Install Redis Caching for Magento

How to install redis for backend caching? You see alot of talk about using apc and memcached for Magento caching, but if you are looking for a more stable caching, then redis is for you.

1) Install Redis and phpRedis

This can be done using yum, which makes this step pretty easy.

yum install redis php-pecl-redis

service redis start

chkconfig redis on

Now to verify that redis is chkconfig on

chkconfig --list redis

2) Install Cm_Cache_Backend_Redis Magento Extension

This is the extension that is required on versions of CE 1.7.0.2 and older, as Magento 1.8.0.0 it comes pre installed.

wget -O Cm_Cache_Backend_Redis.tar.gz https://github.com/colinmollenhour/Cm_Cache_Backend_Redis/tarball/master

tar xzf Cm_Cache_Backend_Redis.tar.gz

cd colinmollenhour-Cm_Cache_Backend_Redis-*/

cp -r Cm /path/to/magento/app/code/local/

cp -r lib/Credis /path/to/magento/lib/

cat > /path/to/magento/app/etc/modules/Cm_Cache.xml <<eof
<?xml version="1.0" encoding="UTF-8"?>
<config>
   <modules>
       <Cm_Cache>
           <active>true</active>
           <codePool>local</codePool>
       </Cm_Cache>
   </modules>
</config>
eof

3) Install Credis Library

Again not needed if you are using Magento 1.8.0.0 or higher, as its already included in the base install

wget -O credis.tar.gz https://github.com/colinmollenhour/credis/tarball/master

tar xzf credis.tar.gz

cd colinmollenhour-credis-*/

cp -r ./* /path/to/magento/lib/Credis/

cd /path/to/magento/

chown -R username. lib/Credis/

chown -R username. app/code/local/Cm/

chown -R username. app/etc/modules/Cm_Cache.xml

4) Configure Magento to use Redis

Now comes the fun part, you are going to need to setup redis in your local.xml file.

I recommend always making a backup copy of your local.xml file before making any changes to it

cp app/etc/local.xml app/etc/local.xml-bk-$(date +%F)

Now lets install redis as a backend cache

vim app/etc/local.xml

Now add the following to your configuration for redis using TCP

<cache>
  <backend>Cm_Cache_Backend_Redis</backend>
  <backend_options>
    <server>127.0.0.1</server> 
    <port>6379</port>
    <persistent></persistent> 
    <password></password> 
    <force_standalone>0</force_standalone>  
    <connect_retries>1</connect_retries>    
    <read_timeout>10</read_timeout>         
    <automatic_cleaning_factor>0</automatic_cleaning_factor> 
    <compress_data>1</compress_data>  
    <compress_tags>1</compress_tags>  
    <compress_threshold>20480</compress_threshold>  
    <compression_lib>gzip</compression_lib> 
    <use_lua>0</use_lua> 
  </backend_options>
</cache>

If you are using a Socket for your redis instance

<cache>
  <backend>Cm_Cache_Backend_Redis</backend>
  <backend_options>
    <server>/var/tmp/redis-multi_path/to/my.sock</server> 
    <port></port>
    <persistent></persistent> 
    <password></password> 
    <force_standalone>0</force_standalone>  
    <connect_retries>1</connect_retries>    
    <read_timeout>10</read_timeout>         
    <automatic_cleaning_factor>0</automatic_cleaning_factor> 
    <compress_data>1</compress_data>  
    <compress_tags>1</compress_tags>  
    <compress_threshold>20480</compress_threshold>  
    <compression_lib>gzip</compression_lib> 
    <use_lua>0</use_lua> 
  </backend_options>
</cache>

Clearning your Magento Cache

Now the last step is a giving, any time you make any changes to your Magento configuration/template is to clear your sessions and cache. You do NOT want problems later, because you forgot to clear them and you now find a problem. Sometimes problems show their heads up to a week or so, so clear cache/session and see if you have any problems/issues.

If you were using files prior to the change

rm -r /path/magento/var/session/* /path/magento/var/cache/*

If you were using memcache prior to change

echo "flush_all" | nc 127.0.0.1 11211

or if using a sock

echo "flush_all" | nc -U /path/to/socket

How to flush your Redis Cache

Now you will want to flush your redis cache anytime you make a change to your site. The fastest way to do this is to run the following command via the command line.

echo 'flushall' | redis-cli -h 127.0.0.1 -p 6379

or

echo 'flushall' | redis-cli -s /path/to/sock

How to Check if your Redis Cache is Working

To verify you are getting connections to your redis instance

echo 'info' | redis-cli -h 127.0.0.1 -p 6379 | grep connections

or

echo 'info' | nc -U /path/to/socket | grep connections

Additioanl Articles

--> How to install Redis on a Centos 6.4 Server
--> Magento Connect is not Working
--> Changing the Minimum Search Query - MySQL Full Text Only
--> Install Redis Caching for Magento
--> Install Redis Full Page Caching for Magento Enterprise
--> Basic Redis commands - Cheat Sheet

Install Redis Caching for Magento

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