java.util.concurrent.TimeoutException: Did not observe any item or terminal signal within 10000ms in 'map' (and no fallback has been configured)

Question

I'm building the Spring Boot Admin code and getting the below error.

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>admin-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>admin-server</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-boot-admin.version>2.3.1</spring-boot-admin.version>
        <spring-cloud.version>2020.0.2</spring-cloud.version>
    </properties>
    <dependencies>
        <!-- Spring Boot Admin -->
        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>spring-boot-admin-starter-server</artifactId>
        </dependency>
        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>spring-boot-admin-server-ui</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        
        <!-- Third-party librairies -->
        <dependency>
            <groupId>org.jolokia</groupId>
            <artifactId>jolokia-core</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>de.codecentric</groupId>
                <artifactId>spring-boot-admin-dependencies</artifactId>
                <version>${spring-boot-admin.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

bootstrap.yml

spring:
  cloud:
    config:
      enabled: true
      uri: http://localhost:9296
      
  application:
    name: admin-server
    
server:
  port: 9090
  
eureka:
  client:
    register-with-eureka: true
    fetch-registry: true
  instance:
    hostname: localhost
    prefer-ip-address: true

AdminServerApplication.java

@SpringBootApplication
@EnableAdminServer
@EnableEurekaClient
public class AdminServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(AdminServerApplication.class, args);
    }

}

Error:

2021-05-04 13:39:12.290  WARN 36752 --- [ctor-http-nio-1] io.netty.resolver.dns.DnsQueryContext    : Received a mismatching DNS response: DatagramDnsResponse(from: /172.30.160.1:53, to: /0:0:0:0:0:0:0:0:56414, 52280, QUERY(0), NoError(0), RD RA)
    DefaultDnsQuestion(XXXXXXXXorg. IN A)
    DefaultDnsRawRecord(XXXXXXXXorg. 171 IN A 4B)
    DefaultDnsRawRecord(OPT flags:0 udp:4096 0B)
2021-05-04 13:39:12.882  INFO 36752 --- [           main] com.example.demo.AdminServerApplication  : Started AdminServerApplication in 6.649 seconds (JVM running for 7.875)
2021-05-04 13:39:17.355  WARN 36752 --- [ctor-http-nio-1] io.netty.resolver.dns.DnsQueryContext    : Received a mismatching DNS response: DatagramDnsResponse(from: /172.30.160.1:53, to: /0:0:0:0:0:0:0:0:56414, 3238, QUERY(0), NoError(0), RD AA RA)
    DefaultDnsQuestion(XXXXXXXXorg. IN CNAME)
    DefaultDnsRawRecord(corp.mastercard.org. 3600 IN SOA 56B)
    DefaultDnsRawRecord(OPT flags:0 udp:4000 0B)
2021-05-04 13:39:22.211  INFO 36752 --- [     parallel-5] d.c.b.a.server.services.StatusUpdater    : Couldn't retrieve status for Instance(id=162455d08d2a, version=0, registration=Registration(name=CONFIG-SERVER, managementUrl=http://XXXXXXXXorg:9296/actuator, healthUrl=http://XXXXXXXXorg:9296/actuator/health, serviceUrl=http://XXXXXXXXorg:9296, source=discovery), registered=true, statusInfo=StatusInfo(status=UNKNOWN, details={}), statusTimestamp=2021-05-04T08:09:12.195Z, info=Info(values={}), endpoints=Endpoints(endpoints={health=Endpoint(id=health, url=http://XXXXXXXXorg:9296/actuator/health)}), buildVersion=null, tags=Tags(values={}))

java.util.concurrent.TimeoutException: Did not observe any item or terminal signal within 10000ms in 'map' (and no fallback has been configured)
    at reactor.core.publisher.FluxTimeout$TimeoutMainSubscriber.handleTimeout(FluxTimeout.java:294) ~[reactor-core-3.4.2.jar:3.4.2]
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    |_ checkpoint ⇢ Request to GET health [DefaultWebClient]
Stack trace:
        at reactor.core.publisher.FluxTimeout$TimeoutMainSubscriber.handleTimeout(FluxTimeout.java:294) ~[reactor-core-3.4.2.jar:3.4.2]
        at reactor.core.publisher.FluxTimeout$TimeoutMainSubscriber.doTimeout(FluxTimeout.java:279) ~[reactor-core-3.4.2.jar:3.4.2]
        at reactor.core.publisher.FluxTimeout$TimeoutTimeoutSubscriber.onNext(FluxTimeout.java:418) ~[reactor-core-3.4.2.jar:3.4.2]
        at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:79) ~[reactor-core-3.4.2.jar:3.4.2]
        at reactor.core.publisher.MonoDelay$MonoDelayRunnable.run(MonoDelay.java:119) ~[reactor-core-3.4.2.jar:3.4.2]
        at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:68) ~[reactor-core-3.4.2.jar:3.4.2]
        at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:28) ~[reactor-core-3.4.2.jar:3.4.2]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_171]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) ~[na:1.8.0_171]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) ~[na:1.8.0_171]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_171]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_171]
        at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_171]

Azoic

Answer 1

I was able to solve this issue. Basically all your microservices should use below configuration. Here prefer-ip-address: true and fetch-registry: true is the key here.

server:
  port: 8002

spring:
  application:
    name: user-service
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test
    username: root
    password: root
    
  jpa:
    generate-ddl: true
    hibernate:
      ddl-auto: create
 
#  zipkin:
#    base-url: http://127.0.0.1:9411/

eureka:
  client:
    register-with-eureka: true
    fetch-registry: true
  instance:
    prefer-ip-address: true
    hostname: localhost
    

Azoic

any explanation, or reason for this ? – Ravens