Socket.IO is now completely instrumented by a minimalistic yet tremendously powerful utility called debug by TJ Holowaychuk.
Before 1.0, the Socket.IO server would default to logging everything out to the console. This turned out to be annoyingly verbose for many users (although extremely useful for others), so now we default to being completely silent by default.
The basic idea is that each module used by Socket.IO provides different debugging scopes that give you insight into the internals. B