两个月前把之前的nexus3迁移到另一台服务器后，当时看所有的jar包和snapshot包都在，就没有管了。今天在上传snapshot时报错如下：
Failed to execute goal org.apache.maven.plugins:maven-deploy-plugin:2.7:deploy-file (default-cli) on project standalone-pom: Failed to retrieve remote metadata xxx:1.0.0-SNAPSHOT/maven-metadata.xml: Could not transfer metadata xxx1.0.0-SNAPSHOT/maven-metadata.xml from/to nexus-snapshots (http://xxxx/repository/maven-snapshots/): Failed to transfer file: http://xxxx/repository/maven-snapshots/xxx/1.0.0-SNAPSHOT/maven-metadata.xml. Return code is: 500 , ReasonPhrase:javax.servlet.ServletException: org.sonatype.nexus.repository.storage.RetryDeniedException: Reached max retries: 8/8.
看上面这个错误消息看不出是什么错误，搜索也基本上搜不出来，只是一个通用的retryDenied异常。
找到nexus日志sonatype-work/nexus3/log看了下，才看到真正的错误。如下：
2019-06-20 08:35:42,187+0800 WARN [qtp118651636-374] *UNKNOWN org.sonatype.nexus.repository.httpbridge.internal.ViewServlet - Failure servicing: GET /repository/maven-snapshots/com/szkj/product/cw-busiz-core/maven-metadata.xml
org.sonatype.nexus.repository.storage.RetryDeniedException: Reached max retries: 8/8
at org.sonatype.nexus.repository.storage.StorageTxImpl.allowRetry(StorageTxImpl.java:224)
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.sonatype.nexus.common.stateguard.SimpleMethodInvocation.proceed(SimpleMethodInvocation.java:53)
at org.sonatype.nexus.common.stateguard.StateGuardAspect$1.invoke(StateGuardAspect.java:69)
at com.sun.proxy.$Proxy198.allowRetry(Unknown Source)
at org.sonatype.nexus.transaction.TransactionalWrapper.proceedWithTransaction(TransactionalWrapper.java:81)
at org.sonatype.nexus.transaction.TransactionInterceptor.invoke(TransactionInterceptor.java:54)
at org.sonatype.nexus.repository.maven.internal.hosted.HostedHandler.doGet(HostedHandler.java:75)
at org.sonatype.nexus.repository.maven.internal.hosted.HostedHandler.handle(HostedHandler.java:61)
at org.sonatype.nexus.repository.view.Context.proceed(Context.java:80)
at org.sonatype.nexus.repository.storage.UnitOfWorkHandler.handle(UnitOfWorkHandler.java:39)
at org.sonatype.nexus.repository.view.Context.proceed(Context.java:80)
at org.sonatype.nexus.repository.view.handlers.ContentHeadersHandler.handle(ContentHeadersHandler.java:44)
at org.sonatype.nexus.repository.view.Context.proceed(Context.java:80)
at org.sonatype.nexus.repository.maven.internal.VersionPolicyHandler.handle(VersionPolicyHandler.java:61)
at org.sonatype.nexus.repository.view.Context.proceed(Context.java:80)
at org.sonatype.nexus.repository.view.handlers.ConditionalRequestHandler.handle(ConditionalRequestHandler.java:72)
at org.sonatype.nexus.repository.view.Context.proceed(Context.java:80)
at org.sonatype.nexus.repository.view.handlers.ExceptionHandler.handle(ExceptionHandler.java:44)
at org.sonatype.nexus.repository.view.Context.proceed(Context.java:80)
at org.sonatype.nexus.repository.security.SecurityHandler.handle(SecurityHandler.java:52)
at org.sonatype.nexus.repository.view.Context.proceed(Context.java:80)
at org.sonatype.nexus.repository.view.handlers.TimingHandler.handle(TimingHandler.java:46)
at org.sonatype.nexus.repository.view.Context.proceed(Context.java:80)
at org.sonatype.nexus.repository.view.Context.start(Context.java:114)
at org.sonatype.nexus.repository.view.Router.dispatch(Router.java:64)
at org.sonatype.nexus.repository.view.ConfigurableViewFacet.dispatch(ConfigurableViewFacet.java:52)
at org.sonatype.nexus.repository.view.ConfigurableViewFacet.dispatch(ConfigurableViewFacet.java:43)
at org.sonatype.nexus.repository.httpbridge.internal.ViewServlet.dispatchAndSend(ViewServlet.java:210)
at org.sonatype.nexus.repository.httpbridge.internal.ViewServlet.doService(ViewServlet.java:172)
at org.sonatype.nexus.repository.httpbridge.internal.ViewServlet.service(ViewServlet.java:126)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at com.google.inject.servlet.ServletDefinition.doServiceImpl(ServletDefinition.java:286)
at com.google.inject.servlet.ServletDefinition.doService(ServletDefinition.java:276)
at com.google.inject.servlet.ServletDefinition.service(ServletDefinition.java:181)
at com.google.inject.servlet.DynamicServletPipeline.service(DynamicServletPipeline.java:71)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:85)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:112)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
at org.sonatype.nexus.security.SecurityFilter.executeChain(SecurityFilter.java:85)
at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383)
at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
at org.sonatype.nexus.security.SecurityFilter.doFilterInternal(SecurityFilter.java:101)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
at org.sonatype.nexus.repository.httpbridge.internal.ExhaustRequestFilter.doFilter(ExhaustRequestFilter.java:80)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
at com.sonatype.nexus.licensing.internal.LicensingRedirectFilter.doFilter(LicensingRedirectFilter.java:108)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
at com.codahale.metrics.servlet.AbstractInstrumentedFilter.doFilter(AbstractInstrumentedFilter.java:97)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
at org.sonatype.nexus.internal.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:68)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
at org.sonatype.nexus.internal.web.EnvironmentFilter.doFilter(EnvironmentFilter.java:101)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
at org.sonatype.nexus.internal.web.HeaderPatternFilter.doFilter(HeaderPatternFilter.java:98)
at com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:82)
at com.google.inject.servlet.DynamicFilterPipeline.dispatch(DynamicFilterPipeline.java:104)
at com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:135)
at org.sonatype.nexus.bootstrap.osgi.DelegatingFilter.doFilter(DelegatingFilter.java:73)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1634)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1317)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1219)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at com.codahale.metrics.jetty9.InstrumentedHandler.handle(InstrumentedHandler.java:175)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:531)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102)
at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:762)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:680)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.sonatype.nexus.repository.storage.MissingBlobException: Blob default@55A6AFD5-295720F2-B6484746-7CB9D152-64D8B206:22602bf7-b65f-4254-9e74-88bec0560b6a exists in metadata, but is missing from the blobstore
at org.sonatype.nexus.repository.storage.StorageTxImpl.requireBlob(StorageTxImpl.java:938)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.sonatype.nexus.common.stateguard.SimpleMethodInvocation.proceed(SimpleMethodInvocation.java:53)
at org.sonatype.nexus.common.stateguard.MethodInvocationAction.run(MethodInvocationAction.java:39)
at org.sonatype.nexus.common.stateguard.StateGuard$GuardImpl.run(StateGuard.java:270)
at org.sonatype.nexus.common.stateguard.GuardedInterceptor.invoke(GuardedInterceptor.java:53)
at org.sonatype.nexus.common.stateguard.StateGuardAspect$1.invoke(StateGuardAspect.java:63)
at com.sun.proxy.$Proxy198.requireBlob(Unknown Source)
at org.sonatype.nexus.repository.maven.internal.MavenFacetImpl.get(MavenFacetImpl.java:183)
at org.sonatype.nexus.transaction.TransactionalWrapper.proceedWithTransaction(TransactionalWrapper.java:56)
… 106 common frames omitted
可以看到上面真正有用的错误就一句：
Caused by: org.sonatype.nexus.repository.storage.MissingBlobException: Blob default@55A6AFD5-295720F2-B6484746-7CB9D152-64D8B206:22602bf7-b65f-4254-9e74-88bec0560b6a exists in metadata, but is missing from the blobstore
网上查了半天发现相关的资料很少，最后可以确定是迁移引用的snapshot包的损坏，具体的解决方法一般都是说在bin目录下的配置文件nexus.vmoptions里指定正确的sonatype-work路径，但是我的路径是正确的。
看到有一篇文章说只能把损坏的删除再新建才行。好吧，现在只能这样了。但是现在有一个问题是我里面一个jar包都有几十个snapshot版本，而nexus管理界面里居然只能一个一个snapshot的删除，我醉了。。
由于一开始报错的只有 maven-metadata.xml 访问不了，于是我猜想是不是只把这个文件相关的删了，再上传就可以了？
实践得出结论，确实可行！只用把下面三个文件删除即可。这样就不用把之前的snapshot一个个手动删除了。。
- maven-metadata.xml
- maven-metadata.xml.md5
- maven-metadata.xml.sha1