启动jenkins解锁后，报错“Failed to update the default Update Site 'default'”
报错信息：
// 报错信息
2019-11-05 02:01:43.970+0000 [id=40] INFO hudson.util.Retrier#start: The attempt #1 to do the action check updates server failed with an allowed exception:
java.net.SocketTimeoutException: connect timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:668)
at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)
at sun.net.www.protocol.https.HttpsClient.(HttpsClient.java:264)
at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1105)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:999)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)
at sun.net.www.protocol.http.HttpURLConnection.followRedirect0(HttpURLConnection.java:2662)
at sun.net.www.protocol.http.HttpURLConnection.followRedirect(HttpURLConnection.java:2584)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1770)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
at hudson.model.DownloadService.loadJSON(DownloadService.java:167)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:189)
at hudson.PluginManager.checkUpdatesServer(PluginManager.java:1762)
at hudson.util.Retrier.start(Retrier.java:62)
at hudson.PluginManager.doCheckUpdatesServer(PluginManager.java:1733)
at jenkins.model.DownloadSettings$DailyCheck.execute(DownloadSettings.java:130)
at hudson.model.AsyncPeriodicWork$1.run(AsyncPeriodicWork.java:101)
at java.lang.Thread.run(Thread.java:745)
2019-11-05 02:01:43.971+0000 [id=40] INFO hudson.util.Retrier#start: Calling the listener of the allowed exception 'connect timed out' at the attempt #1 to do the action check updates server
2019-11-05 02:01:43.977+0000 [id=40] INFO hudson.util.Retrier#start: Attempted the action check updates server for 1 time(s) with no success
2019-11-05 02:01:43.985+0000 [id=27] WARNING hudson.model.UpdateCenter#updateDefaultSite: Upgrading Jenkins. Failed to update the default Update Site 'default'. Plugin upgrades may fail.
java.net.SocketTimeoutException: connect timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:668)
at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)
at sun.net.www.protocol.https.HttpsClient.(HttpsClient.java:264)
at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1105)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:999)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)
at sun.net.www.protocol.http.HttpURLConnection.followRedirect0(HttpURLConnection.java:2662)
at sun.net.www.protocol.http.HttpURLConnection.followRedirect(HttpURLConnection.java:2584)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1770)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
at hudson.model.DownloadService.loadJSON(DownloadService.java:167)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:189)
at hudson.model.UpdateCenter.updateDefaultSite(UpdateCenter.java:2456)
at jenkins.install.SetupWizard.init(SetupWizard.java:168)
at jenkins.install.InstallState$InitialSecuritySetup.initializeState(InstallState.java:166)
at jenkins.model.Jenkins.setInstallState(Jenkins.java:1089)
at jenkins.install.InstallUtil.proceedToNextStateFrom(InstallUtil.java:96)
at jenkins.install.InstallState$Unknown.initializeState(InstallState.java:84)
at jenkins.model.Jenkins$16.run(Jenkins.java:3277)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:296)
at jenkins.model.Jenkins$5.runTask(Jenkins.java:1118)
at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:214)
at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:117)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
2019-11-05 02:01:44.018+0000 [id=40] SEVERE hudson.PluginManager#doCheckUpdatesServer: Error checking update sites for 1 attempt(s). Last exception was: SocketTimeoutException: connect timed out
2019-11-05 02:01:44.058+0000 [id=40] INFO hudson.model.AsyncPeriodicWork$1#run: Finished Download metadata. 36,249 ms
2019-11-05 02:01:44.078+0000 [id=27] INFO jenkins.InitReactorRunner$1#onAttained: Completed initialization
看到最后报错是因为
2019-11-05 02:01:43.985+0000 [id=27] WARNING hudson.model.UpdateCenter#updateDefaultSite: Upgrading Jenkins. Failed to update the default Update Site 'default'. Plugin upgrades may fail.
java.net.SocketTimeoutException: connect timed out
找到相关的配置文件
[root@auto-server02 jenkins]# cat /var/lib/jenkins/hudson.model.UpdateCenter.xml
default
https://updates.jenkins.io/update-center.json
考虑是url问题，修改为国内的源，也有朋友说是https的问题， 建议改为http，经过验证， 不是这个的原因，还是要修改源，如下：
[root@auto-server02 jenkins]# vi /var/lib/jenkins/hudson.model.UpdateCenter.xml
default
https://mirrors.tuna.tsinghua.edu.cn/jenkins/updates/update-center.json
重启Jenkins
systemctl restart jenkins
此时再去登录jenkins，插件可以正确显示 ， 报错不在存在，问题解决。