Question

I’ve got a buildout with django + wsgi that’s working nicely on dev and production. The only issue is that when I make a change or addition to the buildout.cfg and have to run bin/buildout, the website goes offline from the time buildout starts till the time it finishes. This can take upwards of 5 minutes.

Is there a way to run buildout gracefully in production? Maybe a parameter I’m unaware of that will run the buildout without uninstalling everything first? This site is running on one web server. A load balancer and extra web server would be a nice fix, but not feasible at this point.

Any other comments/suggestions/criticism on my buildout script are welcome.

Thanks!

Here’s my buildout.cfg:

[buildout]
download-cache = downloads
unzip = true
parts =
    scripts
    django
    djangoprod

eggs = 
    ${scripts:eggs} 
    ${pipscripts:eggs}

[scripts]
recipe = zc.recipe.egg
unzip = true
download-cache = ${buildout:download-cache}
eggs =
    ipython
    docutils
    feedparser
    pygments
    South
    django-grappelli
    django-extensions
    django-mobile
    django-photologue
    django-filebrowser
    django-indexer
    django-paging
    django-templatetag-sugar
    django-sentry
    MySQL-python

find-links =
    http://dist.repoze.org/
    http://github.com/
    http://bitbucket.org/
    http://googlecode.com/
    http://surfnet.dl.sourceforge.net/

[pipscripts]
recipe = gp.recipe.pip
unzip = true
download-cache = ${buildout:download-cache}
editables = 
    hg+https://bitbucket.org/ubernostrum/django-registration#egg=django_registration
    git://github.com/jtauber/django-mailer.git#egg=django_mailer
eggs = 
    django-registration
    django-mailer
    PIL
install =
    http://effbot.org/downloads/Imaging-1.1.7.tar.gz

[django]
recipe = djangorecipe
download-cache = ${buildout:download-cache}
eggs = ${buildout:eggs}
version = 1.3
project = project

[djangoprod]
recipe = djangorecipe
download-cache = ${django:download-cache}
version = ${django:version}
settings = production
wsgi = true
eggs = ${django:eggs}
project = ${django:project}

Answer 1

Buildout will only update parts where the configuration has changed (or in case of a stupid recipe implementation). One option is to copy/checkout the buildout configuration into a new location re-run buildout and then stop the old instance and then restart the instance on the new installation. In some case we maintain installations like

/data/buildout_<date1>
/data/buildout_<date2>
/data/current

where ‘current’ is a symlink to the current ‘buildout_’ installation.

And of course: running multiple instances behind a load-balancer where you take down an instance out of the balancer during the buildout phase is an option.