elasticsearch shutdown

elasticsearch logs

[2016-08-05 09:42:23,093][INFO ][node                     ] [logstash1004] stopping ...
[2016-08-05 09:42:23,253][DEBUG][action.admin.indices.forcemerge] [logstash1004] failed to execute [indices:admin/opti
mize] on node [Y0LDbu-9Qluz9H7z6IapSg]
TransportException[transport stopped, action: indices:admin/optimize[n]]
        at org.elasticsearch.transport.TransportService$2.run(TransportService.java:206)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
[2016-08-05 09:42:23,253][DEBUG][action.admin.indices.forcemerge] [logstash1004] failed to execute [indices:admin/opti
mize] on node [lYF1WLrRRgmRjTGUViqzZA]
TransportException[transport stopped, action: indices:admin/optimize[n]]
        at org.elasticsearch.transport.TransportService$2.run(TransportService.java:206)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
[2016-08-05 09:42:23,267][DEBUG][action.admin.indices.forcemerge] [logstash1004] failed to execute [indices:admin/opti
mize] on node [4UXNV6w_TPySDt73KkT-mQ]
TransportException[transport stopped, action: indices:admin/optimize[n]]
        at org.elasticsearch.transport.TransportService$2.run(TransportService.java:206)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
[2016-08-05 09:42:23,294][WARN ][netty.channel.DefaultChannelPipeline] An exception was thrown by an exception handler
.
java.util.concurrent.RejectedExecutionException: Worker has already been shutdown
        at org.jboss.netty.channel.socket.nio.AbstractNioSelector.registerTask(AbstractNioSelector.java:120)
        at org.jboss.netty.channel.socket.nio.AbstractNioWorker.executeInIoThread(AbstractNioWorker.java:72)
        at org.jboss.netty.channel.socket.nio.NioWorker.executeInIoThread(NioWorker.java:36)
        at org.jboss.netty.channel.socket.nio.AbstractNioWorker.executeInIoThread(AbstractNioWorker.java:56)
        at org.jboss.netty.channel.socket.nio.NioWorker.executeInIoThread(NioWorker.java:36)
        at org.jboss.netty.channel.socket.nio.AbstractNioChannelSink.execute(AbstractNioChannelSink.java:34)
        at org.jboss.netty.channel.DefaultChannelPipeline.execute(DefaultChannelPipeline.java:636)
        at org.jboss.netty.channel.Channels.fireExceptionCaughtLater(Channels.java:496)
        at org.jboss.netty.channel.AbstractChannelSink.exceptionCaught(AbstractChannelSink.java:46)
        at org.jboss.netty.channel.DefaultChannelPipeline.notifyHandlerException(DefaultChannelPipeline.java:658)
        at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendDownstream(DefaultChannelPi
peline.java:781)
        at org.jboss.netty.channel.Channels.write(Channels.java:725)
        at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.doEncode(OneToOneEncoder.java:71)
        at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.handleDownstream(OneToOneEncoder.java:59)
        at org.jboss.netty.channel.DefaultChannelPipeline.sendDownstream(DefaultChannelPipeline.java:591)
        at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendDownstream(DefaultChannelPipeline.java:784)
        at org.elasticsearch.http.netty.pipelining.HttpPipeliningHandler.handleDownstream(HttpPipeliningHandler.java:87)
        at org.jboss.netty.channel.DefaultChannelPipeline.sendDownstream(DefaultChannelPipeline.java:591)
        at org.jboss.netty.channel.DefaultChannelPipeline.sendDownstream(DefaultChannelPipeline.java:582)
        at org.elasticsearch.http.netty.NettyHttpChannel.sendResponse(NettyHttpChannel.java:146)
        at org.elasticsearch.rest.action.support.RestResponseListener.processResponse(RestResponseListener.java:43)
        at org.elasticsearch.rest.action.support.RestActionListener.onResponse(RestActionListener.java:49)
        at org.elasticsearch.action.support.TransportAction$1.onResponse(TransportAction.java:89)
        at org.elasticsearch.action.support.TransportAction$1.onResponse(TransportAction.java:85)
        at org.elasticsearch.action.support.broadcast.node.TransportBroadcastByNodeAction$AsyncAction.onCompletion(TransportBroadcastByNodeAction.java:378)
        at org.elasticsearch.action.support.broadcast.node.TransportBroadcastByNodeAction$AsyncAction.onNodeFailure(TransportBroadcastByNodeAction.java:363)
        at org.elasticsearch.action.support.broadcast.node.TransportBroadcastByNodeAction$AsyncAction$1.handleException(TransportBroadcastByNodeAction.java:324)
        at org.elasticsearch.transport.TransportService$2.run(TransportService.java:206)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)