As someone who has been digging through a lot of job listings, I have a suggestion for those writing them:

Please, stop posting what you don’t want, and limit it to what you do.

I’ve been looking mostly for telecommute jobs, but when I search for telecommute along with other keywords, I find posting after posting saying “NO TELECOMMUTE” or similar – you’re only going to attract people looking for that keyword by posting it

If they just left it at “ON-SITE ONLY” it would not show up in a search for telecommute positions

So at work recently, we started looking at switching our django setups from mod_python to mod_wsgi, as we kept having memory and cpu use issues with mod_python, and mod_wsgi was supposed to be far better with performance.

Well, it’s only been a day so far, but the results have been very promising. Our memory usage was cut in half, and load bottomed out.

Edit: this is daemon mode with threads=1

Initial testing showed more drastic improvements, so for anyone else testing, take initial results with a grain of salt

With that said, here are the actual results:

Just after switching:

A day after switching:

Too early to be absolutely sure that everything is working well, but it’s all looking good so far

I really have to agree with John Cleese…

Not too long ago at work, we added a few more servers to our production deployment to speed things up – however, this made deploying code changes a bit more complicated, as you had to remember to update several servers every time.  I decided to look into Capistrano, which I’d heard about before, and am glad to say it’s working very well, once I managed to figure it out.

The only problem with Capistrano is that it’s primarily used by rails devs, so all the examples I could ever find online were using it for rails, and mostly using the included ‘deploy’ script, which is very rails-centric with migrations and such. Since we’re using python and javascript in our projects, those things didn’t apply well.

After some digging I’ve managed to get a nice little deploy script that will update many servers to the latest tag in svn, and can also roll back to the next-latest tag, in case something goes wrong

role :example, "www.example.com", "www2.example.com", "www3.example.com"

set :destination, "/home/example/sources"
set :repository, "svn+ssh://svn.example.com/svn/oggllc"

def ls(path)
    `svn ls #{path}`
end

def previous_tag(component)
    logger.debug "querying previous #{component} tag..."
    tags_dir = "#{repository}/tags/#{component}/"
    ls(tags_dir).split("\n")[-2].chomp('/')
end

def latest_tag(component)
    logger.debug "querying latest #{component} tag..."
    tags_dir = "#{repository}/tags/#{component}/"
    ls(tags_dir).split("\n")[-1].chomp('/')
end

desc "Deploy latest example tag"
task :deploy_example, :roles => :example do
    set :latest_rev, latest_tag("example")
    logger.debug "latest tag: #{latest_rev}"
    run "cd #{destination}/example ; svn switch #{repository}/tags/example/#{latest_rev}"
    run "sudo apachectl restart"
end

desc "Rollback example to previous tag"
task :rollback_example, :roles => :example do
    set :previous_rev, previous_tag("example")
    logger.debug "previous tag: #{previous_rev}"
    run "cd #{destination}/example ; svn switch #{repository}/tags/example/#{previous_rev}"
    run "sudo apachectl restart"
end

Not much text to put in this post, I just want to show a few useful things you can do with a ModelForm in django, so I can quit retyping examples

1) Replace a widget without losing all the default values passed to the form field from the model definition:

from django import forms
from mysite.polls.models import Poll

class PollForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        super(PollForm, self).__init__(*args, **kwargs)
        self.fields['question'].widget = forms.Textarea()

    class Meta:
        model = Poll

2) Along the same lines, limit the choices of a ForeignKey based on a user:

(assume we’ve added an owner field to the tutorial Poll model to indicate the User who created the Poll)

from datetime import datetime, timedelta
from django import forms
from mysite.polls.models import Poll, Choice

class ChoiceForm(forms.ModelForm):
    def __init__(self, user, *args, **kwargs):
        super(ChoiceForm, self).__init__(*args, **kwargs)
        self.fields['poll'].queryset = Poll.objects.filter(owner=user)

    class Meta:
        model = Choice

In this one, you would then call the form with request.user as the first argument:

form = ChoiceForm(request.user, request.POST)

or just

form = ChoiceForm(request.user)

3) Nothing yet, may expand this later.

Today my blog was hacked, erasing the most recent post in favor of spam links. Thankfully, I was able to recover it from Google’s cache, but I’m tired of all the issues maintaining my own blog.

As a result, I’ve decided to move my blog here, so that I don’t have to deal with the hassle anymore.