I am using Spring Boot with Eureka and it works really good. But since a few hours, I wanted to detect offline Eureka instances/clients more quickly and I found no good documentation about Eureka's configuration properties. And I'm not even sure if it's possible because Eureka seems to presume that clients send their updates every 30 seconds.
I started to deactivate self-preservation mode and to increase the speed of renewal and interval updates and lower expiration durations but my Eureka server still needs two minutes to discover its offline clients.
After changing the renewal percent threshold the Eureka server didn't remove offline clients ever.
Is there any way to detect offline Eureka clients more quickly?
Server configuration:
eureka:
client:
registerWithEureka: false
fetchRegistry: false
server:
enableSelfPreservation: false
eviction-interval-timer-in-ms: 10000
response-cache-update-interval-ms: 5000
Client configuration:
eureka:
client:
serviceUrl:
defaultZone: ${EUREKA_URI:http://localhost:8761/eureka}
healthcheck:
enabled: true
instance:
lease-renewal-interval-in-seconds: 5
lease-expiration-duration-in-seconds: 15
edit:
Even health check url is not called more often. It is still called every 30 seconds.
Did you check Ribbon configuration. Ribbon can cache servers configuration upfront during startup and make use of it when Eureka-sever is down. Please check if ribbon is enabled on eureka-client app
The correct option to change the schedule was:
eureka.client.instance-info-replication-interval-seconds
Related
I was going through a tutorial and I came across with this config in .yml file.
eureka:
client:
registerWithEureka: false
fetchRegistry: false
server:
waitTimeInMsWhenSyncEmpty: 0
Here, what exactly is the purpose of "waitTimeInMsWhenSyncEmpty"? Also what does "fetchRegistry" flag say?
Thank you.
eureka:
client:
registerWithEureka: false
fetchRegistry: false
server:
waitTimeInMsWhenSyncEmpty: 0
Basically above three lines tells:
this instance to not register itself with the Eureka instance it finds, because that instance is.. itself.
Source :Spring Doc
Below are the individual statement level meanings:
Configuration tells eureka(client) to gets the registration information from the eureka server registry, the default is true
eureka:
client:
fetchRegistry: false
Configuration tells when the eureka server is started, you cannot wait for the instance registration information from the peer node. How long should it wait?source
eureka:
client:
server:
waitTimeInMsWhenSyncEmpty: 0
Usage : By default euraka server could act as both client and server.This is useful when we run multiple eureka servers to face SPOF issues.In this case , eureka could register both other microservice instances and naming server instances.
I have all clients (eureka instances) running with https. I have configured my eureka clients as mentioned in https://cloud.spring.io/spring-cloud-netflix/2.2.x/reference/html/#registering-a-secure-application
Everything in the config shown below works except the port information. Note that the config is clearly missing port information for all URLs, viz, statusPageUrl, healthCheckUrl and homePageUrl.
eureka:
instance:
nonSecurePortEnabled: false
securePortEnabled: true
**statusPageUrl: https://${eureka.hostname}/info**
**healthCheckUrl: https://${eureka.hostname}/health**
**homePageUrl: https://${eureka.hostname}/**
client:
serviceUrl:
defaultZone: ${EUREKA_SERVER}
healthcheck:
enabled: true
Since I have configured random port, I cannot hard code the port information in above urls. Could anyone please help me on this?
server:
port: 0
(It is basically two Eureka server and three Eureka client microservices)
I want to remove the following message:
EMERGENCY! EUREKA MAY BE INCORRECTLY CLAIMING INSTANCES ARE UP WHEN THEY'RE NOT. RENEWALS ARE LESSER THAN THRESHOLD AND HENCE THE INSTANCES ARE NOT BEING EXPIRED JUST TO BE SAFE.
error image
Eureka Server1:
spring.application.name=ms-service-discovery-1
server.port=8761
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
eureka.server.enableSelfPreservation= true
eureka.instance.leaseRenewalIntervalInSeconds=1
eviction-interval-timer-in-ms: 1000
eureka.server.wait-time-in-ms-when-sync-empty: 1000
eureka.server.responseCacheUpdateIntervalMs: 1000
Eureka Server2:
spring.application.name=ms-service-discovery-2
server.port=8761
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
eureka.server.enableSelfPreservation= true
eureka.instance.leaseRenewalIntervalInSeconds=1
eviction-interval-timer-in-ms: 1000
eureka.server.wait-time-in-ms-when-sync-empty: 1000
It's due to Eureka's self-preservation mode. Eureka servers will stop the eviction of all instances if the number of heartbeats renewals is below the expected threshold. The warning in your Eureka servers shows this situation happened.
Please try to adjust the below property. 85% is the default value. First, just try to lower the below property like 0.50
eureka.renewalPercentThreshold=0.85
Alternatively, you can disable self-preservation mode with the below property.
eureka.enableSelfPreservation=false
Note
Basically, all Eureka client unregister itself when it shuts down. If it unregisters itself successfully, the above problem will not happen.
Unfortunately, sometimes the Spring Cloud based Eureka client doesn't unregister itself when it shuts down and the symptom is different based on the Spring Cloud version. Dalston and Edgware release unregister itself well in most cases. But Finchley releases seem not to unregister itself now.
Also, you start to run MANY instances in your Eureka environment, the above message will disappear because just one or two instances shutdown will not reach the threshold.
You can find more information about self-preservation mode here
I don't know whether it is possible or not. I want to know whether I can enroll one microservice at two different eureka server at once.
I have one MS let say API-GATEWAY:
I want to enrol it on two different eureka registry server running on 8761 and 8762.
for that I write:
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/ , http://localhost:8762/eureka/
registry-fetch-interval-seconds: 1000
instance:
hostname: api-gateway
prefer-ip-address: true
lease-renewal-interval-in-seconds: 5000000
lease-expiration-duration-in-seconds: 5000000
First up all tell me is it possible or not?
If yes, what property should I use to achieve the objectives?
You can have only one defaultZone. You need peer replication. So that your 8761/eureka is synchronized with 8762/eureka. When the application is registered to 8761 it is also available in 8762. To do this see #spencergibb answer here.
I’m having a bit of trouble getting Turbine to work in Spring Cloud. In a nutshell, I can’t determine how to configure it to aggregate circuits from more than one application at a time.
I have 6 separate services, a eureka server, and a turbine server running in standalone mode. I can see from my Eureka server that all of the services are registered, including turbine. My turbine server is up and running, and I can see its /hystrix page without issue. But when I try to use it to examine turbine.stream, I only see the FIRST server that is listed in turbine.appConfig, the rest are ignored.
This is my Turbine server’s application.yml, or at least the relevant parts:
---
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8010/eureka/
server:
port: 8030
info:
component: Turbine
turbine:
clusterNameExpression: new String(“default”)
appConfig: sentence,subject,verb,article,adjective,noun
management:
port: 8990
When I run this and access the hystrix dashboard on my turbine instance, asking for the turbine.stream, the ONLY circuit breakers listed in the output are for the first service listed in appConfig, the “sentence” service in this case. Curiously, if I re-arrange the order of these services and put another one first (like “noun”), I see only the circuits for THAT service. Only the first service in the list is displayed.
I’ll admit to being a little confused on some of the terminology, like streams, clusters, etc., so I could be missing some basic concept here, but my understanding is that Turbine could digest streams from more than one service and aggregate them in a single display. Suggestions would be appreciated.
I don't have enough reputation to comment, so I have to write this in an answer :)
I had the exactly same problem:
There are two services "test-service" and "other-service", each with it's own working hystrix-stream
and there is one Turbine-Application, which is configured like this:
turbine:
clusterNameExpression: new String("default")
appConfig: test-service,other-service
All of my services are running on my local machine.
Result is: My Hystrix-Dashboard just shows the metrics from "test-service".
Reason:
It seems to be, that a Turbine-Client which is configured the described way doesn't handle multiple services when they are running at the same host.
This is explained here:
https://github.com/Netflix/Hystrix/issues/117#issuecomment-14262713
Turbine maintains state of all these instances in order to maintain persistent connections to them and it does rely on the "hostname" and if the host name is the same then it won't instantiate a new connection to that same server (on a different port).
So the main point is, that all of your services must be registered with different hostnames. How you could do this on your local machine is described below.
UPDATE 2015-06-12/2016-01-23: Workaround for local testing
Change your hostfile:
# ...
127.0.0.1 localhost
127.0.0.1 localdomain1
127.0.0.1 localdomain2
# ...
127.0.0.1 localdomainx
And then set the hostname for your clients each to a different domain-entry like this:
application.yml:
eureka:
instance:
hostname: localdomainx