Configure memcached

The following instructions tell you to make changes in your common configuration layer, because they are based on the assumption that you want all your Content Engines to share a common cache. If this is not the case, then the following actions should be carried out in the host configuration layers of the hosts you want to use memcached.

To configure memcached you need to add a .properties file to your common configuration layer.

Create a folder for the new properties file:

$ mkdir -p /etc/escenic/engine/common/com/danga/

Create a file called SockIOPool.properties in the new folder, open it for editing and add the following content:
```
$class=com.danga.MemCached.SockIOPool
# fill in memcached servers here.
servers=host-name1:11211,host-name2:11211

# how many connections to use
initConn = 10
minConn = 5
maxConn = 100
# idle time
maxIdle = 180000
maintSleep = 5000
# socket timeout
socketTO = 3000
failover = true
# a network lookup algorithm
nagle = false
```
where host-name1, host-name2, etc. are replaced by the names of the hosts on which you have installed memcached.

The above parameter settings should work satisfactorily in most cases. Should you need to modify them, consult the documentation available on the memcached web site (http://memcached.org/).
Open /etc/escenic/engine/common/Initial.properties for editing and add the following lines:
```
# using memcached
service.0.0-memcached-socket-pool=/com/danga/SockIOPool
```