I'm a little confused by the "What about shared memory?" section here:
http://www.danga.com/memcached/ In particular, it says: "it's recommended you run both web nodes and memcached processes on the same machines. This way you'll save network ports." How does doing this save network ports? Is this referring to TCP/IP socket ports (i.e. as in HTTP on port 80?) Isn't the point of memcached that the cache is global across all machines, so each web node uses the memcached server on all the other web nodes? If each web node only used the local memcached (not the right thing to do?), then I can see how you save network ports. Otherwise, it seems to me you are using the same number of ports, just on different nodes than if you ran memcached on dedicated nodes. Does it mean you are saving physical ports on the switch/router, because you have fewer servers (why not just say you need fewer servers then?) Would be grateful if anyone can shed any light on this for me! -- Karl Harbour
