Profiling Python Programs

Profiling CPU/Time Usage

Here’s an example on how to profile xivo-ctid for CPU/time usage:

  1. Stop the monit daemon:

    service monit stop
  2. Stop the process you want to profile, i.e. xivo-ctid:

    service xivo-ctid stop
  3. Start the service in foreground mode running with the profiler:

    python -m cProfile -o test.profile /usr/bin/xivo-ctid -f

    This will create a file named test.profile when the process terminates.

    To profile xivo-confgend, you must use this command instead of the one above:

    twistd -p test.profile --profiler=cprofile --savestats -no --python=/usr/bin/xivo-confgend

    Note that profiling multi-threaded program (xivo-agid, xivo-confd) doesn’t work reliably.

    The Debugging Daemons section documents how to launch the various XiVO services in foreground/debug mode.

  4. Examine the result of the profiling:

    $ python -m pstats test.profile
    Welcome to the profile statistics browser.
    % sort time
    % stats 15
    % sort cumulative
    % stats 15

Measuring Code Coverage

Here’s an example on how to measure the code coverage of xivo-ctid.

This can be useful when you suspect a piece of code to be unused and you want to have additional information about it.

  1. Install the following packages:

    apt-get install python-pip build-essential python-dev
  2. Install coverage via pip:

    pip install coverage
  3. Run the program in foreground mode with coverage run:

    service monit stop
    service xivo-ctid stop
    coverage erase
    coverage run /usr/bin/xivo-ctid -f

    The Debugging Daemons section documents how to launch the various XiVO service in foreground/debug mode.

  4. After the process terminates, use coverage html to generate an HTML coverage report:

    coverage html --include='*xivo_cti*'

    This will generate an htlmcov directory in the current directory.

  5. Browse the coverage report.

    Either copy the directory onto your computer and open it with a web browser, or start a web server on the XiVO:

    cd htmlcov
    python -m SimpleHTTPServer

    Then open the page from your computer (i.e. not on the xivo):

    firefox http://<xivo-hostname>:8000