launchpad-dev team mailing list archive

[Maris Fogels <maris.fogels@xxxxxxxxxxxxx>]

Hi everyone,

During the Epic Robert and I coded up and landed a patch that generates 
KCacheGrind profiles for launchpad requests.  KCacheGrind is a powerful tool for 
exploring call graphs, and this change should make it easier to see what pieces 
of Python are taking the most time to run.

To switch on profiling, add this to configs/development/launchpad-lazr.conf:


    [profiling]
    profile_requests: True


Then start the dev app server with 'make run', and use curl or wget to make 
*one* request to the URL you want:

    $ make run

    $ curl -k https://launchpad.dev/

    $ kcachegrind 
2010-07-20_10\:01\:46.680-RootObject\:index.html-OOPS-1662X1-Dummy-2.prof


Full instructions are here: https://dev.launchpad.net/Debugging.

For other teams that want to see how we hooked this feature into Zope, here is 
the patch: 
http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/11157

We don't have the magic '++profile++' URL on-demand profiling working yet.  That 
will come later.  Contributions towards it are welcome, feel free to ping me on 
IRC for the details.


Maris