If you work with Flask and have an under heavy load API, you can setup a cache for your endpoints. One of the tools is Flask- Cache that can work with different cache backends like Memcached, Redis, Simple, etc.

To install it:

pip install Flask-Cache

To setup up:

from flask import Flask
 from flask.ext.cache import Cache

 app = Flask(__name__)
 # Check Configuring Flask-Cache section for more details
 cache_config = {
     "CACHE_TYPE": "redis",
     "CACHE_REDIS_HOST": "127.0.0.1",
     "CACHE_REDIS_PORT": 6379,
     "CACHE_REDIS_DB": 3
 }
 cache = Cache(app,config=cache_config})

Another redis implementation:

#: the_app/custom.py
 class RedisCache(BaseCache):
     def __init__(self, servers, default_timeout=500):
         pass

 def redis(app, config, args, kwargs):
    args.append(app.config['REDIS_SERVERS'])
    return RedisCache(*args, **kwargs)

Now to use the cache on a method use its decorator:

@cache.memoize(timeout=50)
 def big_foo(a, b):
     return a + b + random.randrange(0, 1000)

#python #flask #cache #redis #memcached

Make your Django application blazing fast by doing some tips:

1- Use a separate media server:
Django deliberately doesn’t serve media for you, and it’s designed that way to save you from yourself. If you try to serve media from the same Apache instance that’s serving Django, you’re going to absolutely kill performance. Apache reuses processes between each request, so once a process caches all the code and libraries for Django, those stick around in memory. If you aren’t using that process to service a Django request, all the memory overhead is wasted.

So, set up all your media to be served by a different web server entirely. Ideally, this is a physically separate machine running a high- performance web server like lighttpd or tux. If you can’t afford the separate machine, at least have the media server be a separate process on the same machine.

For more information on how to separate static folder:
- https://docs.djangoproject.com/en/dev/howto/static-files/#howto-static-files


2- Use a separate database server:
If you can afford it, stick your database server on a separate machine, too. All too often Apache and PostgreSQL (or MySQL or whatever) compete for system resources in a bad way. A separate DB server — ideally one with lots of RAM and fast (10k or better) drives — will seriously improve the number of hits you can dish out.


3- Turn off KeepAlive:
I don’t totally understand how KeepAlive works, but turning it off on our Django servers increased performance by something like 50%. Of course, don’t do this if the same server is also serving media… but you’re not doing that, right?


4- Use memcached:
Although Django has support for a number of cache backends, none of them perform even half as well as memcached does. If you find yourself needing the cache, do yourself a favor and don’t even play around with the other backends; go straight for memcached.


#python #django #memcached

Those who are looking for scaling their cache server horizontally (redis/memcached) can use twemproxy. It is created by twitter:

https://github.com/twitter/twemproxy

#cache #redis #memcached #twemproxy