Jenkins node connection troubles

Question

Hi i have got the following error but my node is up and in jenkins logs everything is ok but on some of my jobs which are going on the nodes i've got the following trouble

12:59:29 [EnvInject] - Loading node environment variables. 12:59:29 ERROR: SEVERE ERROR occurs 12:59:29 org.jenkinsci.lib.envinject.EnvInjectException: hudson.remoting.ChannelClosedException: channel is    already closed 12:59:29    at org.jenkinsci.plugins.envinject.service.EnvironmentVariablesNodeLoader.gatherEnvironmentVariablesNode(EnvironmentVariablesNodeLoader.java:75) 12:59:29    at org.jenkinsci.plugins.envinject.EnvInjectListener.loadEnvironmentVariablesNode(EnvInjectListener.java:81) 12:59:29    at org.jenkinsci.plugins.envinject.EnvInjectListener.setUpEnvironment(EnvInjectListener.java:39) 12:59:29    at hudson.model.AbstractBuild$AbstractBuildExecution.createLauncher(AbstractBuild.java:637) 12:59:29    at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:543) 12:59:29    at hudson.model.Run.execute(Run.java:1676) 12:59:29    at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43) 12:59:29    at hudson.model.ResourceController.execute(ResourceController.java:88) 12:59:29    at hudson.model.Executor.run(Executor.java:231) 12:59:29 Caused by: hudson.remoting.ChannelClosedException: channel is already closed 12:59:29    at hudson.remoting.Channel.send(Channel.java:524) 12:59:29    at hudson.remoting.Request.call(Request.java:129) 12:59:29    at hudson.remoting.Channel.call(Channel.java:722) 12:59:29    at hudson.FilePath.act(FilePath.java:1003) 12:59:29    at org.jenkinsci.plugins.envinject.service.EnvironmentVariablesNodeLoader.gatherEnvironmentVariablesNode(EnvironmentVariablesNodeLoader.java:44)  12:59:29   ... 8 more 12:59:29 Caused by: java.io.IOException 12:59:29    at hudson.remoting.Channel.close(Channel.java:1007) 12:59:29    at hudson.slaves.ChannelPinger$1.onDead(ChannelPinger.java:110) 12:59:29    at hudson.remoting.PingThread.ping(PingThread.java:120) 12:59:29    at hudson.remoting.PingThread.run(PingThread.java:81) 12:59:29 Caused by: java.util.concurrent.TimeoutException: Ping started on 1401694124050 hasn't completed at 1401694364050 12:59:29    ... 2 more 12:59:29 Archiving artifacts 12:59:29 Email was triggered for: Failure 12:59:29 Sending email for trigger: Failure 12:59:29 ERROR: Error: No workspace found! 12:59:29 Error retrieving environment vars: channel is already closed 12:59:29 Sending email to: $EMAIL_USERS 12:59:49 Error sending to the following INVALID addresses: $EMAIL_USERS 12:59:49 [EnvInject] - [ERROR] - SEVERE ERROR occurs: channel is already closed   12:59:49 Finished: FAILURE 

Answer 1

I don't know the reason but it happens after a restart of the slave machine or when the machine lost the connection (during a long period).

The problem (in my case) was that the process java -jar slave.jar was not running in the slave. For solve it, try to reconnect the node in Jenkins menus, so go to:

Manage Jenkins -> Manage Nodes -> YOUR_NODE -> Disconnect

Manage Jenkins -> Manage Nodes -> YOUR_NODE -> Launch slave agent