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. 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
