unable to create new native thre

执行spark Streaming程序的时候，多个程序一起执行时，后面的程序就起不来，会报错：

java.lang.OutOfMemoryError: unable to create new native thread
        at java.lang.Thread.start0(Native Method)
        at java.lang.Thread.start(Thread.java:714)
        at io.netty.util.concurrent.SingleThreadEventExecutor.startThread(SingleThreadEventExecutor.java:720)
        at io.netty.util.concurrent.SingleThreadEventExecutor.execute(SingleThreadEventExecutor.java:689)
        at io.netty.channel.AbstractChannel$AbstractUnsafe.register(AbstractChannel.java:421)
        at io.netty.channel.SingleThreadEventLoop.register(SingleThreadEventLoop.java:60)
        at io.netty.channel.SingleThreadEventLoop.register(SingleThreadEventLoop.java:48)
        at io.netty.channel.MultithreadEventLoopGroup.register(MultithreadEventLoopGroup.java:64)
        at io.netty.bootstrap.ServerBootstrap$ServerBootstrapAcceptor.channelRead(ServerBootstrap.java:251)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:308)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:294)
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:846)
        at io.netty.channel.nio.AbstractNioMessageChannel$NioMessageUnsafe.read(AbstractNioMessageChannel.java:93)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
        at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
        at java.lang.Thread.run(Thread.java:745)

或者程序执行一段时间之后会报：

Driver stacktrace:
        at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1433)
        at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1421)
        at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1420)
        at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
        at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
        at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1420)
        at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:799)
        at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:799)
        at scala.Option.foreach(Option.scala:236)
        at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:799)
        at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1644)
        at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1603)
        at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1592)
        at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
        at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:620)
        at org.apache.spark.SparkContext.runJob(SparkContext.scala:1840)
        at org.apache.spark.SparkContext.runJob(SparkContext.scala:1853)
        at org.apache.spark.SparkContext.runJob(SparkContext.scala:1866)
        at org.apache.spark.SparkContext.runJob(SparkContext.scala:1937)
        at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1.apply(RDD.scala:920)
        at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1.apply(RDD.scala:918)
        at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:150)
        at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:111)
        at org.apache.spark.rdd.RDD.withScope(RDD.scala:316)
        at org.apache.spark.rdd.RDD.foreachPartition(RDD.scala:918)
        at com.neusoft.utils.db.KuduUtils$.insertRows(KuduUtils.scala:54)
        at com.neusoft.streaming.McStreamProcess$$anonfun$main$3.apply(McStreamProcess.scala:116)
        at com.neusoft.streaming.McStreamProcess$$anonfun$main$3.apply(McStreamProcess.scala:111)
        at org.apache.spark.streaming.dstream.DStream$$anonfun$foreachRDD$1$$anonfun$apply$mcV$sp$3.apply(DStream.scala:661)
        at org.apache.spark.streaming.dstream.DStream$$anonfun$foreachRDD$1$$anonfun$apply$mcV$sp$3.apply(DStream.scala:661)
        at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply$mcV$sp(ForEachDStream.scala:50)
        at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply(ForEachDStream.scala:50)
        at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply(ForEachDStream.scala:50)
        at org.apache.spark.streaming.dstream.DStream.createRDDWithLocalProperties(DStream.scala:426)
        at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply$mcV$sp(ForEachDStream.scala:49)
        at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply(ForEachDStream.scala:49)
        at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply(ForEachDStream.scala:49)
        at scala.util.Try$.apply(Try.scala:161)
        at org.apache.spark.streaming.scheduler.Job.run(Job.scala:39)
        at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply$mcV$sp(JobScheduler.scala:224)
       at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply(JobScheduler.scala:224)
        at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply(JobScheduler.scala:224)
        at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57)
        at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler.run(JobScheduler.scala:223)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.kududb.client.shaded.org.jboss.netty.channel.ChannelException: Failed to create a selector.
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.AbstractNioSelector.openSelector(AbstractNioSelector.java:343)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.AbstractNioSelector.<init>(AbstractNioSelector.java:100)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.AbstractNioWorker.<init>(AbstractNioWorker.java:52)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.NioWorker.<init>(NioWorker.java:45)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.NioWorkerPool.createWorker(NioWorkerPool.java:45)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.NioWorkerPool.createWorker(NioWorkerPool.java:28)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.AbstractNioWorkerPool.newWorker(AbstractNioWorkerPool.java:143)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.AbstractNioWorkerPool.init(AbstractNioWorkerPool.java:81)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.NioWorkerPool.<init>(NioWorkerPool.java:39)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.NioWorkerPool.<init>(NioWorkerPool.java:33)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory.<init>(NioClientSocketChannelFactory.java:151)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory.<init>(NioClientSocketChannelFactory.java:116)
        at org.kududb.client.AsyncKuduClient$AsyncKuduClientBuilder.createChannelFactory(AsyncKuduClient.java:2063)
        at org.kududb.client.AsyncKuduClient$AsyncKuduClientBuilder.access$000(AsyncKuduClient.java:1950)
        at org.kududb.client.AsyncKuduClient.<init>(AsyncKuduClient.java:231)
        at org.kududb.client.AsyncKuduClient.<init>(AsyncKuduClient.java:119)
        at org.kududb.client.AsyncKuduClient$AsyncKuduClientBuilder.build(AsyncKuduClient.java:2072)
        at org.kududb.client.KuduClient$KuduClientBuilder.build(KuduClient.java:320)
        at com.neusoft.utils.db.KuduUtils.<init>(KuduUtils.scala:29)
        at com.neusoft.utils.db.KuduUtils$$anonfun$insertRows$1.apply(KuduUtils.scala:56)
        at com.neusoft.utils.db.KuduUtils$$anonfun$insertRows$1.apply(KuduUtils.scala:54)
        at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1$$anonfun$apply$33.apply(RDD.scala:920)
        at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1$$anonfun$apply$33.apply(RDD.scala:920)
        at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1866)
        at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1866)
        at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
        at org.apache.spark.scheduler.Task.run(Task.scala:89)
        at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:242)
        ... 3 more
Caused by: java.io.IOException: 打开的文件过多
        at sun.nio.ch.IOUtil.makePipe(Native Method)
        at sun.nio.ch.EPollSelectorImpl.<init>(EPollSelectorImpl.java:65)
        at sun.nio.ch.EPollSelectorProvider.openSelector(EPollSelectorProvider.java:36)
        at java.nio.channels.Selector.open(Selector.java:227)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.SelectorUtil.open(SelectorUtil.java:63)
        at org.kududb.client.shaded.org.jboss.netty.channel.socket.nio.AbstractNioSelector.openSelector(AbstractNioSelector.java:341)

        ... 30 more

解决方法：
查看
/etc/security/limits.d/90-nproc.conf 文件，发下如下配置：

* soft nproc 1024
root soft nproc unlimited

即除了root用户之外，都有限制1024，注释掉该行即可。