I am the programmer behind IvyLees The network for PR and business
and Presskit'n Do-It-Yourself Public Relations.
I developed the sites with django and also administrate the servers.
I am one of the developers in Match Strike: we build websites.
I haven’t gotten into caching and increasing performance of my application code itself; I was starting with the server. Thanks for the suggestion. When I do get around to speeding up slow parts of my code, I’ll keep Beaker in mind.
There are two more django apps that could help reduce http requests. I didn’t find these until after posting this. http://code.google.com/p/django-sprites/ and http://github.com/rnk/django-media-bundler/tree… will help create image sprites so that your css background images are all one file request. CSS sprites are explained in more detail here http://alistapart.com/articles/sprites
A lot of these steps will speed up any kind of application, not just django projects, but there are a few django specific things. Everything has been tested on
IvyLees which is running in a Debian/Ubuntu environment.
These three simple steps will speed up your server and allow it to handle more traffic.
Yahoo has developed a
firefox extension called
YSlow. It analyzes all of the traffic from a website and gives a score on a few categories where improvements can be made.
It recommends reducing all of your css files into one file and all of your js files into one file or as few as possible. There is a pluggable, open source django application available to help with that task. After setting up
django-compress, a website will have css and js files that are minified (excess white space and characters are removed to reduce file size). The application will also give the files version numbers so that they can be cached by the web browser and won’t need to be downloaded again until a change is made and a new version of the file is created.
How to setup the server to set a far future expiration is shown below in the lightweight server section.
Django makes it really simple to set up caching backends and memcached is easy to install.
sudo aptitude install memcached, python-setuptools
We will need setuptools so that we can do the following command.
sudo easy_install python-memcached
Once that is done you can start the memcached server by doing the following:
sudo memcached -d -u www-data -p 11211 -m 64
-d will start it in daemon mode, -u is the user for it to run as, -p is the port, and -m is the maximum number of megabytes of memory to use.
Now open up the settings.py file for your project and add the following line:
CACHE_BACKEND = 'memcached://127.0.0.1:11211/'
Find the MIDDLEWARE_CLASSES section and add this to the beginning of the list:
'django.middleware.cache.UpdateCacheMiddleware',
and this to the end of the list:
'django.middleware.cache.FetchFromCacheMiddleware',
For more about caching with django see the
django docs on caching. You can reload the server now to try it out.
sudo /etc/init.d/apache2 reload
To make sure that memcached is set up correctly you can telnet into it and get some statistics.
telnet localhost 11211
Once you are in type stats and it will show some information (press ctrl ] and then ctrl d to exit). If there are too many zeroes, it either isn’t working or you haven’t visited your site since the caching was set up. See
the memcached site for more information.
Apache has some overhead involved that makes it good for serving php, python, or ruby applications, but you do not need that for static files like your images, style sheets, and javascript. There are a few options for lightweight servers that you can put in front of apache to handle the static files.
Lighttpd (lighty) and
nginx (engine x) are two good options. Adding this layer in front of your application will act as an application firewall so there is a security bonus to the speed bonus.
There is this guide to
install a django setup with nginx and apache from scratch. If you followed
my guide to set up your server or already have apache set up for your application, then there are a few steps to get nginx handling your static files.
sudo aptitude install nginx
Edit the config file for your site (sudo nano /etc/apache2/sites-available/default) and change the port from 80 to 8080 and change the ip address (might be *) to 127.0.0.1. The lines will look like the following
NameVirtualHost 127.0.0.1:8080 <VirtualHost 127.0.0.1:8080>
Also edit the ports.conf file (sudo nano /etc/apache2/ports.conf) so that it will listen on 8080.
Listen 8080
Don’t restart the server yet, you want to configure nginx first. Edit the default nginx config file (sudo nano /etc/nginx/sites-available/default) and find where it says
location / {
root /var/www/nginx-default;
index index.html index.htm;
}
and replace it with
location / {
proxy_pass http://192.168.0.180:8080;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
client_max_body_size 10m;
client_body_buffer_size 128k;
proxy_connect_timeout 90;
proxy_send_timeout 90;
proxy_read_timeout 90;
proxy_buffer_size 4k;
proxy_buffers 4 32k;
proxy_busy_buffers_size 64k;
proxy_temp_file_write_size 64k;
}
location /files/ {
root /var/www/myproject/;
expires max;
}
/files/ is where I’ve stored all of my static files and /var/www/myproject/ is where my project lives and it contains the files directory.
Set static files to expire far in the future
expires max; will tell your users’ browsers to cache the files from that directory for a long time. Only use that if you are use those files won’t change. You can use expires 24h; if you aren’t sure.
Configure gzip
Edit the nginx configuration to use gzip on all of your static files (sudo nano /etc/nginx/nginx.conf). Where it says gzip on; make sure it looks like the following:
gzip on;
gzip_comp_level 2;
gzip_proxied any;
gzip_types text/plain text/html text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript;
The servers should be ready to be restarted.
sudo /etc/init.d/apache2 reload sudo /etc/init.d/nginx reload
If you are having any problems I suggest reading through
this guide and seeing if you have something set up differently.
Those three steps should speed up your server and allow for more simultaneous visitors. There is a lot more that can be done, but getting these three easy things out of the way first is a good start.
Related posts:
I don’t think there is anyway to do it in the database, but you can still put the logic in your application. If you are using django, there are signals that will help get that done. http://docs.djangoproject.com/en/1.0/topics/sig… If you aren’t then you will need to program it into your project in some other way.
It’s important to pay attention to what other hackers are doing in your area. One of the awesome things about silicon valley is all of the people from the startups hang out there, but there are hackers everywhere and there can be meetups anywhere.
Once I started paying attention to what was going on in Orlando I met a lot of smart people. We’re having a barcamp tomorrow too. http://www.barcamporlando.org/
There are other great things about silicon valley, but it’s not the only place with hackers.
That is something that I would probably buy. I’ve been thinking about living on a boat for about a year now and I haven’t really done any research. I’m sure there would be tons of information you could provide that would help.
That is a good post. I’ve been wanting to use nginx since you mentioned it 5 months ago and now I have no excuse for not using it.
In my
previous post I talk about reusable apps, but I don’t really explain it that much. If you have an app that might be useful in another project, it’s best to not refer to the project name in the application so you don’t have to search and remove it when adding to another project. To never refer to your project name in your app’s code, you will need to put your app on the python path. I usually do project_folder/apps/app_folder so apps will need to be a location that python is checking when you are importing so that importing looks like the following:
from appname.filename import foo
There are a few places you might need to add an apps folder to the pythonpath.
This will add the apps directory in your project directory to the beginning of the path list. This will allow manage.py syncdb and manage.py runserver to know that the apps folder should be added.
import os import sys PROJECT_ROOT = os.path.dirname(__file__) sys.path.insert(0, os.path.join(PROJECT_ROOT, "apps"))
That should be all you need to do to get most django projects working with your reusable apps, but if for any reason you need add to the path with mod python or mod wsgi, the following should work.
In the
setting-up-everything post I show an example httpd.conf file. In your apache configuration you will probably see something similar to what is below. To add the location /var/www/myproject/apps to the PythonPath I added it in the list.
SetHandler python-program PythonHandler django.core.handlers.modpython SetEnv DJANGO_SETTINGS_MODULE myproject.settings PythonOption django.root /myproject PythonDebug On PythonPath "['/var/www','/var/www/myproject/apps'] + sys.path"
If you use mod wsgi instead of mod python, your apache config will be loading a wsgi file with a line like this WSGIScriptAlias /var/www/myproject/myproject.wsgi. You will need to edit that file to add to the path (django’s site has an
example file).
sys.path.append('/var/www/myproject/apps')
You never know when you might want to use an app in another project, so always try to keep from mentioning the project name anywhere in the applications.
Related posts:
I found
one library that was linked everywhere, but it wasn’t working for me. I was always getting 400 Bad Request when using it. Chris Conover was able to get the following code working.
import urllib2 protocol = 'https://' url = 'example.com' command = '/projects.xml' headers = {'Accept' : 'application/xml', 'Content-type' : 'applications/xml'} username = 'x' password = 'y' # Setup password stuff passman = urllib2.HTTPPasswordMgrWithDefaultRealm() passman.add_password(None, url, username, password) authhandler = urllib2.HTTPBasicAuthHandler(passman) opener = urllib2.build_opener(authhandler) urllib2.install_opener(opener) # Send the request and get response req = urllib2.Request(protocol + url + command, None, headers) response = urllib2.urlopen(req) results = response.read() print results
I thought it was a problem with how the authorization was formed so based on the above code I modified the old basecamp.py file and I was able to get a response. The following is what I changed.
Around line 64
def __init__(self, username, password, protocol, url): self.baseURL = protocol+url if self.baseURL[-1] == '/': self.baseURL = self.baseURL[:-1] passman = urllib2.HTTPPasswordMgrWithDefaultRealm() passman.add_password(None, url, username, password) authhandler = urllib2.HTTPBasicAuthHandler(passman) self.opener = urllib2.build_opener(authhandler)
And around line 142
path = '/projects.xml'
With that I was able to use basecamp.py to retrieve a list of projects. Other modifications may be needed for other features, but that was all I planned on using.
Here is an example of using
ElementTree to parse the XML response to get the names of all of the projects returned from basecamp.
import elementtree.ElementTree as ET from basecamp import Basecamp protocol = 'https://' url = 'example.com' username = 'x' password = 'y' bc = Basecamp(username, password, protocol, url) projects = bc.projects() tree = ET.fromstring(projects) tags = tree.getiterator(tag='project') for t in tags: project_name = t.findtext('name')
Related posts:
Google finds new pages by following links when it crawls a currently indexed page. To get new pages showing in Google search results faster, websites can provide a sitemap.xml file that provides a link to every page on the site that should be in google’s index. In addition to that, websites can ping Google whenever the sitemap file is updated so that Google will know to check back and update its index.
We use the framework Django for ivylees.com and it provides an easy way to create sitemap files. Since the framework knows about all of our pages already, we only need to add a little bit of code to tell it how to generate the sitemap.xml file for us automatically. Django also makes it simple to ping google when there are updates.
With django we were able to make it as simple as possible for google to index new news releases as soon as possible.
