Hi Somnath, Thanks for sharing this information. And great to see bluestore with improved stability and performance. Which version of ceph were you running in this environment, latest master? Also it would be good to know the level of stability of the environment. Did ceph cluster broke after collection of this data? Thanks, Nitin > On Jul 27, 2016, at 8:40 AM, Somnath Roy <Somnath.Roy@xxxxxxxxxxx> wrote: > > As discussed in performance meeting, I am sharing the latest Bluestore tuning findings that is giving me better and most importantly stable result in my environment. > > Setup : > ------- > > 2 OSD nodes with 8 OSDs (on 8 TB SSD) each. > Single 4TB image (with exclusive lock disabled) from single client running 10 fio jobs and each job is with 128 QD. > Replication = 2. > Fio rbd ran for 30 min. > > Ceph.conf > ------------ > osd_op_num_threads_per_shard = 2 > osd_op_num_shards = 25 > > bluestore_rocksdb_options = "max_write_buffer_number=16,min_write_buffer_number_to_merge=2,recycle_log_file_num=16,compaction_threads=32,flusher_threads=8,max_background_compactions=32,max_background_flushes=8,max_bytes_for_level_base=5368709120,write_buffer_size=83886080,level0_file_num_compaction_trigger=4,level0_slowdown_writes_trigger=400,level0_stop_writes_trigger=800" > > rocksdb_cache_size = 4294967296 > bluestore_csum = false > bluestore_csum_type = none > bluestore_bluefs_buffered_io = false > bluestore_max_ops = 30000 > bluestore_max_bytes = 629145600 > bluestore_buffer_cache_size = 104857600 > bluestore_block_wal_size = 0 > > [osd.0] > host = emsnode12 > devs = /dev/sdb1 > #osd_journal = /dev/sdb1 > bluestore_block_db_path = /dev/sdb2 > #bluestore_block_wal_path = /dev/nvme0n1p1 > bluestore_block_wal_path = /dev/sdb3 > bluestore_block_path = /dev/sdb4 > > I have separate partition for block/db/wal.. > > Result: > -------- > No preconditioning of rbd images , started writing 4K RW from the beginning. > > Jobs: 10 (f=10): [w(10)] [100.0% done] [0KB/150.3MB/0KB /s] [0/38.5K/0 iops] [eta 00m:00s] > rbd_iodepth32: (groupid=0, jobs=10): err= 0: pid=883598: Fri Jul 22 19:43:41 2016 > write: io=282082MB, bw=160473KB/s, iops=40118, runt=1800007msec > slat (usec): min=25, max=2578, avg=51.73, stdev=15.99 > clat (usec): min=585, max=2096.7K, avg=3913.59, stdev=9871.73 > lat (usec): min=806, max=2096.7K, avg=3965.32, stdev=9871.71 > clat percentiles (usec): > | 1.00th=[ 1208], 5.00th=[ 1480], 10.00th=[ 1672], 20.00th=[ 1992], > | 30.00th=[ 2288], 40.00th=[ 2608], 50.00th=[ 2992], 60.00th=[ 3440], > | 70.00th=[ 4048], 80.00th=[ 4960], 90.00th=[ 6624], 95.00th=[ 8384], > | 99.00th=[15680], 99.50th=[25984], 99.90th=[55552], 99.95th=[64256], > | 99.99th=[87552] > bw (KB /s): min= 7, max=33864, per=10.08%, avg=16183.08, stdev=1401.82 > lat (usec) : 750=0.01%, 1000=0.10% > lat (msec) : 2=20.39%, 4=48.81%, 10=27.70%, 20=2.30%, 50=0.55% > lat (msec) : 100=0.14%, 250=0.01%, 2000=0.01%, >=2000=0.01% > cpu : usr=20.18%, sys=3.67%, ctx=96626924, majf=0, minf=166692 > IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=27.0%, 16=73.0%, 32=0.0%, >=64=0.0% > submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% > complete : 0=0.0%, 4=99.9%, 8=0.1%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0% > issued : total=r=0/w=72213031/d=0, short=r=0/w=0/d=0 > latency : target=0, window=0, percentile=100.00%, depth=16 > > *Significantly better latency/throughput than similar setup filestore*. > > > This is based on my experiment on all SSD , HDD case will be different. > Tuning also depends on your cpu complex/memory, I am running with 48 core (HT enabled) dual socket Xeon on each node with 64GB of memory.. > > Thanks & Regards > Somnath > > -----Original Message----- > From: Somnath Roy > Sent: Monday, July 11, 2016 8:04 AM > To: Mark Nelson (mnelson@xxxxxxxxxx) > Cc: 'ceph-devel@xxxxxxxxxxxxxxx' > Subject: Rocksdb tuning on Bluestore > > Mark, > With the following tuning it seems rocksdb is performing better in my environment. Basically, doing aggressive compaction to reduce the write stalls. > > bluestore_rocksdb_options = "max_write_buffer_number=16,min_write_buffer_number_to_merge=16,recycle_log_file_num=16,compaction_threads=32,flusher_threads=4,max_background_compactions=32,max_background_flushes=8,max_bytes_for_level_base=5368709120,write_buffer_size=83886080,level0_file_num_compaction_trigger=4,level0_slowdown_writes_trigger=400,level0_stop_writes_trigger=800" > > > BTW, I am not able to run BlueStore more than 2 hour at a stretch due to memory issues. It is filling up my system memory (2 node of 64 G memory , running 8 OSDS on each) fast. > The following operation I did and it started swapping. > > 1. Created a 4TB image and did 1M sequential preconditioning (took ~1 hour) > > 2. Followed by two 30 min 4k RW with QD 128 (numjob = 10) and in the 2nd run memory started swapping. > > Let me know how this rocksdb option works for you. > > Thanks & Regards > Somnath > > PLEASE NOTE: The information contained in this electronic mail message is intended only for the use of the designated recipient(s) named above. If the reader of this message is not the intended recipient, you are hereby notified that you have received this message in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. 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