question: I use spring cloud eureka in springboot project, when the project is starting,it sometimes(This mistake doesn't happen every time) appear java.util.ConcurrentModificationException such as follows。

I guess it may error with spring-cloud-starter-netflix-eureka-client

my project version as follows:

1 springboot: 2.3.2.RELEASE

2 spring-cloud: Hoxton.SR6

3 spring-cloud-starter-netflix-eureka-client: 2.2.3.RELEASE

the error log file show follow:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.cloud.netflix.archaius.ArchaiusAutoConfiguration': Unsatisfied dependency expressed through field 'externalConfigurations'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'configurableEnvironmentConfiguration' defined in class path resource [org/springframework/cloud/netflix/archaius/ArchaiusAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cloud.netflix.archaius.ConfigurableEnvironmentConfiguration]: Factory method 'configurableEnvironmentConfiguration' threw exception; nested exception is java.util.ConcurrentModificationException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1420) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:897) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) at com.anta.it.trainee.trainee.business.TraineeBusinessApplication.main(TraineeBusinessApplication.java:25) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'configurableEnvironmentConfiguration' defined in class path resource [org/springframework/cloud/netflix/archaius/ArchaiusAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cloud.netflix.archaius.ConfigurableEnvironmentConfiguration]: Factory method 'configurableEnvironmentConfiguration' threw exception; nested exception is java.util.ConcurrentModificationException at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:655) at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:635) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1336) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1176) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:556) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1525) at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1489) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1378) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1265) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1227) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ... 25 common frames omitted Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cloud.netflix.archaius.ConfigurableEnvironmentConfiguration]: Factory method 'configurableEnvironmentConfiguration' threw exception; nested exception is java.util.ConcurrentModificationException at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:650) ... 41 common frames omitted Caused by: java.util.ConcurrentModificationException: null at java.util.Hashtable$Enumerator.next(Hashtable.java:1387) at org.apache.commons.configuration.MapConfiguration$1.entrySet(MapConfiguration.java:268) at java.util.AbstractMap.containsKey(AbstractMap.java:144) at org.apache.commons.configuration.MapConfiguration.containsKey(MapConfiguration.java:212) at com.netflix.config.ConcurrentCompositeConfiguration.getProperty(ConcurrentCompositeConfiguration.java:530) at com.netflix.config.ConfigurationManager.setDirect(ConfigurationManager.java:220) at com.netflix.config.ConfigurationManager.install(ConfigurationManager.java:144) at org.springframework.cloud.netflix.archaius.ArchaiusAutoConfiguration.addArchaiusConfiguration(ArchaiusAutoConfiguration.java:189) at org.springframework.cloud.netflix.archaius.ArchaiusAutoConfiguration.configureArchaius(ArchaiusAutoConfiguration.java:162) at org.springframework.cloud.netflix.archaius.ArchaiusAutoConfiguration.configurableEnvironmentConfiguration(ArchaiusAutoConfiguration.java:112) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ... 42 common frames omitted

Comment From: spencergibb

Does it happen with the latest Hoxton?

Comment From: Lixianshengchao

Does it happen with the latest Hoxton?

Does it happen with the latest Hoxton? My project depeny on Spring Cloud Hoxton.SR6 ，it is not the latest Hoxtom

Comment From: spencergibb

Please try with the latest hoxton release

Comment From: Lixianshengchao

Please try with the latest hoxton release

in my project ,I depeny on the maven

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

the default version is 2.2.3.RELEASE, although I replace the lastest spring-cloud-starter-netflix-eureka-client version , the error may appear sometimes

Comment From: Lixianshengchao

I finally dependent on the maven exclude the archaius as follows,it does't again the error once the project starting.

<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <exclusions>
                <exclusion>
                    <artifactId>spring-cloud-starter-netflix-archaius</artifactId>
                    <groupId>org.springframework.cloud</groupId>
                </exclusion>
                <exclusion>
                    <artifactId>spring-cloud-netflix-archaius</artifactId>
                    <groupId>org.springframework.cloud</groupId>
                </exclusion>
            </exclusions>
        </dependency>

I guess my project may be dependent on multiple archaius component,and they conflict

Comment From: Lixianshengchao

My colleague solution this problem set the system property in the BootApplication as follows: System.setProperty("sun.nio.ch.bugLevel", "info");

Comment From: OlgaMaciaszek

Closing as a workaround has been provided.