sorry for reply so late, I knew the ardb and it's a great project. the function of the kvrocks and ardb seems to be similar, but it's architecture and the design goal were totally different, so the performance also different.
tcpkit allow the user to run have custom Lua parsers for different protocols. and the latency only works in redis/memcached mode, use `-m` to specify the mode, the default is raw, and the packet would pass to Lua VM. See the example in scripts dir. I would update the Lua to 5.3 later, or pr is welcome.
tcpkit offer embedded Redis/Memcached/DNS latency monitor, and export latency's data to the user, you can store it to influxdb and show latency buckets with grafana. we now use tcpkit to offer redis/memcached latency monitor.