[Twisted-Python] Catching error in protocol.ReconnectingClientFactory

[Adrian Overbury]

On 25/06/2012, at 10:16 PM, Martin <martin at webscio.net> wrote:

> On 14/06/12 12:38, Martin wrote:
>> Hi, thanks for your reply.
>> 
>> Indeed, the ReconnectingClientFactory is being sent the Failure object to
>> 
>> def clientConnectionLost(self, connector, reason):
>>        log.msg('Lost connection. Reason: %s' % reason)
>> protocol.ReconnectingClientFactory.clientConnectionLost(self, 
>> connector, reason)
>> 
>> where "reason" is the Failure object that is "unhandled". is there 
>> anything I could do to it there to make it handled?
>> 
>> Also, the documentation in 
>> http://twistedmatrix.com/documents/current/core/howto/defer.html says 
>> that one can do d.addErrback(err.log) to deal with unhandled errors, 
>> but what is d?
>> 
>> In general, I'm not doing anything special.. I'm creating a 
>> ReconnectingClientFactory and connecting it to a server..
>> f = MyReconnectingClientFactory(..)
>> reactor.connectSSL(url, port, f, ssl.ClientContextFactory())
>> reactor.run()
>> 
>> Basically it. Any thoughts? Thanks a lot!
>>> On Jun 11, 2012, at 8:01 AM, Martin wrote:
>>> 
>>>> Hi there,
>>>> 
>>>> I've been looking around for a solution for several hours now, and 
>>>> maybe
>>>> I'm just missing something..
>>>> 
>>>> I've a factory that implements protocol.ReconnectingClientFactory which
>>>> works just fine, however, whenever the program ends running, I get a
>>>> bunch of Unhandled error in Deferred messages in my log for each
>>>> disconnection that occurred during runtime, such as Failure:
>>>> twisted.internet.error.ConnectionLost: ...
>>>> 
>>>> Is there any way I could somehow "handle" these during runtime, so that
>>>> my log wouldn't be spammed with this at the end.. (or avoid it being
>>>> spammed somehow..)
>>> These messages are coming from some code which is issuing Deferreds, 
>>> not from ReconnectingClientFactory.  You need to add an errback to 
>>> those Deferreds in your application code.  There's no way to write a 
>>> catch-all, just like there's no way to write a catch-all that can 
>>> stop exceptions from being raised in basic Python.
>>> 
>>> I can't say more without a code example, preferably 
>>> a<http://sscce.org/>.
>>> 
>>> -glyph
>>> 
>>> 
>>> _______________________________________________
>>> Twisted-Python mailing list
>>> Twisted-Python at twistedmatrix.com
>>> http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
>>> 
>>> 
>> 
> No suggestions as to how I could get rid of this? :(
> 
> 

I believe glyph gave you the answer to that already.  In your example above of d.addErrBack, d is the deferred object.  Each of those needs to have an errback handler attached to it.  If you don't want to see anything out of them, simply don't print anything.

> _______________________________________________
> Twisted-Python mailing list
> Twisted-Python at twistedmatrix.com
> http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python