Docker Memcached CentOS 6.6 + Memcached 1.4.22 Docker Image

That's nice, in Docker world slim = fast

My very first Docker image was a 699.8 MB CentminMod.07 image, with all services running inside the container ... I had no idea of what I was doing. It's still privately hosted at Quay.io. If you are interested in having a look, just let me know.

 

Just reading up on this as I'm exploring Docker a bit lately.

Your benchmarks are using two different networking stacks... For docker, you're using the default docker network proxy, which is great for network isolation, but really poor performance-wise because it's a userspace process. I suspect in this case it's the primary cause of slowness.

You should try exact same benchmarks using the flag `--network=host` when running your docker containers to tell docker to hook into IPTables for network layer. That way you're actually testing the difference between the memcache versions, not between loopback vs docker proxy networking.

 

I just ran redis-benchmark suite against docker redis 2.8 vs EPEL 2.8 installed directly in the VM. It's a KVM, so somewhat isolated to noisy neighbor, but definitely not the most scientific as I'm serving a small amount of live traffic on the box as well.

For the simple tests like SET GET etc docker-based was slower than I expected... but for longer tests they were mostly comparable.

So apparently there still is noticable network/switching overhead using Docker. Not anywhere near as bad as your memcache benchmarks above, but enough that it's probably 10%-20% to switch in/out, but once within the process it's equivalent.