On Dec 15, 1:44 pm, Alex Miller <[email protected]> wrote:
> While it is technically possible to have memcached servers available between > datacenters, there are a number of drawbacks to doing this. The first is the > security issue of having the server accessible outside on the public > internet. As memcached doesn't have authentication, anyone could potentially > connect to it. This can be avoided by using good firewall rules or a VPN / > dedicated link. The second is the latency introduced by pulling data across > the net then pushing it to the client. The latency increase could easily > exceed the speed benefit offered by memcached. memcached does have authentication, but the latency thing is the big part. The reasons one would add memcached to an infrastructure plan start falling off when you introduce WAN latency. You can synchronize caches across WANs somewhat and end up with a 2tier caching layer, but it's tricky to get right.
