Description
A Transport$Connection comprises several TCP channels. When establishing such a connection we first open all the TCP channels. If this process takes longer than the timeout (default 30s) then we tear down any successful channels and report a failure. Today the failure message is just "connect_timeout[" + connectionProfile.getConnectTimeout() + "]" indicating the timeout that elapsed, but it would also be useful to know whether we failed to connect any channels within the time, or whether perhaps it was just one that failed: if some succeed then that suggests an application issue whereas if none succeed then it's more likely infrastructural.
Let's extend this message to report the number of channels which didn't connect within the timeout, and maybe even describe the channels which did connect successfully (if any).