> Op 16 februari 2017 om 15:24 schreef Sage Weil <sweil@xxxxxxxxxx>: > > > On Thu, 16 Feb 2017, Ruiz Alonso, Jaime Jesus (Nokia - ES) wrote: > > > > Thanks a lot for your help, > > > > We left the test running with this change ( bluefs_buffered_io set to true ) > > and we observed a radical increase on performance. > > > > Effects of the change on our only write test: > > > > - No reads from disk ( before change were in the 500 r/s range ) > > - Minimum Write bandwidth moved from 12 MBps to 24 MBps > > > > Attached Sheet "Test1-2_Kraken_11.2_iotrue" in the xls. > > > > See attached pictures. > > > > Best Regards, > > Jaime > > Thanks for testing! This suggests to me that even a simple LRU write > buffer cache in bluefs to catch recently compacted SSTs will be enough to > prime the rocksdb kv cache. Either that or we need to do the same in > rocksdb itself, but they didn't seem very interested in doing that in the > general case. Our situation is a bit atypical in that we'd prefer to > eliminate the dependence on the OS page cache so that we can work with > SPDK. > What would be the true downside of setting bluefs_buffered_io to true in the default config? Wido > sage > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
