java.util.concurrent.FutureTask.run(FutureTask.java:266) at hudson.remoting.AtmostOneThreadExecutor$Worker.run(AtmostOneThreadExecutor.java:110) at java.lang.Thread.run(Thread.java:745)
Durable Task Plugin	
 Failure -
hudson.util.IOException2: Failed to download from http://updates.jenkins-ci.org/download/plugins/durable-task/1.9/durable-task.hpi (redirected to: http://mirrors.jenkins-ci.org/plugins/durable-task/1.9/durable-task.hpi)
	at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1056)
	at hudson.model.UpdateCenter$DownloadJob._run(UpdateCenter.java:1478)
	at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:1659)
	at hudson.model.UpdateCenter$DownloadJob.run(UpdateCenter.java:1456)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at hudson.remoting.AtmostOneThreadExecutor$Worker.run(AtmostOneThreadExecutor.java:110)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: Server returned HTTP response code: 504 for URL: http://mirrors.jenkins-ci.org/plugins/durable-task/1.9/durable-task.hpi
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1890)
	at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1885)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.net.www.protocol.http.HttpURLConnection.getChainedException(HttpURLConnection.java:1884)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1457)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441)
	at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1008)
	... 7 more
Caused by: java.io.IOException: Server returned HTTP response code: 504 for URL: http://mirrors.jenkins-ci.org/plugins/durable-task/1.9/durable-task.hpi
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1840)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441)
	at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:2943)
	at java.net.URLConnection.getHeaderFieldLong(URLConnection.java:629)
	at java.net.URLConnection.getContentLengthLong(URLConnection.java:501)
	at java.net.URLConnection.getContentLength(URLConnection.java:485)
	at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:1007)