Configure your sessions in Redis for Magento 1

in Performance

Hypernodes bigger than grow, often have enough memory to store the session data in redis.
This way sessions are stored in-memory, making the shop faster and use less IO than when using mysql or files as session store.

Install Cm_RedisSession

First install the redis sessions plugin from gordon lesti to enable session storage in redis:

modman clone

Configure magento 1 to store your sessions in redis

To save your sessions for magento add/change the following settings in your local.xml:

Now flush your cache:

rm -rf /data/web/public/var/cache/* 
redis-cli flushall

Test whether your sessions are stored in redis

To verify whether your configuration is working properly, first clear your session store:

rm /data/web/public/var/sessions/*

Now open the site in your browser and hit F5 a few times or log in to the admin panel.
If all is well, no additional sessions files should be written to /data/web/var/sessions, but instead to the redis database:

redis-cli -n 2 keys \*