What version? Single disk or JBOD?
Vnodes? -- Jeff Jirsa > On Oct 15, 2017, at 12:49 PM, Stefano Ortolani <ostef...@gmail.com> wrote: > > Hi all, > > I have been trying "-Dcassandra.disable_stcs_in_l0=true", but no luck so far. > Based on the source code it seems that this option doesn't affect compactions > while bootstrapping. > > I am getting quite confused as it seems I am not able to bootstrap a node if > I don't have at least 6/7 times the disk space used by other nodes. > This is weird. The host I am bootstrapping is using a SSD. Also compaction > throughput is unthrottled (set to 0) and the compacting threads are set to 8. > Nevertheless, primary ranges from other nodes are being streamed, but data is > never compacted away. > > Does anybody know anything else I could try? > > Cheers, > Stefano > >> On Fri, Oct 13, 2017 at 3:58 PM, Stefano Ortolani <ostef...@gmail.com> wrote: >> Other little update: at the same time I see the number of pending tasks >> stuck (in this case at 1847); restarting the node doesn't help, so I can't >> really force the node to "digest" all those compactions. In the meanwhile >> the disk occupied is already twice the average load I have on other nodes. >> >> Feeling more and more puzzled here :S >> >>> On Fri, Oct 13, 2017 at 1:28 PM, Stefano Ortolani <ostef...@gmail.com> >>> wrote: >>> 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. >>>> >>> >> >
