网上的教程都是2个实例的集群，自己整了一下，三个实例只有前两个可以发现服务，第三个无数据。
下面是配置文件
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server:
port: 8761
spring:
profiles: peer1
eureka:
instance:
hostname: peer1
client:
serviceUrl:
defaultZone: http://peer2:8769/eureka/
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server:
port: 8769
spring:
profiles: peer2
eureka:
instance:
hostname: peer2
client:
serviceUrl:
defaultZone: http://peer3:8669/eureka/
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server:
port: 8669
spring:
profiles: peer3
eureka:
instance:
hostname: peer3
client:
serviceUrl:
defaultZone: http://peer1:8761/eureka/
http://peer1:8769/eureka/，http://peer2:8769/eureka/，http://peer3:8769/eureka/
全配上