce increased response time due to the additional network call. 
However, this extra call usually has less impact than having a client interface that’s too chatty 
directly calling the internal microservices. 
•
If not scaled out properly, the API Gateway can become a bottleneck. 
•
An API Gateway requires additional development cost and future maintenance if it includes 
custom logic and data aggregation. Developers must update the API Gateway in order to expose 
each micro
service’s endpoints. Moreover, implementation changes in the internal microservices 
might cause code changes at the API Gateway level. However, if the API Gateway is just applying 
security, logging, and versioning (as when using Azure API Management), this additional 
development cost might not apply. 

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48 
CHAPTER 3 | Architecting container and microservice-based applications 
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If the API Gateway is developed by a single team, there can be a development bottleneck. This 
aspect is another reason why a better approach is to have several fined-grained API Gateways 
that respond to different client needs. You could also segregate the API Gateway internally into 
multiple areas or layers that are owned by the different teams working on the internal 
microservices.