error log

[2017-10-31T09:16:22,432][ERROR][o.e.t.n.Netty4Utils      ] fatal error on the network layer
  at org.elasticsearch.transport.netty4.Netty4Utils.maybeDie(Netty4Utils.java:179)
  at org.elasticsearch.transport.netty4.Netty4MessageChannelHandler.exceptionCaught(Netty4MessageChannelHandler.java:83)
  at io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:285)
  at io.netty.channel.AbstractChannelHandlerContext.notifyHandlerException(AbstractChannelHandlerContext.java:850)
  at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:364)
  at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
  at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
  at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310)
  at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:297)
  at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:413)
  at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
  at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
  at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
  at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
  at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334)
  at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
  at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
  at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926)
  at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:134)
  at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:644)
  at io.netty.channel.nio.NioEventLoop.processSelectedKeysPlain(NioEventLoop.java:544)
  at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:498)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:458)
  at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
  at java.lang.Thread.run(Thread.java:745)
[2017-10-31T09:16:22,434][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [ubuntu-100] fatal error in thread [Thread-5], exiting
java.lang.StackOverflowError: null
  at java.util.Collections$UnmodifiableCollection.size(Collections.java:1030) ~[?:1.8.0_45]
  at java.util.Collections$UnmodifiableCollection.size(Collections.java:1030) ~[?:1.8.0_45]
  at org.elasticsearch.cluster.routing.PlainShardsIterator.remaining(PlainShardsIterator.java:50) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.successfulShardExecution(InitialSearchPhase.java:196) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.skipShard(InitialSearchPhase.java:323) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.AbstractSearchAsyncAction.skipShard(AbstractSearchAsyncAction.java:321) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.maybeExecuteNext(InitialSearchPhase.java:147) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.successfulShardExecution(InitialSearchPhase.java:207) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.skipShard(InitialSearchPhase.java:323) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.AbstractSearchAsyncAction.skipShard(AbstractSearchAsyncAction.java:321) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.maybeExecuteNext(InitialSearchPhase.java:147) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.successfulShardExecution(InitialSearchPhase.java:207) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.skipShard(InitialSearchPhase.java:323) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.AbstractSearchAsyncAction.skipShard(AbstractSearchAsyncAction.java:321) ~[elasticsearch-5.6.1.jar:5.6.1]
  at org.elasticsearch.action.search.InitialSearchPhase.maybeExecuteNext(InitialSearchPhase.java:147) ~[elasticsearch-5.6.1.jar:5.6.1]
  ...