Ubuntu 16.04 systemd redis issues with ulimit

Question

I have been having issues with our new redis server after swapping from Ubuntu 14.04 to 16.04. The configuration of the open files limit using all the guides says to change the

Answer 1

The sysctl values net.core.somaxconn and vm.overcommit_memory are note related to ulimit or the number of open files. They are related to:

• net.core.somaxconn: will limit the number of opened but not accepted connections.
  https://serverfault.com/questions/518862/will-increasing-net-core-somaxconn-make-a-difference
• vm.overcommit_memory: the policy to overcommit memory when physical memory is exausted.
  https://www.kernel.org/doc/Documentation/vm/overcommit-accounting

If your problem is with the limit of opened files (what ulimit -Sn/-Hn handles) then I would not suggest to play with this, unless you know exactly what you are doing.