There is no sense to run profiler in instrumentation mode on a high load.
Instead of using instrumentation you should use sampling mode.
I have had spent some time recently making netty 3.6 sending some message when connection has been established.
What documentation suggests to do is to extend
SimpleChannelUpstreamHandler and override method
It works fine unless
SslHandler is used in the pipeline.
If handler is present,
channelConnected() was never called on my handler.