查询报错，节点失活，大量节点掉

如下是服务端的日志：
[2017-12-11 17:09:42,834][DEBUG][action.search            ] [node-1] [xxx][28], node[xxxx], [P], v[3], s[STARTED], a[id=xxxxx]: Failed to execute [org.elasticsearch.action.search.SearchRequest@4020fc23] lastShard [true]
RemoteTransportException[[node-1][xxxxx][indices:data/read/search[phase/query+fetch]]]; nested: EsRejectedExecutionException[rejected execution of org.elasticsearch.transport.netty.MessageChannelHandler$RequestHandler@42b9985a on EsThreadPoolExecutor[search, queue capacity = 1000, org.elasticsearch.common.util.concurrent.EsThreadPoolExecutor@7caa4cf9[Running, pool size = 49, active threads = 49, queued tasks = 1000, completed tasks = 4668605]]];
Caused by: EsRejectedExecutionException[rejected execution of org.elasticsearch.transport.netty.MessageChannelHandler$RequestHandler@42b9985a on EsThreadPoolExecutor[search, queue capacity = 1000, org.elasticsearch.common.util.concurrent.EsThreadPoolExecutor@7caa4cf9[Running, pool size = 49, active threads = 49, queued tasks = 1000, completed tasks = 4668605]]]
    at org.elasticsearch.common.util.concurrent.EsAbortPolicy.rejectedExecution(EsAbortPolicy.java:50)
    at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:823)
    at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1369)
    at org.elasticsearch.common.util.concurrent.EsThreadPoolExecutor.execute(EsThreadPoolExecutor.java:85)
    at org.elasticsearch.transport.netty.MessageChannelHandler.handleRequest(MessageChannelHandler.java:247)
    at org.elasticsearch.transport.netty.MessageChannelHandler.messageReceived(MessageChannelHandler.java:114)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:296)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.unfoldAndFireMessageReceived(FrameDecoder.java:462)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.callDecode(FrameDecoder.java:443)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.messageReceived(FrameDecoder.java:303)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791)
    at org.elasticsearch.common.netty.OpenChannelsHandler.handleUpstream(OpenChannelsHandler.java:75)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:559)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:268)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:255)
    at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:88)
    at org.jboss.netty.channel.socket.nio.AbstractNioWorker.process(AbstractNioWorker.java:108)
    at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:337)
    at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:89)
    at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:178)
    at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108)
    at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
 
 
是否是高并发引起的，查看了下查询数据量也不大，查询次数较多，哪里可以调整的，大神来看看。