I'm having problems understanding how incremental repairs are supposed to be run.
If I try to do "nodetool repair -inc" cassandra will complain that "It is not possible to mix sequential repair and incremental repairs". However it seems that running "nodetool repair -inc -par" does the job, but I couldn't be sure if this is the correct (and only?) way to run incremental repairs? Previously I ran repairs with "nodetool repair -pr" on each node at a time, so that I could minimise the performance hit. I've understood that doing a single "nodetool repair -inc -par" command runs it on all machines in the entire cluster, so doesn't that cause a big performance penalty? Can I run incremental repairs on one node at a time? If running "nodetool repair -inc -par" every night in a single node is fine, should I still spread them out so that each node takes a turn executing this command each night? Last question is a bit deeper: What I've understood is that incremental repairs don't do repairs on SSTables which have already been repaired, but doesn't this mean that these repaired SSTables can't be checked towards missing or incorrect data? Thanks.
