Where can I set this?
The --smp option (for instance, --smp 2 ) will restrict Scylla to fewer CPUs. It will still use 100 % of those CPUs, but at least won’t take your system out completely. An analogous option exists for memory: -m .
Use these flags with care, ScyllaDB is optimized to use all the resources of the machine and not to be hosted on a machine that it running a different workload.
Also see the Best Practices for Running on Docker
documentation for more information about configuring resource limits.