The setup:
I have a set of Spring Boot based microservices that are fronted by Spring Cloud Gateway, meaning every request that comes from UI or external API client first comes to Spring Cloud Gateway and is then forwarded to appropriate microservice.
The routes are configured in Consul, and Spring Cloud Gateway communicates with Consul to get the routes accordingly.
Requirement:
There is a need of some microservices communicating with each other with REST APIs. I would prefer this communication to happen via the Spring Cloud Gateway as well. This will help in reducing multiple services going to Consul for getting other service's details.
This means every service should know Gateway's detail at least. And there can be multiple instances of Gateways as well. How is this dealt with in bigger architectures?
Any example that I look up contains one service using Consul, or Gateway using the consul with one microservice. Couldn't understand how to extrapolate that design to a bigger system.
Related
TLDR : Is it okay to use controller class in spring gateway instead of routing in config class? I want to take data from one service and then pass it the response from that service to another.
I used spring cloud gateway to create an api gateway. I have several services that need to communicate. I currently only use the gateway for routing to the first service and then the first service is going to talk to other service by itself. But this is becoming troublesome now that I have a lot of services.
I am writing a microservice app by spring boot and spring cloud. I have five modules which are
API-Gateway (base on spring cloud gateway spect)
Discovery-Server (base on spring cloud Netflix Eureka service discovery)
Microservice-A (It is a spring boot app that includes our business)
Microservice-B (It is a spring boot app that includes our business)
Microservice-C (It is a spring boot app that includes our business)
All requests which come from users route to API gateway and through API gateway send to app A or B or C (these are not exposed out). Now I have a question, base on one business role, app A will need to call one rest endpoint of app B. Which approach is the best? I call app B endpoint from app A directly or I call by API-Gateway?
The API Gateway should serve as an ingress layer, it only accepts traffic which is coming from outside of your application (clients / external integrations). More details here.
Any internal communication between your microservices, should be a point-to-point interaction, that can be done in multiple ways. This answer describes that in more details.
So the API Gateway should not be concerned with orchestration of the microservices.
If I were you I'll use a message broker for microservices communication. Let the api gateway for external clients. I think we overuse the http protocol. With a microservice architecture we should try to think differently.
I have a few synchronous microservices working on production using Spring Boot 2.X version. Soon, we need to implement a gateway if the number of instances of each microservice is going to be increased. I read that Zuul was in a maintenance phase and was replaced by Spring Cloud Gateway which is by default asynchronous technology. My question is, can I still implement Spring Cloud Gateway with my microservices?
Yes, you can use Spring Cloud Gateway without any doubts.
Basically, asynchronous technology means that your resources/threads on Api Gateway won't be blocked waiting for the response from downstream services and that increases a throughput.
Now, once your blocking services complete their internal logic they respond back to Api Gateway using an originally opened connection. Api Gateway in turn responds back to your client.
I'm pretty much new to spring cloud gateway. I have configured routing with two different apps with 'path'. Now, I need some help/docs on
1. How to route to different instance of an app from spring cloud gateway?
2. How to enable sticky session?
My apps are not using spring boot/eureka. I do see that I can use lb://service-name if i'm using any discovery client (unfortunately that is not my case).
Thanks in advance.
IMHO:
How to route to different instance of an app from spring cloud gateway?
Routing to different instances is the basic job of what spring cloud gateway is doing. Spring cloud gateway implements the pattern named client side routing along with the ease of service discovery. So if you are not using any discovery server or your apps are not registered with any discovery server, you loose the dynamic discovery and routing feature, BUT still you can specify your server list (refer to Netflix Ribbon). Until then you can think about your routing strategy.
How to enable sticky session?
I suppose that's one requirement of your routing strategy - implement sticky session because you are not using shared session store. According to my limited knowledge of spring cloud gateway, sticky seems not being supported out of box. But it could be customized with a Filter, see shipped LoadBalancerClientFilter for reference.
Good luck!
i have created two java spring-boot micro services they are
1) producer
2) consumer
and i have used spring eureka server for service registration and discovery . it worked fine . then what is the use of Netflix Zuul.
Let's suppose you have 20 services to which user can interact to, and of course we are not going to expose each and every services publicly because that will be madness (because all services will have different ports and context), so the best approach will be to use an API gateway which will act as single entry point access to our application (developed in micro service pattern) and that is where Zuul comes into picture. Zuul act as a reverse proxy to all your micro-services running behind it and is capable of following
Authentication
Dynamic Routing
Service Migration
Load Shedding
Security
Static Response handling
Active/Active traffic management
You can go through documentation here
If you have enough experience in the domain, you could look at zuul as an API gateway like Apigee. It is very feature rich and touches up on a lot of different concerns like routing, monitoring and most importantly, security. And eureka as a service discovery platform that allows you to load balance (in Linux terms the nginx or haproxy) and fail over between your service instances.
Typically the backend services that perform the server side business operations (i.e. core) are not exposed publicly due to many reasons. They are shielded by some Gateway layer that also serves as reverse-proxy. Netflix Zuul serves as this gateway layer which easily gives you the capabilities as mentioned by #Apollo and here