Network glitches costing 15 minutes a pop

[Mark Hammond]

Fairly regularly, I notice pulling a small number of updates from launchpad
can take a very long time - 30 minutes isn't uncommon.  Looking in the logs,
I see:

...
34.219  http readv of b9079703ef4bc0a8975cfc8809aa122e.pack  offsets => 3
collapsed 2
34.946  http readv of 5a4f2c46b38ea8f69400e7216da83b89.tix  offsets => 2
collapsed 2
937.223  got pycurl error: 18, transfer closed with 65726 bytes remaining to
read, (18, 'transfer closed with 65726 bytes remaining to read'), url:
http://bazaar.launchpad.net/%7Ebzr/bzr/bzr.1.6/.bzr/repository/indices/5a4f2
c46b38ea8f69400e7216da83b89.tix 
937.223  Exception ShortReadvError(): readv() read unknown bytes rather than
unknown bytes at unknown for
"http://bazaar.launchpad.net/%7Ebzr/bzr/bzr.1.6/.bzr/repository/indices/5a4f
2c46b38ea8f69400e7216da83b89.tix": Server aborted the request during
http._readv
937.223  http readv of 5a4f2c46b38ea8f69400e7216da83b89.tix  offsets => 2
collapsed 2
... <going again at a good pace>
960.089  http readv of 5a4f2c46b38ea8f69400e7216da83b89.six  offsets => 2
collapsed 2
1860.905  got pycurl error: 18, transfer closed with 65723 bytes remaining
to read, (18, 'transfer closed with 65723 bytes remaining to read'), url:
http://bazaar.launchpad.net/%7Ebzr/bzr/bzr.1.6/.bzr/repository/indices/5a4f2
c46b38ea8f69400e7216da83b89.six
1860.905  Exception ShortReadvError(): readv() read unknown bytes rather
than unknown bytes at unknown for
"http://bazaar.launchpad.net/%7Ebzr/bzr/bzr.1.6/.bzr/repository/indices/5a4f
2c46b38ea8f69400e7216da83b89.six": Server aborted the request during
http._readv
... <going again>
etc

Note the 15 minute gap before the 'got pycurl error: 18' messages.  If I'm
unlucky, I'll see a number of such errors in a single pull (I just got 2
pulling the 1.6 branch).  I've witnessed this problem on at least 2 machines
from different networks.  You see no indication that an error occurred -
unless you look at the log it just appears either bzr or launchpad is
excruciatingly slow.  Off the top of my head, I see at least 1 such error
every 3rd time pulling from Launchpad.

It seems to me that little network glitches aren't particularly unexpected -
but waiting 15 minutes when it happens isn't that friendly.  Is this
something specific to Windows?  Specific to pycurl?  Any suggestions about
what we can do to make such errors have less of an impact?

Thanks,

Mark