[Twisted-Python] Instrumenting Reactors

[Phil Mayers]

On 06/04/11 13:19, Itamar Turner-Trauring wrote:
> On Wed, 2011-04-06 at 10:55 +0100, Paul Thomas wrote:
>> I have a reactor which is getting busier over time and I'd like to
>> find out where the cycles are going. Using the profiler isn't really
>> practical on a server running for days, so I'd like to instrument the
>> reactor to show me which I/O events are taking the longest to deal
>> with.
>
> You may just want to wrap manual profiling code around your code's entry
> points (e.g. dataReceived/connectionMade/connectionLost/whatever gets
> callLatered). It would be nice if you could get the reactor to turn this
> sort of info on/off in a running system, though.

I've done this with a decorator & dictionary before, including counting 
time inside deferred return values separately from the original function 
call.