Adding SocketChannel toString to connection exception messages

[Alan Bateman]

On 02/01/2018 21:25, Steven Schlansker wrote:
> :
> This would definitely be better than nothing!  But it's still difficult, for example a common allocation pattern for us would be to assign networks to availability zones:
>
> 10.0.1.0/24 10.0.2.0/24 10.0.3.0/24
>
> then if you pick the same last number for a well known service, you might end up with instances at 10.0.1.2, 10.0.2.2, 10.0.3.2 -- so depending on which octets are obscured you may end up with no useful information.
>
> The triggering incident for us was that one of our Amazon ELBs started responding incorrectly (blackholing data) --
> so when you resolve "my-elb-1.amazonaws.amazon.com" you'd get three different IP addresses, and depending on which one
> is picked for the connect operation, you'll get all data blackholed.
Socket/SocketChannel connect take a single address, not a hostname that 
is potentially mapped to multiple addresses. Maybe you mean the Socket 
constructors that takes a hostname and do the lookup before attempt to 
establish a connection?

In any case, if the exception message includes the address/port details 
then it shouldn't matter which constructors are used. Also note that 
when you look at the non-blocking cases then you'll see the exception is 
thrown by finishConnect, not connect. This is nothing reason to handle 
this completely in java and avoid changes to the native code.

-Alan