运行selenium RemoteWebdriver时jenkins机器中的InvocationTargetException

Question

我做了一个设置来在jenkins构建期间运行selenium脚本。 Jenkins在linux机器上可用，而selenium-server-standalone-2.39.0.jar在jenkins机器上运行。

selenium网格将在windows机器中运行脚本，代码如下，

Jun 24, 2015 4:15:57 AM hudson.node_monitors.ResponseTimeMonitor$1 monitor
WARNING: Making NewSlave offline because it’s not responding
Jun 24, 2015 4:44:04 AM hudson.ExpressionFactory2$JexlExpression evaluate
WARNING: Caught exception evaluating: it.transientActions in /job/Selenium_GRID/4/console. Reason: java.lang.reflect.InvocationTargetException
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    .....
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
    at com.chikli.hudson.plugin.naginator.NaginatorActionFactory.createFor(NaginatorActionFactory.java:20)
    at hudson.model.Run.getTransientActions(Run.java:362)
    ... 122 more
Jun 24, 2015 5:15:42 AM hudson.model.Run execute

我在jenkins中也有以下设置，

maven用于运行selenium测试套件并发布junit测试报告。

有时jenkins机器会出现以下错误，

Jun 22, 2015 6:46:04 PM org.openqa.grid.selenium.proxy.DefaultRemoteProxy isAlive
WARNING: Failed to check status of node: Connection refused
Jun 22, 2015 6:47:12 PM org.openqa.grid.selenium.proxy.DefaultRemoteProxy isAlive
WARNING: Failed to check status of node: Connection timed out
Jun 22, 2015 6:47:12 PM org.openqa.grid.selenium.proxy.DefaultRemoteProxy onEvent
WARNING: Marking the node as down. Cannot reach the node for 2 tries.
Jun 22, 2015 6:48:20 PM org.openqa.grid.selenium.proxy.DefaultRemoteProxy isAlive
WARNING: Failed to check status of node: Connection refused
Jun 22, 2015 6:48:20 PM org.openqa.grid.selenium.proxy.DefaultRemoteProxy onEvent
WARNING: Unregistering the node. It's been down for 67828 milliseconds.
Jun 22, 2015 6:48:20 PM org.openqa.grid.internal.Registry removeIfPresent
WARNING: Proxy 'host :http://xxx.xxx.y.z:5555' was previously registered.  Cleaning up any stale test sessions.

这是selenium服务器日志，

public class Parent {
    void display() {
        // some code
    }
}

问题在于，当硒脚本失败或有时在jenkins测试报告中查看失败的测试结果时，jenkins会崩溃。任何人都可以建议为什么会出现这个问题以及如何解决这个问题？  由于在jenkins机器上运行的selenium服务器或任何其他原因，是否会出现此问题？