When a network element disconnects the channel we end up with a rather alerting and verbose message:
2021-08-14T04:19:36,397 | WARN | globalWorkerGroup-3-9 | NetconfDeviceCommunicator | 277 - org.opendaylight.netconf.sal-netconf-connector - 2.0.2 | RemoteDevice{scale-device-8469}: Session went down java.io.IOException: End of input detected. Close the session. at org.opendaylight.netconf.nettyutil.AbstractNetconfSession.endOfInput(AbstractNetconfSession.java:94) [bundleFile:?] at org.opendaylight.netconf.nettyutil.AbstractNetconfSession.channelInactive(AbstractNetconfSession.java:174) [bundleFile:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:262) [bundleFile:4.1.65.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:248) [bundleFile:4.1.65.Final] at io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:241) [bundleFile:4.1.65.Final] at io.netty.handler.codec.ByteToMessageDecoder.channelInputClosed(ByteToMessageDecoder.java:389) [bundleFile:4.1.65.Final] at io.netty.handler.codec.ByteToMessageDecoder.channelInactive(ByteToMessageDecoder.java:354) [bundleFile:4.1.65.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:262) [bundleFile:4.1.65.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:248) [bundleFile:4.1.65.Final] at io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:241) [bundleFile:4.1.65.Final] at io.netty.handler.codec.ByteToMessageDecoder.channelInputClosed(ByteToMessageDecoder.java:389) [bundleFile:4.1.65.Final] at io.netty.handler.codec.ByteToMessageDecoder.channelInactive(ByteToMessageDecoder.java:354) [bundleFile:4.1.65.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:262) [bundleFile:4.1.65.Final] at io.netty.channel.AbstractChannelHandlerContext.access$300(AbstractChannelHandlerContext.java:61) [bundleFile:4.1.65.Final] at io.netty.channel.AbstractChannelHandlerContext$4.run(AbstractChannelHandlerContext.java:253) [bundleFile:4.1.65.Final] at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164) [bundleFile:4.1.65.Final] at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472) [bundleFile:4.1.65.Final] at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:500) [bundleFile:4.1.65.Final] at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989) [bundleFile:4.1.65.Final] at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) [bundleFile:4.1.65.Final] at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [bundleFile:4.1.65.Final] at java.lang.Thread.run(Thread.java:829) [?:?]
In a large-scale network we can expect these to happen quite regularly, hence the current level of detail is too much and a warning is not quite appropriate.