So we have a Spring app which runs on localhost:8080
As part of a requirement we need this application to connect to a micro service. The micro service has 2 components.
One running on localhost:8888 - X
Another on localhost:7777 - Y
We have the spring discovery server running on localhost:8761
How can we connect to the micro service X or Y from the monolithic spring application through the discovery server.
We can directly connect to localhost:8888 or localhost:7777
But is there a way to do it through the discover server
There are 3 ways to do the call from the monolithic app to a microservice registered in the discovery-service:
After adding and enabling discovery service dependencies you can
inject eurekaClient bean and get an application url
("round-robinned" or not).
Use the #LoadBalanced restTemplate and send requests to
"http://service-name/url" where ribbon will change "service-name" to
a valid URL automatically
And finally the best option is to rely on feign client. It uses
discovery service implicitly.
Related
We took a micro service solution base on spring cloud and spring boot.Now we have a Netty project as a IoT protocol service, how can this netty service keep running (beacuse it need to maintain the connect) and discover all api of a new service which registered to eureka.
I am trying to setup a Spring Boot Admin server on a Cloud foundry. I am using the client Spring Cloud Discovery with SimpleDiscoveryClient configuration. We are not having any Thrid Party service discovery client like eureka. I can see the service getting registered to the spring boot admin server. But when i scale up any service, i see only one instance of that service and the actual number of instances are not reflected. I would like to know if that is possible without Eureka or any other service discovery, if yes how to achieve that without them.
Thanks
I am trying to create spring cloud microservices and also need to include eureka server and zuul as spring cloud tools. Now I created one module in my one spring boot project. I registered that service with eureka server. And also I created one spring boot project for adding zuul service discovery and also registered with eureka project.
Here my doubt is that When I am adding another module as another spring boot project, Can I register that application also with my current eureka server as client? What type of relation that eureka server project and microservice having? one-To-One or One-To-Many? Can I register 3 or 4 microservices with one eureka server as client?
Eureka Server will let you add as many microservices (modules of spring boot projects like you said).
From Spring Cloud landing page:
As long as Spring Cloud Netflix and Eureka Core are on the classpath
any Spring Boot application with #EnableEurekaClient will try to
contact a Eureka server on http://localhost:8761 (the default value of
eureka.client.serviceUrl.defaultZone):
That means that you can use a single eureka server for multiple microservices which are registered as clients to the eureka server.
So yes, it's a One-To-Many relationship.
You will want at one point to look into multiple Eureka servers used in load balancing, for redundancy purposes, but for now you will be fine.
With regards to the Netflix Eureka Service Registry, I have setup the Eureka Netflix Server using Tomcat 8.0.35 successfully. I have also got the basic Example Service & Client to communicate with each other. I'm still new to Eureka and the management decision is to use Eureka with Spring as several new applications are written around the Spring framework.
I have been following the wiki in order to understand how the communication works (But with little to no success with registering services).. Eureka Github Wiki.
My question is: Do I need to create my own Eureka Service & Client in order to maintain a registry of about 50 cloud instances? (If so, can you please point me in the right direction).
I have hands on experience with Consul/RESTfull API, and have implemented Consul in production (using php, and qbit); however the Netflix Eureka Registry look's as though I need to learn eureka/spring + client/server java programming? I'm still getting used to the following terms.
Eureka Server (I successfully got this working using Tomcat8/JDK1.8 + the eureka.war)
Eureka Service (Some kind of stand-alone RESTfull service that queries the Eureka-Server and listens for client requests)
Eureka Client (Java snippet to be embedded into the Java servlets/jsp)?
Zuul (A type of routing/load-balancing app - similar to HaProxy ?)
Ribbon (A type of routing/load-balancing app - similar to HaProxy ?)
I would like to get the Service & Client configured for mostly non-AWS cloud instances. The Eureka Wiki is not very helpful when it comes to creating a working eureka service & client. Any help to point me in the right direction to implement a Eureka based RESTfull system would be helpful.
I suggest you to read this documentation about spring-cloud : http://cloud.spring.io/spring-cloud-static/spring-cloud.html
It should be a good start to setup a few simple spring-boot/spring-cloud services and start to use advanced tools like zuul/ribbon/hystrix ...
There is a simple example of distributed system using Spring Boot and Spring Cloud Netflix.
This project contains the following microservices:
requestor and responder which communicates via REST/HTTP
gateway microservice - Spring Boot app + Zuul
discovery microservice - Spring Boot app + Eureka
Moreover, requestor microservice uses Hystrix library.
As you can see, Spring Cloud provides a really good wrapper for Netflix solutions. As a result, you can start quickly with minimal configuration.
I'm attempting to establish a discovery server with spring cloud Eureka which needs to connect to a secured client. I understand how to secure the Eureka sever itself - that isn't the issue. The issue is in the other direction - how to get Eureka to successfully communicate with a client service that itself is secured.
In other words; I have a discovery client that registers itself with Eureka. That client implements http basic authentication. It can and does successfully register itself with the discovery service, however when I attempt to utilize that service with a lookup to the discovery service, I get authentication failures (on the client service itself) which of course makes sense because I haven't specified any credentials anywhere and have no idea how to do so. Any assistance would be greatly appreciated.
Guessing from your tags you are using spring-cloud.
When you use your service (with RestTemplate or Feign or manually looking up and interacting with it), your request has nothing to do with Eureka. Eureka only provides you information about your services whereabouts. Once you (or some undelying logic) obtained the address of the service, you are directly communicating with it.