I read in the docs that `nodetool repair` should be regularly run unless no
delete is ever performed. In my app, I never delete, but I heavily use the ttl
feature. Should repair still be run regularly? Also, does repair take less time
if it is run regularly? If not, is there a way to incrementally run it? It seems
that when I do run repair, it takes a long time and causes high amounts CPU
usage and iowait.