Scalability with Membase
I have played around with Membase, added/removed Membase nodes in order to see a difference in the ability to respond to requests and can not work out why there is no difference.
My setup is 2 Nginx servers loadbalanced with Memcached clients for PHP and Moxi server client side. I have 3 Membase nodes.
If I do a simple serving (just echo "ok", 2 bytes document) I'm able to get 2551.39 requests per second.
If I do a (125 bytes document):
$m = new Memcached();
$m->addServer('localhost', 11211) or die ("Could not connect");
$rv = mt_rand();
$m->set($rv, array('user_id' => 1, 'url' => 'http://something', 'name' => $rv));
... I get 330-460 requests/second.
If I remove 1 Membase node I would assume that the cluster would not be able to handle as many request as before but to my surprise the 2 remaining nodes serve the same amount, how can that be?