The current default is 1024 however this is not sufficent for most
deployments and it will cause a lot of issues if it does hit the
limit as the server will stop responding.
The overhead for this is very low and other deployment tooling
usually sets this to 8192[1], so 4096 is even very conservative.
[1]: https://github.com/saz/puppet-memcached/blob/bb9d55a2/manifests/init.pp#L26
Change-Id: I604f96a9431076e1f630d2045eac4c88a92935c1
(cherry picked from commit d784ea1846)