I want to try out microservices using 2.5.4 spring boot and getting problems in discovery
Steps:
Created a RestTemplate with #LoadBalanced, and trying to call the service using "application name in the url"
I have the register and fetch registry true in properties (thought this should get available services?)
Error: No such host is known
I am trying
#Autowired
private DiscoveryClient discoveryClient;
and do
discoveryClient.getInstances("myappservice-name").forEach((ServiceInstance s) -> {
System.out.println(ToStringBuilder.reflectionToString(s));
});
But all examples tell to use an endpoint? or commandLineRunner. Both I'm looking for auto loading
https://spring.io/guides/gs/service-registration-and-discovery/
https://spring.io/blog/2015/01/20/microservice-registration-and-discovery-with-spring-cloud-and-netflix-s-eureka
Not ok to call the below for each app
#RequestMapping("/service-instances/{applicationName}") public
List<ServiceInstance> serviceInstancesByApplicationName(
How can I register automatically?
EDIT: More detailed question
(1) SERVICE App
bootstrap - spring.application.name=pluralsight-toll-service
application props
server.port=0
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
eureka.instance.instance-id=${spring.application.name}:${random.int}
eureka.instance.hostname=localhost
management.endpoints.web.exposure.include=*
App
#SpringBootApplication
#EnableEurekaClient
public class PluralsightEurekaTollrateServiceApplication {
I see app registered in eureka server
(2) Client
bootstrap
spring.application.name=pluralsight-tollrate-billboard
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
application.props
server.port=8081
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
management.endpoints.web.exposure.include=*
App
#SpringBootApplication
#EnableEurekaClient
#EnableDiscoveryClient
public class PluralsightEurekaTollrateBillboardApplication {
Controller
#LoadBalanced
#Bean
public RestTemplate restTemplate(RestTemplateBuilder builder) {
return builder.build();
}
#Autowired
RestTemplate restTemplate;
#RequestMapping("/dashboard")
public String GetTollRate(#RequestParam int stationId, Model m) {
TollRate tr = restTemplate.getForObject("http://pluralsight-toll-service/tollrate/" + stationId, TollRate.class);
Error: pluralsight-toll-service host is unknown
How can call service from client using the name
Fixed the issue
Its all down to client project dependencies
<!-- <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-netflix-eureka-client</artifactId>
<version>3.0.3</version>
</dependency> -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
The names are too close
spring-cloud-netflix-eureka-client is wrong
spring-cloud-starter-netflix-eureka-client is the right one
Because of the wrong one, I had to add eureka-client of com.netflix.eureka. Cleaned all and it works
(Also I was missing spring-cloud , as I was creating from eclipse. In future will use initializ only )
I want to use Eureka client with spring-cloud-starter-loadbalancer. But when I added configuration I get error. When I remove #LoadBalancerClient(name = "mail-service", configuration = LoadBalancerConfiguration.class) and LoadBalancerConfiguration class configuration it's working fine. I tried this code:
#FeignClient(name = "mail-service")
#LoadBalancerClient(name = "mail-service", configuration = LoadBalancerConfiguration.class)
public interface EmailClient {
#RequestMapping(method = RequestMethod.POST, value = "/engine/emails/register")
void setUserRegistration(CreateUserDTO createUserDTO);
}
#Configuration
public class LoadBalancerConfiguration {
#Bean
public ServiceInstanceListSupplier discoveryClientServiceInstanceListSupplier(ConfigurableApplicationContext context) {
return ServiceInstanceListSupplier.builder()
.withBlockingDiscoveryClient()
.withSameInstancePreference()
.withHealthChecks()
.build(context);
}
}
application.yml:
feign:
client:
config:
default:
connectTimeout: 5000
readTimeout: 5000
loggerLevel: basic
eureka:
client:
serviceUrl:
defaultZone: ${EUREKA_URI:http://localhost:8761/eureka}
fetchRegistry: true
healthcheck:
enabled: true
instance:
preferIpAddress: true
leaseRenewalIntervalInSeconds: 10
POM.xml dependencies
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>com.netflix.eureka</groupId>
<artifactId>eureka-core</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-loadbalancer</artifactId>
</dependency>
I get this error when I have only one target service.
[503] during [POST] to [http://mail-service/engine/emails/register] [EmailClient#setUserRegistration(CreateUserDTO)]: [Load balancer does not contain an instance for the service mail-service]
I use Release Train Version: 2020.0.3
Do you know what could be the problem?
Any application using load balancer should follow the below order
Start the Eureka Server
Start the instances of the Service one by one which have dependency
Any application relies on information from a service registry (i.e. Eureka). Until the application is registered with it's instances by the serviceId , the Eureka server will not be able to pick that instance while load-balancing.
In the code you have shared, the bean ServiceInstanceListSupplier is created in the configuration class along with the health checks ( .withHealthChecks() ). This is causing the application to fail as service has not been registered yet.
Also, the LoadBalancer config should not be in a #Configuration-annotated class instead, it should be a class passed for config via #LoadBalancerClient or #LoadBalancerClients annotation, as described here.
The only bean you need to instantiate is the ServiceInstanceListSupplier (if you add spring-cloud-starter-loadbalancer, LoadBalancerClientFactory etc. will be instantiated by the starter itself).
So your LoadBalancer configuration class should look like code below.
It should not be in the #Configuration class:
public class LoadBalancerConfiguration {
#Bean
public ServiceInstanceListSupplier instanceSupplier(ConfigurableApplicationContext context) {
return ServiceInstanceListSupplier.builder()
.withDiscoveryClient()
.withHealthChecks()
.build(context);
}
}
As explained in this link, the actual #Configuration class , will have the following annotation: #LoadBalancerClients(defaultConfiguration = LoadBalancerConfiguration .class).
Then, if you enable health-checks in the instances, it should work without any issues.
I've been working on a Spring/Spring MVC application and I'm looking to add performance metrics. I've come across Spring Boot Actuator and it looks like a great solution. However my application is not a Spring Boot application. My application is running in a traditional container Tomcat 8.
I added the following dependencies
// Spring Actuator
compile "org.springframework.boot:spring-boot-starter-actuator:1.2.3.RELEASE"
I created the following config class.
#EnableConfigurationProperties
#Configuration
#EnableAutoConfiguration
#Profile(value = {"dev", "test"})
#Import(EndpointAutoConfiguration.class)
public class SpringActuatorConfig {
}
I even went as far as adding #EnableConfigurationProperties on every configuration class as suggested on another post on StackOverflow. However that didn't do anything. The endpoints are still not being created and return 404s.
First let's clarify that you cannot use Spring Boot Actuator without using Spring Boot.
I was wrong about not being able to it without Spring Boot. See #stefaan-neyts
answer for an example of how to do it.
I created a sample project to show how you could convert a basic SpringMVC application using a minimal amount of Spring Boot auto-configuration.
Original source: http://www.mkyong.com/spring-mvc/gradle-spring-mvc-web-project-example
Converted source: https://github.com/Pytry/minimal-boot-actuator
I could have completely removed the dispatcher-servlet.xml and the web.xml files, but I kept them to show how to perform as minimal a change as possible and to simplify converting more complex projects.
Here is a list of steps I took to convert.
Conversion Process
Add a Java Configuration file annotated with #SpringBootApplication
Add the Application configuration file as a bean to the traditional xml configuration ( added it just after the context scan).
Move view resolvers into Application java configuration.
Alternatively, add the prefix and suffix to application.properties.
You can then inject them with #Value in your application, or delete it entirely and just use the provided spring boot view resolver.
I went with the former.
Removed Default context listener from the spring context xml.
This is important!
Since spring boot will provide one you will get an "Error listener Start" exception if you do not.
Add the spring boot plugin to your build script dependencies (I was using gradle)
Add a mainClassName property to the build file, and set to an empty String (indicates not to create an executable).
Modify dependencies for spring boot actuator
You can use actuator without spring boot.
Add this to pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-actuator</artifactId>
<version>1.3.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.3.5.RELEASE</version>
</dependency>
And then in your config class
#Configuration
#EnableWebMvc
#Import({
EndpointAutoConfiguration.class , PublicMetricsAutoConfiguration.class , HealthIndicatorAutoConfiguration.class
})
public class MyActuatorConfig {
#Bean
#Autowired
public EndpointHandlerMapping endpointHandlerMapping(Collection<? extends MvcEndpoint> endpoints) {
return new EndpointHandlerMapping(endpoints);
}
#Bean
#Autowired
public EndpointMvcAdapter metricsEndPoint(MetricsEndpoint delegate) {
return new EndpointMvcAdapter(delegate);
}
}
And then you can see the metrics in your application
http://localhost:8085/metrics
Allthough it is not a good idea to use Spring Boot features without Spring Boot, it is possible!
For example, this Java configuration makes Spring Boot Actuator Metrics available without using Spring Boot:
import java.util.Collection;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.actuate.autoconfigure.EndpointAutoConfiguration;
import org.springframework.boot.actuate.autoconfigure.PublicMetricsAutoConfiguration;
import org.springframework.boot.actuate.endpoint.MetricsEndpoint;
import org.springframework.boot.actuate.endpoint.mvc.EndpointHandlerMapping;
import org.springframework.boot.actuate.endpoint.mvc.EndpointMvcAdapter;
import org.springframework.boot.actuate.endpoint.mvc.MvcEndpoint;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
#Configuration
#Import({ EndpointAutoConfiguration.class, PublicMetricsAutoConfiguration.class })
public class SpringBootActuatorConfig {
#Bean
#Autowired
public EndpointHandlerMapping endpointHandlerMapping(Collection<? extends MvcEndpoint> endpoints) {
return new EndpointHandlerMapping(endpoints);
}
#Bean
#Autowired
public EndpointMvcAdapter metricsEndPoint(MetricsEndpoint delegate) {
return new EndpointMvcAdapter(delegate);
}
}
The Maven dependency:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-actuator</artifactId>
<version>1.3.5.RELEASE</version>
</dependency>
Though the answer is already accepted, I thought of updating my experience. I did not want to convert my application to spring boot using #SpringBootApplication. Refer to another question where I have mentioned the bare minimum code required.
As we already have Spring Boot Actuator 2.x, a recipe to include actuator to an existing Spring MVC project can look like this:
#Configuration
#Import({
EndpointAutoConfiguration.class,
HealthIndicatorAutoConfiguration.class,
InfoEndpointAutoConfiguration.class,
HealthEndpointAutoConfiguration.class,
WebEndpointAutoConfiguration.class,
ServletManagementContextAutoConfiguration.class,
ManagementContextAutoConfiguration.class,
})
#EnableConfigurationProperties(CorsEndpointProperties.class)
class ActuatorConfiguration {
#Bean //taken from WebMvcEndpointManagementContextConfiguration.class
public WebMvcEndpointHandlerMapping webEndpointServletHandlerMapping(WebEndpointsSupplier webEndpointsSupplier,
ServletEndpointsSupplier servletEndpointsSupplier, ControllerEndpointsSupplier controllerEndpointsSupplier,
EndpointMediaTypes endpointMediaTypes, CorsEndpointProperties corsProperties,
WebEndpointProperties webEndpointProperties) {
List<ExposableEndpoint<?>> allEndpoints = new ArrayList<>();
Collection<ExposableWebEndpoint> webEndpoints = webEndpointsSupplier.getEndpoints();
allEndpoints.addAll(webEndpoints);
allEndpoints.addAll(servletEndpointsSupplier.getEndpoints());
allEndpoints.addAll(controllerEndpointsSupplier.getEndpoints());
EndpointMapping endpointMapping = new EndpointMapping(webEndpointProperties.getBasePath());
return new WebMvcEndpointHandlerMapping(endpointMapping, webEndpoints, endpointMediaTypes,
corsProperties.toCorsConfiguration(),
new EndpointLinksResolver(allEndpoints, webEndpointProperties.getBasePath()));
}
#Bean
DispatcherServletPath dispatcherServletPath() {
return () -> "/";
}
}
I did include
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-actuator-autoconfigure</artifactId>
<version>2.1.18.RELEASE</version>
</dependency>
for compatibility with the baseline Spring version I've been using (5.1.19.RELEASE)
If your objective is to create an endpoint with metrics for Prometheus a.k.a. OpenMetrics, you can use the Prometheus JVM client which is compatible with Spring framework.
Add dependency:
<dependency>
<groupId>io.prometheus</groupId>
<artifactId>simpleclient_servlet</artifactId>
<version>0.16.0</version>
</dependency>
To collect metrics of requests, add as first filter in web-app/WEB-INF/web.xml:
<filter>
<filter-name>prometheusFilter</filter-name>
<filter-class>io.prometheus.client.filter.MetricsFilter</filter-class>
<init-param>
<param-name>metric-name</param-name>
<param-value>webapp_metrics_filter</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>prometheusFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
To expose metrics as HTTP endpoint, add servlet:
<servlet>
<servlet-name>prometheus</servlet-name>
<servlet-class>io.prometheus.client.exporter.MetricsServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>prometheus</servlet-name>
<url-pattern>/metrics</url-pattern>
</servlet-mapping>
After that you can see the metrics on the /metrics endpoint.
Time passes, we have Spring 6, SpringBoot 3, JakartaEE as a baseline, but people are still looking to add actuator to legacy spring applications. So a small update: spring + actuator without spring-boot. In fact not much changes (and the changes have already been pointed out).
The dependencies
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>6.0.3</version>
</dependency>
<dependency>
<groupId>jakarta.servlet</groupId>
<artifactId>jakarta.servlet-api</artifactId>
<version>6.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-actuator-autoconfigure</artifactId>
<version>3.0.1</version>
</dependency>
The actuator configuration
#Configuration
#ImportAutoConfiguration({
EndpointAutoConfiguration.class,
WebEndpointAutoConfiguration.class,
ServletManagementContextAutoConfiguration.class,
ManagementContextAutoConfiguration.class,
HealthContributorAutoConfiguration.class,
InfoEndpointAutoConfiguration.class,
HealthEndpointAutoConfiguration.class,
HeapDumpWebEndpointAutoConfiguration.class,
ThreadDumpEndpointAutoConfiguration.class,
LoggersEndpointAutoConfiguration.class,
PrometheusMetricsExportAutoConfiguration.class,
})
#EnableConfigurationProperties(CorsEndpointProperties.class)
class ActuatorConfiguration {
#Bean //taken from WebMvcEndpointManagementContextConfiguration.class
public WebMvcEndpointHandlerMapping webEndpointServletHandlerMapping(WebEndpointsSupplier webEndpointsSupplier,
ServletEndpointsSupplier servletEndpointsSupplier, ControllerEndpointsSupplier controllerEndpointsSupplier,
EndpointMediaTypes endpointMediaTypes, CorsEndpointProperties corsProperties,
WebEndpointProperties webEndpointProperties) {
List<ExposableEndpoint<?>> allEndpoints = new ArrayList<>();
Collection<ExposableWebEndpoint> webEndpoints = webEndpointsSupplier.getEndpoints();
allEndpoints.addAll(webEndpoints);
allEndpoints.addAll(servletEndpointsSupplier.getEndpoints());
allEndpoints.addAll(controllerEndpointsSupplier.getEndpoints());
EndpointMapping endpointMapping = new EndpointMapping(webEndpointProperties.getBasePath());
return new WebMvcEndpointHandlerMapping(endpointMapping,
webEndpoints,
endpointMediaTypes,
corsProperties.toCorsConfiguration(),
new EndpointLinksResolver(allEndpoints, webEndpointProperties.getBasePath()),
true);
}
#Bean
DispatcherServletPath dispatcherServletPath() {
return () -> WebInitializer.APPLICATION_ROOT;
}
}
The example is easy to run directly from maven jetty plugin (mvn jetty:run-war).
<plugin>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>11.0.13</version>
</plugin>
you have made the mistake by not introducing the #springboot annotation in your code.When you add #springboot ot will consider as boot program by the compiler automatically and addd the required dependency file for it and your actuator dependency file
I am tryinging to configure spring data boot sand ES project
in my pom.xml i have :
#Configuration
#EnableElasticsearchRepositories(basePackages = "com.yoyo.elastic.repository")
public class ElasticConfiguration {
#Bean
public NodeBuilder nodeBuilder() {
return new NodeBuilder();
}
#Bean
public ElasticsearchOperations elasticsearchTemplate() throws IOException {
File tmpDir = File.createTempFile("elastic", Long.toString(System.nanoTime()));
System.out.println("Temp directory: " + tmpDir.getAbsolutePath());
final Client client = nodeBuilder().local(true).node().client();
return new ElasticsearchTemplate(client);
}
}
in my pom xml I have this dep :
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>
which should supplay the driver but i keep on getting :
Description:
Cannot determine embedded database driver class for database type NONE
Action:
If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).
I had the same issue when trying to run some exercises with Spring Boot and ElasticSearch.
Right now I figured out that if you have the
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
Alongside spring-boot-starter-data-elasticsearch and don't add additional config classes (where you would configure the DataSource) spring boot will complain.
Other solution would be to actually add a datasource property to application.properties and configure standalone database (like H2)
I tried to change my registration server from "Eureka" to "Consul" and also Consul as my config server. Service discovery with Consul is a success.But I can't understand how to get key/value pair option to bootstrap my application. Is there any possible way I can do that?
I use spring boot with below dependancies
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
and this is my spring boot app ConsuleDemoApplication.class
#EnableDiscoveryClient
#SpringBootApplication
#RestController
public class ConsuleDemoApplication {
#RequestMapping("/")
public String home() {
return "Hello world";
}
public static void main(String[] args) {
SpringApplication.run(ConsuleDemoApplication.class, args);
}
}
and my bootstrap.yml is
spring:
cloud:
consul:
discovery:
healthCheckInterval: 15s
instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}
application:
name: consul_demo
spring boot configuration are ok. then go to consul ui using localhost:8500 and select key/value and add key value like below
then create it.then create configuration are like below
then restart your springboot application. your port change to 8084.
note: you can use YMAL or GIT2consul for more configuration