news from Brisbane

[Martin Pool]

Andrew and I are having a mini-sprint with Ian in Brisbane from Monday
through to Wednesday afternoon.

Yesterday we mostly dug into network performance pulling large
branches from Launchpad, focused on
<https://bugs.launchpad.net/bzr/+bug/582157>.  This is the somewhat
generic "pulling from Launchpad is slow" which at some point really
needs to be broken into more specific problems.  There is some
analysis in the bug which I won't repeat here.  It would be worth
continuing to pull on this for a while.

A couple of interesting tools:
 * perf - integrates into various interesting hardware and software
counters as a lower-level profiler; can for example count how many
hardware IOs were done during a command; useful as an adjunct to
strace and lsprof - shows us spending a lot of time in groupcompress
create_delta which seems a bit unnecessary if we're receiving data
already in the right format
 * tcptrace - makes a summary of behaviour in a pcap file, including
reporting on retransmissions and the longest lag between packets;
gives you a higher-level view than what you would get from wireshark

Andrew is patch pilot this week.  We might this morning have a go at
putting a test fixture pattern into testtools, then more on network
performance, then do a review of some ui issues with Ian.

-- 
Martin