It should work fine with num_tokens: 1 Without vnodes it also flushes to per-range sstables (if you have RF=3 you will "always" get 3 sstables after flush), while with vnodes it groups the ranges and flushes a full disk, so if you have a single data_file_directories you get only one sstable, then compaction will write them out to per-range sstables once they accumulates enough data.
/Marcus On Thu, Jul 19, 2018 at 11:34 PM Carl Mueller <carl.muel...@smartthings.com.invalid> wrote: > I don't want to comment on the 10540 ticket since it seems very well > focused on vnode-aligned sstable partitioning and compaction. I'm pretty > excited about that ticket. RACS should enable: > > - smaller scale LCS, more constrained I/O consumption > - less sstables to hit in read path > - multithreaded/multiprocessor compactions and even serving of data based > on individual vnode or pools of vnodes > - better alignment of tombstones with data they should be > nullifying/eventually removing > - repair streaming efficiency > - backups have more granularity for not uploading sstables that didn't > change for the range since last backup snapshot > > There is ongoing discussions as to using Priam for cluster management where > I am, and as I understand it (superficially) Priam does not use vnodes and > use manual tokens, and expands via node multiples. I believe it has certain > advantages over vnodes including expanding by multiple machines at once, > backups could possibly do (nodecount / RF) number of nodes for data backups > rather than the mess of vnodes where you have to do basically all of them. > > But we could still do some divisor split of the manual range and apply RACS > to that. I guess this would be vnode-lite. We could have some number like > 100 subranges on a node and expansion might just involve temporary lower > bound count of subranges until the sstables can be reprocessed to the > typical subrange count. > > Is this theoretically correct, or are there glaring things I might have > missed with respect to RACS-style compaction and manual tokens? >
