I have setup multiple instances of my microservice and registered to my eureka server. It uses ribbon for client side load balancing and uses zuul as gateway server. All usual stuff. I would like to capture the logs of which instance of my service is responding for each request. So that I can able to bring some conclusion based on my usage of each instances. How to do that?
You can try to set the loglevel just of the LoadBalancerContext to debug in application.properties
#logging
logging.level.com.netflix.loadbalancer.LoadBalancerContext=DEBUG
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I have a eureka server running on test server and multiple services registers from test server to this eureka server.
Now problem is sometimes developers also connect their local microservice instance for some service to eureka. Due to this it shows multiple instances for that service on eureka and load balancer starts sending request to local servers as well from feign client. That causes issues in testing as test server is not able to connect local developers machine in feign client calls.
I instructed developers to set eureka.client.register-with-eureka=false from local but still if someone connects how can I stop that. Is there a way that eureka server registers only from specific IP (test server ip)? Or any other solution to prevent this problem?
For the services that you don;t want them to register, remove #EnableDiscoveryClient from the services. #EnableDiscoveryClien lives in spring-cloud-commons and picks the implementation on the classpath. This will stop your services from getting discovered but then you won;t be able to make the Feign calls to other services and take the benefit of load balancing your calls.
I recently have learnt and practicing Microservice using Spring technology. I am currently writing a small program that has Eureka Server, Configuration Server, Gateway and Account service. I have all of my services register its instance to Eureka and have my Gateway gets its configuration from Configuration Server. After that, I got some question, should I my Account Service fetch its configuration directly from Configuration Server, or from Gateway because it can be done in both way. I think, if I decide to fetch it through Gateway, it might be better because Gateway is a load balancer, so in case if there are multiple Configuration Servers out there, I don't need to worry if any of them failed or down as Gateway can handle this for me. But, doing so, isn't I put too much weight on Gateway because it need to handle this and another requests. Furthermore, I am not sure and I can't find any information about if there is a way to load balancing Gateway or is it makes sense to do so?
Please advice and explain. Thank you.
Only user's requests from UI need to be passed via Gateway. Services should be able to fetch their configuration during startup disregarding whether gateway is online or doesn't exist at all.
Also I'd advise you to avoid registering config service in Discovery (Eureka). I suppose there is no need for your users to send requests to config service.
Along with spring cloud config and gateway documentation I'd recommend you to get familiar with these 2 books:
https://www.manning.com/books/enterprise-java-microservices
https://www.manning.com/books/spring-microservices-in-action
I am trying to set up a zuul proxy server which will act as a gateway service for other apis in my microservice architecture.
So far all the tutorials that I have come across have the discovery client and zuul proxy set up in different gradle modules while I am trying to set them up in the same gradle module.
I have defined the routes and can see that my services have been successfully registered in the eureka dashboard.
I have also verified that I can ping the services using a discovery client from my gatekeeper service but whenever I try to access the services from the URL, I get
"Load balancer does not have available server for client:xyz"
exception.
Can somebody please help me setting this up?
I have two machines (with same application) register to eureka server.
all requests to these services are through zuul proxy.
my application.properties of my backend services is:
spring.application.name=core
my application.properties of my zuul proxy is:
zuul.sensitiveHeaders=Set-Cookie
zuul.routes.address.path=/to-address/**
zuul.routes.address.url=http://localhost:8888
zuul.routes.service.path=/by-service/**
zuul.routes.service.url=CORE
I have two questions:
All three request below are working, which one should I use?
What is the difference with upper case and lower case?
http://localhost:9090/api/by-service/customer/1
http://localhost:9090/api/core/customer/1
http://localhost:9090/api/CORE/customer/1
When I call the service in the following way:
http://localhost:9090/api/to-address/customer/1
I noticed that a new session is being created by my core server, which force my user to login again. Any idea why?
As you can see it's the same method (same filter, same application...) with just a routing difference.
you need to use req.getRequestedSessionId() instead of req.getSession().getId().
I am new to spring cloud and going through some examples and material available online to make myself comfortable. However, while reading about ZUUL, some sites configured the routes in ZUUL's application.yml and some other sites mentioned that the requests will be forwarded to the respective microservice and no need to explicitly configure the routes. I was bit confused. For ex, in the below scenario what is the approach, to configure routes or to let zuul route automatically?
Let's say i have few micro services running and all of them along with ZUUL are registered to Eureka.
I have a front end which is running on a different port on the same server and needs to interact with the above micro services.
I also have few other applications (Running entirely on different servers) which need to interact with the above micro services for fetching the data.
TIA..
Did you use Zuul (which know microservices address through Eureka) to forward request between your micro-services ? if it's the case, you are using Server-Side Load Balancing pattern.
If you use a discovery service (Eureka in your case), i think the best approach it's to use Client-Side load balancing pattern for all inter-services requests (inside your system). (you can use Ribbon or RestTemplate for that).
You can use Zuul as a unified front door to your system, which allows a browser, mobile app or other user interface to consume services from multiple hosts without managing cross-origin resource sharing (CORS) and authentication for each one.
For example : a client (mobile app) request for all picture comments. The client dont need to know the Comments-service address. Only proxy address needed and Zuul will forward the request to the right service. You can do this in application.yml/.properties by
zuul.routes.comments.path=/comments/**
zuul.routes.comments.service-id=comments
The request will be GET www.myproxy.mycompany.com/comments. Dont forget the service name in your application.yml/.properties is very important (spring.application.name). It's the service-id in Zuul routes (which the same identifier in Eureka).
For some reason, your system need to request external services (as you mentionned in the 3th note). In this case, your external services are not a discovery client, Zuul can't look for the service-id from Eureka. you use routes as
zuul.routes.currencyprovider.path=/currencies/**
zuul.routes.currencyprovider.url=https://currencies.net/
with this route, all /currencies/** requests from your services THROUGH Zuul will be done.
with this approach you have one door for all your system. This is API Gateway pattern.
Sometimes your system need to aggregate multiple results from different services to response to client request. You can do this in Proxy (Zuul in your case).