How to use memcached to implement Django project caching

1. install memcached

Here we use Centos Take how to install as an example , Run the following command , install memcached

sudo yum install memcached

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Test for successful installation

memcached -help

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If no error is reported , It means that the installation is successful

2. function memcached

memcached -d -m 64 -l 127.0.0.1 -p 11211 -u root

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-d： Indicates that the daemon is started in the background

-m: Indicates how much memory is used , Use here 64M

-l： It's a listening server IP Address , Here we fill in the local , If you want other machines to access , It's written in 0.0.0.0

-p： It's the port number , The default is 11211

-u： Specify which user to run , Designated here root

see memcached Whether it runs successfully or not , Use the following command

ps -ef|grep memcached

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If the display is as shown in the figure below , Indicates successful startup

You can use the following command to turn off memcached process

killall -9 memcached

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3. Connect Memcached

Use telnet De link , Install first telnet, Following commands

sudo yum install telnet

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After installation , Use the following command to connect memcached

telnet 127.0.0.1 11211

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The following interface appears , Indicates successful connection , function quit Exit connection

thus , We installed it successfully memcached, And can run successfully , Let's introduce Django How the project uses it

4. install python-mamcached

In their own projects python Installation in environment , In the case of virtualization , Run the virtual environment before installing , The order is as follows

pip install python-memcached

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5. To configure Django project

In our project setting.py In the document , Join in CACHE Options , as follows

CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',
        'LOCATION': '127.0.0.1:11211',
    }
}

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Then according to the actual situation of your project , Set the required cache time , My personal Blog The cache time is set to one day , namely 60*60*24 second

CACHE_MIDDLEWARE_SECONDS=60*60*24

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Last , We are working on middleware MIDDLEWARE add to memcached what is needed Django middleware , Because I chose to cache the whole site , So the things we need are as follows ： Pay attention to the position and order of middleware

'django.middleware.cache.UpdateCacheMiddleware',#  Put it in the first place of the middleware 
 ...... #  Other middleware 
'django.middleware.cache.FetchFromCacheMiddleware',# Put it in the last position of the middleware 

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The above is all our configuration and installation , restart nginx and uwsgi Then you can open the website for speed measurement , It may be slow to open for the first time , Because you just put your request in the cache , When you open it again , Or open it within the cache time you just set , It's all on in seconds .

6. matters needing attention

Because we set up 24 Hour cache , So during the cache period , If you write a blog post , Your website won't show up immediately , Wait until the cache time expires , Will be updated , If you want to show it right away , You need to clean up the cache manually , Is the cache expired , The website will re cluster the database to get data , Manual cache expiration , Use the following command

#  Connect first memcached
telnet 127.0.0.1 11211

# Clear cache 
flush_all

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