This is the list of servers that will updated when data is modified in the cache. Generally the fully qualified name of each server in the pool.
It **must** include the server listed in *Servers* above, even if by a different hostname.
Servers should be defined one per line and consist of a server address and optionally a port.
If no port is provided then the default port (11211) is used.

For example:
<pre>
server.url.com
ipaddress:port
</pre>