at org.elasticsearch.client.transport.TransportClientNodesService.ensureNodesAreAvailable(TransportClientNodesService.java:326)
at org.elasticsearch.client.transport.TransportClientNodesService.execute(TransportClientNodesService.java:223)
at org.elasticsearch.client.transport.support.TransportProxyClient.execute(TransportProxyClient.java:55)
at org.elasticsearch.client.transport.TransportClient.doExecute(TransportClient.java:295)
at org.elasticsearch.client.support.AbstractClient.execute(AbstractClient.java:359)
at org.elasticsearch.action.ActionRequestBuilder.execute(ActionRequestBuilder.java:86)
at org.elasticsearch.action.ActionRequestBuilder.execute(ActionRequestBuilder.java:56)
at com.verysu.es.ESUtil.search(ESUtil.java:132)
at com.verysu.test.es.ESUtilTest.testSearch(ESUtilTest.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

情况①：

使用elasticsearch测试添加index文档的时候出现如上异常。那是因为集群名词cluster.name这个用错了。配置文件默认的是elasticsearch，然后我代码里使用的是另一个名称，只要把配置文件和代码指定的集群名称一致就OK。 

情况②：

我遇到的第二个比较坑的问题，就是在用客户端测试的时候，没有将每次测试完之后把client给close掉：client.close()。因为这样之后，不管重启还是怎么弄，基本上都会出现Node不可用，用netstat -ano命令查看，发现很多占用着9300端口，并且是time_wait状态，所以就知道了是连接没释放，没有可用资源，把9300的服务都搞瘫了。

可能还有其它原因，这里只是我遇到的一些，若还有，请告知，我记录^_^