you can install the phpredis extension from the Ubuntu respositories.

First, if you don’t have it installed already, let’s install Redis:

sudo apt-get install redis-server

After we get Redis installed (and/or verified that it was installed), we can install the PHP module for Redis:

sudo apt-get install php5-redis

After the module is done installing, you will want to restart your webserver and/or process manager (php-fpm, spawncgi, et cetera). Once you’ve restarted, you can check phpinfo() for a new section labeled Redis.

On Ubuntu 14.x System, you may try:

Install Redis 2.8.9

sudo apt-add-repository ppa:chris-lea/redis-server
sudo apt-get update
sudo apt-get install redis-server

Remove Redis 2.8.9

sudo apt-get purge--auto-remove redis-server