Do not collapse multiple servers when they resolve to the same IP

[saschat]

When I start XMemcached with multiple server strings that point to the same IP XMemcached will just create a single session.

For example if I have DNS-1 pointing to server-1 and DNS-2 also pointing to server-1 XMemcached will create one session to server-1. If I later point DNS-2 to server-2 and restart server-1 to bump off the connection XMemcached will only heal the session to server-1 but not create one to server-2.

The reason this is important is flexibility. I need to be able to reconfigure servers without having to change the client configuration or restart the client.

[saschat]

This is because the XMemcachedBuilder stores the addresses in protected Map<InetSocketAddress, InetSocketAddress> addressMap = new LinkedHashMap<InetSocketAddress, InetSocketAddress>();. Two InetSocketAddress with different hostnames that resolve to the same IP hash to the same value.