logging.SocketHandler connections

Vinay Sajip vinay_sajip at yahoo.co.uk
Mon Nov 19 18:30:03 CET 2007


On Nov 19, 10:27 am, oj <ojee... at gmail.com> wrote:
> On Nov 16, 2:31 pm, Vinay Sajip <vinay_sa... at yahoo.co.uk> wrote:
>
> Here is the server code. Pretty much directly copied from the example,
> aside from not having the the handler loop forever, and queing the
> records instead of dealing with the directly.
>
> After further investigation, running the client with a long timeout,
> without the server, so that every connection will fail, produces
> results much closer to what I would expect. Connections attempted for
> each message initially, but not for all of the later messages as the
> retry time increases.
>
> The point is kinda moot now, since I guess not closing the connection
> is the 'right way' to do this, but I'm still interested in why I see
> this behaviour when the server closes the connection.
>

I've investigated this and the issue appears not to be related to
closing connections. Your server code differs from the example in the
docs in one crucial way: there is a while loop which you have left out
in the handle() function, which deals with multiple logging events
received in one packet. Add this back in, and all 9 events are
received.

    def handle(self):
        while 1:
            chunk = self.connection.recv(4)

            if len(chunk) < 4:
                break

            slen = struct.unpack(">L", chunk)[0]
            chunk = self.connection.recv(slen)

            while len(chunk) < slen:
                chunk = chunk + self.connection.recv(slen -
len(chunk))

            obj = self.unPickle(chunk)
            record = logging.makeLogRecord(obj)
            queue_lock.acquire()
            queue.insert(0, record)
            queue_lock.release()

So it appears that due to buffering, 3 socket events are sent in each
packet sent over the wire. You were only processing the first of each
set of three, viz. nos. 0, 3, 6 and 9. Mystery solved, it appears!

Regards,


Vinay Sajip



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