I have been trying to add another node to the cluster (after upgrading to 3.0.15) and I just noticed through "nodetool netstats" that all nodes have been streaming to the joining node approx 1/3 of their SSTables, basically their whole primary range (using RF=3)?
Is this expected/normal? I was under the impression only the necessary SSTables were going to be streamed... Thanks for the help, Stefano On Wed, Aug 23, 2017 at 1:37 PM, kurt greaves <k...@instaclustr.com> wrote: > But if it also streams, it means I'd still be under-pressure if I am not >> mistaken. I am under the assumption that the compactions are the by-product >> of streaming too many SStables at the same time, and not because of my >> current write load. >> > Ah yeah I wasn't thinking about the capacity problem, more of the > performance impact from the node being backed up with compactions. If you > haven't already, you should try disable stcs in l0 on the joining node. You > will likely still need to do a lot of compactions, but generally they > should be smaller. The option is -Dcassandra.disable_stcs_in_l0=true > >> I just noticed you were mentioning L1 tables too. Why would that affect >> the disk footprint? > > If you've been doing a lot of STCS in L0, you generally end up with some > large SSTables. These will eventually have to be compacted with L1. Could > also be suffering the problem of streamed SSTables causing large > cross-level compactions in the higher levels as well. > >
