Benchmarking Memcached

Yet another key--value store written in C, but compared to Redis this one is multi-threaded.

Automated integration test

The easiest way to run memcached on nrk, is to invoke the integration test directly:

cd kernel
RUST_TEST_THREADS=1 cargo test --test s10* -- s10_memcached_benchmark

This test will spawn memcached on one, two and four threads and measure throughput and latency with memaslap.

Launch memcached manually

Start the server binary on the VM instance:

cd kernel
python3  \
    --kfeatures test-userspace-smp \
    --cmd 'log=info init=memcached.bin' \
    --nic virtio \
    --mods rkapps \
    --qemu-settings='-m 1024M' \
    --ufeatures 'rkapps:memcached' \
    --release \
    --qemu-cores 4 \

As usual, make sure dhcpd is running on the host:

cd kernel
sudo service apparmor teardown
sudo dhcpd -f -d tap0 --no-pid -cf ./tests/dhcpd.conf

Start the load-generater on the host:

memaslap -s -t 10s -S 10s

memaslap: Load generator

memaslap measures throughput and latency of a memcached instance. You can invoke it like this:

memaslap -s -B -S 1s

Explanation of arguments:

  • -B: Use the binary protocol (faster than the ASCII variant)
  • -S 1s: Dump statistics every X seconds

The other defaults arguments the tool assumes are:

  • 8 client threads with concurrency of 128 sockets
  • 1000000 requests
  • SET proportion: 10%
  • GET proportion: 90%

Unfortunately, the memaslap binary does not come with standard ubuntu packages. Follow the steps in the CI guide to install it from sources.