On Wednesday, August 13, 2014, Robert Coli <> wrote: > On Wed, Aug 13, 2014 at 5:53 AM, Ruchir Jha <[email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: > >> We are adding nodes currently and it seems like compression is falling >> behind. I judge that by the fact that the new node which has a 4.5T disk >> fills up to 100% while its bootstrapping. Can we avoid this problem with >> the LZ4 compressor because of better compression or do we just need a >> bigger disk? >> > > 2TB per node is a lot of data. 4.5 would be a huge amount of data. > Sure. Do you mean we should have started adding nodes before we got here? >
> Do you mean "compaction" is falling behind? Do you setcompactionthroughput > 0 while bootstrapping new nodes? > > I did a nodetool getcompactionthroughput and I got 0 MB/ s. It seems like that just disables compaction throttling which seems like a good thingin my scenario. Is that correct? > I don't think "compression" is involved here? Why do you think it does? > This is why I thought compression is involved: http://www.datastax.com/documentation/cassandra/1.2/cassandra/operations/ops_about_config_compress_c.html > Side note : we also increased number of concurrent compactors from 3 to 10. Because we had a lot of idle CPU lying around but that's not helping everytime we start bootstrapping we are still hitting 4.5 tb and them we run out of disk space. =Rob > >
