I am a bit confused about migration to incremental repairs in Cassandra, and how it impacts Leveled Compaction Strategy (LCS).
From this blog, it seems LCS uses STCS for unrepaired SSTables. But, there is a comment to clarify that- its no longer the case since 2.1.2. However, all the DataStax docs mention that- we need to follow a migration procedure if using incremental repair and LCS, as mentioned here. This seems to indicate that, while using LCS, we need to first do full sequential repairs, along with the use of sstablerepairedset utility to indicate what is repaired, before using incremental repairs.
My understanding from this link is that, these migration steps are needed only when using LCS, and that is to avoid LCS doing STCS on all SSTables, unless they are repaired. If we are using STCS, then these steps are not required.
The thing that is not clear to me is- if LCS is no longer using STCS for un-repaired tables, then what is the point of these migration steps.
Does that means that, no migration is needed, and we can just start using -inc option in repair commands without having to do steps mentioned here? Or, is there anything else I am missing, because of which we still need these migration steps?
I also checked that these steps are mentioned even for C* 3.0, and no where it says that- if you are on 2.1.2 or greater then these steps are not required. Can someone please clarify if I am missing anything?