事故起源于一个原本运行良好的应用，在重启后出现错误。尽管在开发电脑和其他服务器上应用启动正常，但是在某一台服务器上仍然无法正常启动。具体的错误信息如下：
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.5.2)
2023-03-28 08:01:02.312 INFO 1 --- [kground-preinit] o.h.validator.internal.util.Version : HV000001: Hibernate Validator 6.2.0.Final
2023-03-28 08:01:02.349 INFO 1 --- [ main] c.r.push.NotificationServiceApplication : Starting NotificationServiceApplication v0.0.1-SNAPSHOT using Java 1.8.0_212 on localhost with PID 1 (/javafm-notification-service.jar started by root in /)
2023-03-28 08:01:02.349 INFO 1 --- [ main] c.r.push.NotificationServiceApplication : No active profile set, falling back to default profiles: default
2023-03-28 08:01:03.737 INFO 1 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Multiple Spring Data modules found, entering strict repository configuration mode!
2023-03-28 08:01:03.740 INFO 1 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data Redis repositories in DEFAULT mode.
2023-03-28 08:01:03.792 INFO 1 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 34 ms. Found 0 Redis repository interfaces.
2023-03-28 08:01:04.539 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 9112 (http)
2023-03-28 08:01:04.554 INFO 1 --- [ main] o.a.coyote.http11.Http11NioProtocol : Initializing ProtocolHandler ["http-nio-9112"]
2023-03-28 08:01:04.554 INFO 1 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2023-03-28 08:01:04.554 INFO 1 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.48]
2023-03-28 08:01:04.644 INFO 1 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2023-03-28 08:01:04.644 INFO 1 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2158 ms
2023-03-28 08:01:04.713 INFO 1 --- [ main] com.javafm.push.filter.TokenFilter : 初始化过滤器[TokenFilter]
2023-03-28 08:01:05.015 WARN 1 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mailSendConsumer': Unsatisfied dependency expressed through field 'redisTemplate'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'stringRedisTemplate' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/RedisAutoConfiguration.class]: Unsatisfied dependency expressed through method 'stringRedisTemplate' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'redisConnectionFactory' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Unsatisfied dependency expressed through method 'redisConnectionFactory' parameter 1; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'lettuceClientResources' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.ExceptionInInitializerError
2023-03-28 08:01:05.018 INFO 1 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2023-03-28 08:01:05.019 INFO 1 --- [ main] com.javafm.push.filter.TokenFilter : 注销过滤器[TokenFilter]
2023-03-28 08:01:05.036 INFO 1 --- [ main] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2023-03-28 08:01:05.058 ERROR 1 --- [ main] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mailSendConsumer': Unsatisfied dependency expressed through field 'redisTemplate'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'stringRedisTemplate' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/RedisAutoConfiguration.class]: Unsatisfied dependency expressed through method 'stringRedisTemplate' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'redisConnectionFactory' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Unsatisfied dependency expressed through method 'redisConnectionFactory' parameter 1; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'lettuceClientResources' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.ExceptionInInitializerError
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:660)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1413)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:338)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332)
at com.javafm.push.NotificationServiceApplication.main(NotificationServiceApplication.java:63)
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.loader.MainMethodRunner.run(MainMethodRunner.java:49)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:108)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'stringRedisTemplate' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/RedisAutoConfiguration.class]: Unsatisfied dependency expressed through method 'stringRedisTemplate' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'redisConnectionFactory' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Unsatisfied dependency expressed through method 'redisConnectionFactory' parameter 1; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'lettuceClientResources' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.ExceptionInInitializerError
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:800)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:541)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1334)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:657)
... 28 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'redisConnectionFactory' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Unsatisfied dependency expressed through method 'redisConnectionFactory' parameter 1; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'lettuceClientResources' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.ExceptionInInitializerError
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:800)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:541)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1334)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300)
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887)
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791)
... 41 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'lettuceClientResources' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.ExceptionInInitializerError
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:486)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1334)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300)
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887)
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791)
... 55 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.ExceptionInInitializerError
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653)
... 69 common frames omitted
Caused by: java.lang.ExceptionInInitializerError: null
at io.netty.resolver.dns.UnixResolverDnsServerAddressStreamProvider.parseSilently(UnixResolverDnsServerAddressStreamProvider.java:80)
at io.netty.resolver.dns.DnsServerAddressStreamProviders$DefaultProviderHolder$1.provider(DnsServerAddressStreamProviders.java:141)
at io.netty.resolver.dns.DnsServerAddressStreamProviders$DefaultProviderHolder$1.<init>(DnsServerAddressStreamProviders.java:120)
at io.netty.resolver.dns.DnsServerAddressStreamProviders$DefaultProviderHolder.<clinit>(DnsServerAddressStreamProviders.java:118)
at io.netty.resolver.dns.DnsServerAddressStreamProviders.unixDefault(DnsServerAddressStreamProviders.java:107)
at io.netty.resolver.dns.DnsServerAddressStreamProviders.platformDefault(DnsServerAddressStreamProviders.java:103)
at io.netty.resolver.dns.DnsNameResolverBuilder.<init>(DnsNameResolverBuilder.java:60)
at io.lettuce.core.resource.AddressResolverGroupProvider$DefaultDnsAddressResolverGroupWrapper.<clinit>(AddressResolverGroupProvider.java:56)
at io.lettuce.core.resource.AddressResolverGroupProvider.<clinit>(AddressResolverGroupProvider.java:35)
at io.lettuce.core.resource.DefaultClientResources.<clinit>(DefaultClientResources.java:112)
at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration.lettuceClientResources(LettuceConnectionConfiguration.java:69)
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)
... 70 common frames omitted
Caused by: java.lang.IllegalArgumentException: cannot use an unresolved DNS server address: [fe80::5%eth0]:53
at io.netty.resolver.dns.DnsServerAddresses.sanitize(DnsServerAddresses.java:175)
at io.netty.resolver.dns.DnsServerAddresses.sequential(DnsServerAddresses.java:67)
at io.netty.resolver.dns.DefaultDnsServerAddressStreamProvider.<clinit>(DefaultDnsServerAddressStreamProvider.java:107)
... 86 common frames omitted
最初怀疑是因为 Redis 没有正确读取配置文件，导致初始化失败。但是随后发现错误信息中包含了“cannot use an unresolved DNS server address”这句话，提示存在 DNS 解析错误。尽管最初的反应是进行 DNS 解析测试，但是测试结果却表明 DNS 解析正常。另外，在 Redis 配置文件中使用的是 IP 地址而不是域名，因此 DNS 解析问题应该不是出现在此处。
随后在错误信息中发现了一个奇怪的地址（fe80::5%eth0），它既像是网卡名，又像是 IPv6 地址。于是我用 ip addr 查看了网络地址和服务器的 DNS 配置，最终在 /etc/resolv.conf 文件中，发现了与报错一样的地址。
/etc/resolv.conf 文件的内容如下：
# Generated by NetworkManager
nameserver 192.168.118.245
# nameserver fe80::5%eth0
nameserver fd00:7860:5b6b:277c:7a60:5bff:fe6b:277c
于是我将错误的 DNS 解析服务器地址注释掉后，应用程序得以成功启动，不再报错。