logstash5.6.13启动后一直刷WARN日志

logstash5.6.13启动后一直刷WARN日志，输出到kafka。日志最终可以到达ES，请问什么原因
 

日志如下：
[2018-12-03T18:14:32,342][INFO ][org.logstash.beats.BeatsHandler] Exception: org.logstash.beats.BeatsParser$InvalidFrameProtocolException: Invalid Frame Type, received: 69, from: /10.206.64.149:18376
[2018-12-03T18:14:32,342][WARN ][io.netty.channel.DefaultChannelPipeline] An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
io.netty.handler.codec.DecoderException: org.logstash.beats.BeatsParser$InvalidFrameProtocolException: Invalid Frame Type, received: 69
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:442) ~[netty-all-4.1.3.Final.jar:4.1.3.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:248) ~[netty-all-4.1.3.Final.jar:4.1.3.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:372) ~[netty-all-4.1.3.Final.jar:4.1.3.Final]
at io.netty.channel.AbstractChannelHandlerContext.access$600(AbstractChannelHandlerContext.java:38) ~[netty-all-4.1.3.Final.jar:4.1.3.Final]
at io.netty.channel.AbstractChannelHandlerContext$7.run(AbstractChannelHandlerContext.java:363) ~[netty-all-4.1.3.Final.jar:4.1.3.Final]
at io.netty.util.concurrent.DefaultEventExecutor.run(DefaultEventExecutor.java:66) ~[netty-all-4.1.3.Final.jar:4.1.3.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:877) [netty-all-4.1.3.Final.jar:4.1.3.Final]
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144) [netty-all-4.1.3.Final.jar:4.1.3.Final]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_181]
Caused by: org.logstash.beats.BeatsParser$InvalidFrameProtocolException: Invalid Frame Type, received: 69
at org.logstash.beats.BeatsParser.decode(BeatsParser.java:92) ~[logstash-input-beats-3.1.32.jar:?]
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:411) ~[netty-all-4.1.3.Final.jar:4.1.3.Final]
... 8 more