INCOMPLETE DO NOT USE

Redis

Redis is an in memory data structure storage. It will be used to share PHP-sessions between the apache servers. To guarantee a robust deployment three redis servers will be configured.

Software

apt-get install redis-server redis-sentinel

Configuration

Redis Server

Make sure the apache servers can reach redis. Change bind 127.0.0.1 in /etc/redis/redis.conf. Each of the redis servers needs to listen on its own IP-address.

bind 127.0.0.1 192.168.1.58

Enable Redis to listen on the network

protected-mode no

Stop the redis server on all hosts.

service redis-server stop

To enable replication we need to consider one of the redis servers the master. Here it will be redis01. On the two other hosts add the following to /etc/redis/redis.conf.

slaveof 192.168.1.58 6379

Start the redis servers again, but start it on redis01 first.

service redis-server start

redis01 should now be the master.

Redis Sentinel

The same goes for /etc/redis/sentinel.conf

bind 127.0.0.1 192.168.1.58

References