With this meatdata, and multiple service instances deployed on
With this metadata, and multiple service instances deployed on
localhost, the random value will kick in there to make the instance
unique. In Cloudfoundry the `spring.application.instance_id` will be
populated automatically in a Spring Boot Actuator application, so the
...
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@@ -186,12 +186,11 @@ assumptions about the lease renewal period.
[[spring-cloud-eureka-server]]
== Service Discovery: Eureka Server
Example eureka server:
Example eureka server (e.g. using spring-cloud-starter-eureka-server to set up the classpath):
[source,java,indent=0]
----
@Configuration
@EnableAutoConfiguration
@SpringBootApplication
@EnableEurekaServer
public class Application {
...
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@@ -462,9 +461,9 @@ To run the Hystrix Dashboard annotate your Spring Boot main class with `@EnableH
=== Turbine
Looking at an individual instances Hystrix data is not very useful in terms of the overall health of the system. https://github.com/Netflix/Turbine[Turbine] is an application that aggregates all of the relevant `/hystrix.stream` endpoints into a combined `/turbine.stream` for use in the Hystrix Dashboard. Individual instances are located via Eureka. Running Turbine is as simple as annotating your main class with the `@EnableTurbine` annotation. All of the documented configuration properties from https://github.com/Netflix/Turbine/wiki/Configuration-(1.x)[the Turbine 1 wiki] apply. The only difference is that the `turbine.instanceUrlSuffix` does not need the port prepended as this is handled automatically unless `turbine.instanceInsertPort=false`.
Looking at an individual instances Hystrix data is not very useful in terms of the overall health of the system. https://github.com/Netflix/Turbine[Turbine] is an application that aggregates all of the relevant `/hystrix.stream` endpoints into a combined `/turbine.stream` for use in the Hystrix Dashboard. Individual instances are located via Eureka. Running Turbine is as simple as annotating your main class with the `@EnableTurbine` annotation (e.g. using spring-cloud-starter-turbine to set up the classpath). All of the documented configuration properties from https://github.com/Netflix/Turbine/wiki/Configuration-(1.x)[the Turbine 1 wiki] apply. The only difference is that the `turbine.instanceUrlSuffix` does not need the port prepended as this is handled automatically unless `turbine.instanceInsertPort=false`.
Configuration key `turbine.appConfig` is a list of eureka serviceId's that turbine will use to lookup instances. The turbine stream is then used in the Hystrix dashboard using a url that looks like: `http://my.turbine.sever:8080/turbine.stream?cluster=<CLUSTERNAME>` (the cluster parameter can be omitted if the name is "default"). The `cluster` parameter must match an entry in `turbine.aggregator.clusterConfig`. Value returned from eureka are uppercase, thus we expect this example to work if there is an app registered with Eureka called "customers":
The configuration key `turbine.appConfig` is a list of eureka serviceIds that turbine will use to lookup instances. The turbine stream is then used in the Hystrix dashboard using a url that looks like: `http://my.turbine.sever:8080/turbine.stream?cluster=<CLUSTERNAME>` (the cluster parameter can be omitted if the name is "default"). The `cluster` parameter must match an entry in `turbine.aggregator.clusterConfig`. Values returned from eureka are uppercase, thus we expect this example to work if there is an app registered with Eureka called "customers":
----
turbine:
...
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@@ -473,7 +472,19 @@ turbine:
appConfig: customers
----
The `clusterName` can be customized by a SPEL expression in `turbine.clusterNameExpression`. For example, `turbine.clusterNameExpression=aSGName` would get the cluster name from the AWS ASG name. To use the "default" cluster for all apps you need a string literal expression (with single quotes):
The `clusterName` can be customized by a SPEL expression in `turbine.clusterNameExpression` with root an instance of `InstanceInfo`. The default value is `appName`, which means that the Eureka serviceId ends up as the cluster key (i.e. the `InstanceInfo` for customers has an `appName` of "CUSTOMERS"). A different example would be `turbine.clusterNameExpression=aSGName`, which would get the cluster name from the AWS ASG name. Another example:
----
turbine:
aggregator:
clusterConfig: SYSTEM,USER
appConfig: customers,stores,ui,admin
clusterNameExpression: metadata.cluster
----
In this case, the cluster name from 4 services is pulled from their metadata map, and is expected to have values that include "SYSTEM" and "USER".
To use the "default" cluster for all apps you need a string literal expression (with single quotes):
