From the spring doc, I see we can have peer eureka server together, so for Eureka1, in application.yml, I can have:
spring:
profiles: peer1
eureka:
instance:
hostname: peer1
client:
serviceUrl:
defaultZone: http://peer2/eureka/
And in Eureka Server 2, I can have:
spring:
profiles: peer2
eureka:
instance:
hostname: peer2
client:
serviceUrl:
defaultZone: http://peer1/eureka/
Now these two eureka servers are aware each other, it is good.
BUT, now in configuring client, when they register again Eureka, how to do this?
In my client application, I have:
eureka:
instance:
hostname: ${host.instance.name:localhost}
nonSecurePort: ${host.instance.port:8080}
leaseRenewalIntervalInSeconds: 5 #default is 30, recommended to keep default
metadataMap:
instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}
client:
serviceUrl:
defaultZone: http://(eurekaServerHost):8761/eureka/
server:
port: ${host.instance.port:8080}
So now my question is shall I use peer1 or peer2 as EurekaServerHost in the client application.yml?
Thanks
Use a comma separated list of peers in eureka.client.serviceUrl.defaultZone.
eureka.client.serviceUrl.defaultZone=http://<peer1host>:<peer1port>/eureka,http://<peer2host>:<peer2port>/eureka
Related
I have a Eureka Server running on default localhost host and port 8761, so i tried to change this default configuration in this way:
server:
port: 6000
servlet:
context-path: /myeureka
eureka:
client:
register-with-eureka: false
fetch-registry: false
But in this way i can't access eureka dashboard, just using default configuration:
server:
port: 8761
eureka:
client:
register-with-eureka: false
fetch-registry: false
In my client same thing occurrs, i can't point to another eureka server different from default (localhost:8761), see my configuration:
server:
port: 7000
servlet:
context-path: /client-eureka
spring:
application:
name: client-eureka
eureka:
instance:
prefer-ip-address: true
client:
eureka-server-port: 6000
eureka-server-u-r-l-context: /myeureka
Lookin in client log i got the following:
2018-09-01 09:19:37.175 INFO 4931 --- [ main] c.n.eureka.cluster.PeerEurekaNodes : Replica node URL: http://localhost:8761/eureka/
No matter what port or host i configure in client, always try to reach the default.
Important:
I'm using eureka in this version: https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-netflix-eureka-server/2.0.1.RELEASE
I used the same dependency version as yours and cannot find the config path server.servlet.contextpath
Instead, you can use either server.servlet-path or server.context-path
With each of the server configuration, you need to update your client application.yml file too. Remember that /eureka is the default REST endpoint used to register Eureka client with Eureka server
Case 1: Use server.servlet-path
Eureka Server:
server:
port: 7000
servlet-path: /myeureka
eureka:
client:
register-with-eureka: false
fetch-registry: false
Eureka Client:
spring:
application:
name: spring-cloud-eureka-client
server:
port: 0
eureka:
client:
service-url:
defaultZone: ${EUREKA_URI:http://localhost:7000/eureka}
instance:
preferIpAddress: true
Case 2: Use server.context-path
Eureka Server:
server:
port: 7000
context-path: /myeureka
eureka:
client:
register-with-eureka: false
fetch-registry: false
Eureka Client:
spring:
application:
name: spring-cloud-eureka-client
server:
port: 0
eureka:
client:
service-url:
defaultZone: ${EUREKA_URI:http://localhost:7000/myeureka/eureka}
instance:
preferIpAddress: true
Updated answer:
Because server.servlet-path and server.context-path were deprecated, eureka server will be configured as following:
server:
port: 7000
servlet:
context-path: /myeureka
eureka:
client:
register-with-eureka: false
fetch-registry: false
Eureka client application.yml will be kept as in Case 2.
I am trying to setup a eureka cluster which comprise of there servers. (my setup is on local machine)
Configurations for each eureka server as below:
server1:
server:
port: 8764
eureka:
instance:
metadataMap:
instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}
client:
registerWithEureka: true
fetchRegistry: true
# availabilityZones: zone1,zone1,zone1
server:
waitTimeInMsWhenSyncEmpty: 0
serviceUrl:
defaultZone: http://localhost:8762/eureka/,http://localhost:8763/eureka/,http://localhost:8764/eureka/
server2:
server:
port: 8762
eureka:
instance:
metadataMap:
instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}
client:
registerWithEureka: true
fetchRegistry: true
server:
waitTimeInMsWhenSyncEmpty: 0
serviceUrl:
defaultZone: http://localhost:8762/eureka/,http://localhost:8763/eureka/,http://localhost:8764/eureka/
server3:
server:
port: 8763
eureka:
instance:
metadataMap:
instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}
client:
registerWithEureka: true
fetchRegistry: true
server:
waitTimeInMsWhenSyncEmpty: 0
serviceUrl:
defaultZone: http://localhost:8762/eureka/,http://localhost:8763/eureka/,http://localhost:8764/eureka/
each server is peering to each others, so registration info will be replicated among servsers.
But, when I checked the logs server, it always throw exception as beblow:
I also checked dashboard of eureka server and it shown as below:
I dont know why the registered replicas (http://localhost:8761/eureka/) did not change even I have configured
serviceUrl:
defaultZone: http://localhost:8762/eureka/,http://localhost:8763/eureka/,http://localhost:8764/eureka/
I have setup a micro services and register to the eureka cluster, but for somehow the service info only is registered on one of eureak server, I am expecting that info also replicated to others as well
is there anyone suffering from same issue, I have been trying searching a lot but could not find the right answer for my case.
High appreicate for any advice?
I have found the issues. I have put serviceUrl in wrong section (server).
it should be in the client part.
server:
port: 8763
eureka:
instance:
metadataMap:
instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}
client:
registerWithEureka: false
fetchRegistry: false
serviceUrl:
defaultZone: http://localhost:8762/eureka/,http://localhost:8763/eureka/,http://localhost:876
server:
waitTimeInMsWhenSyncEmpty: 0
I spent all day trying to make Zuul + Eureka work together, but I hasn't been lucky with that. Zuul alone, without Eureka, works fine. I've tried a lot of different configurations like this one, which says that all I have to do is turn Zull in an Eureka client (by using #EnableDiscoveryClient at root application class).
My setup is very simple: it consists of a service:8080 (service 1), Zuul:9000 and Eureka:8761.
All the approaches I've tried using Eureka gave me the same error when I tried to access service 1 using Zull (http://localhost:9000/service1 in this case):
com.netflix.zuul.exception.ZuulException: Forwarding error
(...)
com.netflix.client.ClientException: Load balancer does not have available server for client: service1
Service 1 is working fine (I can access it directly from the browser address bar http://localhost:8080) and Eureka shows both Zull and Service 1 correctly registered:
The apps are configured like:
Service 1 (bootstrap.yml):
spring:
application:
name: service1
Service 1 (application.yml):
eureka:
instance:
leaseRenewalIntervalInSeconds: 1
leaseExpirationDurationInSeconds: 2
client:
serviceUrl:
defaultZone: http://127.0.0.1:8761/eureka/
Zuul:
ribbon:
eureka:
enabled: false
eureka:
instance:
leaseRenewalIntervalInSeconds: 1
leaseExpirationDurationInSeconds: 2
client:
serviceUrl:
defaultZone: http://127.0.0.1:8761/eureka/
healthcheck:
enabled: true
server:
port: 9000
Eureka:
server:
port: 8761
eureka:
client:
register-with-eureka: false
fetch-registry: false
logging:
level:
com:
netflix:
eureka: OFF
discovery: OFF
Zuul Annotations at root application class:
#EnableZuulProxy
#EnableDiscoveryClient
Am I missing any important point?
We are running in a peer to peer Eureka configuration. See below for the configuration.
So when the services are started, they register to 10.202.10.95 (the primary) and we see them there with none showing on 10.202.10.97 (the secondary)
If we kill 10.202.10.95 (the primary) then we see them show up on 10.202.10.97 (the secondary eureka).
If we restart 10.202.10.95 (which was the primary), we see the services show up on 10.202.10.95 and also on 10.202.10.97. So services are visible on both eureka servers
If we restart 10.202.10.97 (the secondary), the services vanish and are just visible on the primary (10.202.10.95)
Case 3 is unexpected to me. Is this a case of improper peer to peer Eureka configuration?
The eureka configuration is as follows: (we point these 2 instances to each other in a peer to peer configuration)
spring:
profiles: api06-prod-int-discoveryserver # 10.202.10.95 eureka host
eureka:
client:
registerWithEureka: true
fetchRegistry: true
serviceUrl:
defaultZone: http://10.202.10.97:8761/eureka/
---
spring:
profiles: api05-prod-int-discoveryserver # 10.202.10.97 eureka host
eureka:
client:
registerWithEureka: true
fetchRegistry: true
serviceUrl:
defaultZone: http://10.202.10.95:8761/eureka/
Each service has its configuration to eureka set like this: (we point to both instances with x.x.x.95 being the primary)
eureka:
# these are settings for the client that gets services
client:
# enable these two settings if you want discovery to work
registerWithEureka: true
fetchRegistry: true
serviceUrl:
defaultZone: http://10.202.10.95:8761/eureka/,http://10.202.10.97:8761/eureka/
So, following some other posts and Spencer's response I checked and my configuration was incorrect. After I changed it, it responds correctly.
This is the Eureka settings. I run 2 eureka servers, one with profile peer1 and the other with profile peer2.
---
spring:
profiles: peer1 # not standalone
server:
port: 8761
eureka:
instance:
hostname: peer2
leaseRenewalIntervalInSeconds: 3
client:
serviceUrl:
defaultZone: http://localhost:8762/eureka/
---
spring:
profiles: peer2 # not standalone
server:
port: 8762
eureka:
instance:
hostname: peer1
leaseRenewalIntervalInSeconds: 3
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
server:
waitTimeInMsWhenSyncEmpty: 0
The Service that I have connecting is configured like this
eureka:
client:
registerWithEureka: true
fetchRegistry: true
serviceUrl:
defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/
instance:
statusPageUrlPath: /${info.app.name}/manage/info
homePageUrlPath: /${info.app.name}/manage
healthCheckUrlPath: /${info.app.name}/manage/health
preferIpAddress: true
After I run my service, I can see it connect to both discovery services and if I kill either then it is visible on the other discovery service.
I'm prototyping a set of Spring Cloud + Netflix OSS applications and have run into trouble with Eureka. In our setup, we have a Spring Cloud Config Server + Eureka Server, and then 2 modules that utilize that server component for bootstrapping and service discovery.
The problem I run into is that if I spin up 2 instances of the Eureka Server and try to pair them (based on the Two Peer Aware Eureka Servers in the docs) they don't synchronize with each other. See configs below and/or the code on GitHub.
Essentially, Peer1 starts up and looks fine. Peer2 will startup and look fine, with both peers showing each other in the services. However, if the "UserService" module spins up and registers itself with Peer1, Peer2 will never see it. If we then spin up the "Web" module pointing to Peer2, it can never resolve the UserService. They basically act in isolation.
I've tried several combinations of setting the serviceUrl both on the server and the instance of the Eureka servers but to no avail. Am I just configuring things wrong?
Peer 1 / default config:
server:
port: 8888
eureka:
dashboard:
path: /dashboard
instance:
hostname: peer1
leaseRenewalIntervalInSeconds: 3
client:
serviceUrl:
defaultZone: ${eureka.server.serviceUrl:http://localhost:${server.port}/eureka/}
server:
serviceUrl:
defaultZone: http://localhost:${server.port}/eureka/
peer2: http://peer2/eureka/
waitTimeInMsWhenSyncEmpty: 0
spring:
application:
name: demo-config-service
profiles:
active: native
# required for Spring Cloud Bus
rabbitmq:
host: ${DOCKER_IP:192.168.59.103}
port: 5672
username: guest
password: guest
virtualHost: /
cloud:
config:
server:
prefix: /configs
native:
searchLocations: /Users/dave/workspace/oss/distributed-spring/modules/config-server/src/main/resources/testConfigs
# git :
# uri: https://github.com/joshlong/microservices-lab-configuration
Peer 2 config:
server:
port: 8889
eureka:
dashboard:
path: /dashboard
instance:
hostname: peer2
leaseRenewalIntervalInSeconds: 3
client:
serviceUrl:
defaultZone: ${eureka.server.serviceUrl:http://localhost:${server.port}/eureka/}
server:
serviceUrl:
defaultZone: http://localhost:8888/eureka/
peer1: http://peer1/eureka/
waitTimeInMsWhenSyncEmpty: 0
spring:
application:
name: demo-config-service
profiles:
active: native
# required for Spring Cloud Bus
rabbitmq:
host: ${DOCKER_IP:192.168.59.103}
port: 5672
username: guest
password: guest
virtualHost: /
cloud:
config:
server:
prefix: /configs
native:
searchLocations: /Users/dave/workspace/oss/distributed-spring/modules/config-server/src/main/resources/testConfigs
# git :
# uri: https://github.com/joshlong/microservices-lab-configuration
There were a few problems. The defaultZone needs to be in the client section as noted in the docs. The defaultZone url needs the port.
/etc/hosts
127.0.0.1 peer1
127.0.0.1 peer2
Peer 1 Config (Partial)
eureka:
instance:
hostname: peer1
leaseRenewalIntervalInSeconds: 3
client:
serviceUrl:
defaultZone: http://peer2:8889/eureka/
Peer 2 Config (Partial)
eureka:
dashboard:
path: /dashboard
instance:
hostname: peer2
leaseRenewalIntervalInSeconds: 3
client:
serviceUrl:
defaultZone: http://peer1:8888/eureka/
server:
waitTimeInMsWhenSyncEmpty: 0
User service config (Partial) Config port was wrong.
spring:
application:
name: user-service
cloud:
config:
uri: http://localhost:8888/configs
You can see user-service replicated to both peer1 and peer2. I can post a PR to your code if you want.
Peer 1
Peer 2
#spencergibb's didn't mention why this hack-ish workaround is required. There is a gotcha with running more than one Eureka server on the same host. Netflix code (com.netflix.eureka.cluster.PeerEurekaNodes.isThisMyUrl) filters out the peer URLs that are on the same host. This may have been done to prevent the server registering as its own peer (I’m guessing here) but because they don’t check for the port, peer awareness doesn’t work unless the Eureka hostnames in the eureka.client.serviceUrl.defaultZone are different. The hacky workaround for this is to define unique hostnames and then map them to 127.0.0.1 in the /etc/hosts file (or its Windows equivalent).
I've created a blog post with the details of Eureka here, that fills in some missing detail from Spring doc or Netflix blog. It is the result of several days of debugging and digging through source code.