>>Thanks for this great information.
>>We are using Firefly. We will also try this later. 
>>
>>Thanks
>>Jian

Oh, sorry,I have done a mistake when benching with fio (forgot to fill the osd 
with datas before the read benchmark).

true results with 6 osd : bw=118129KB/s, iops=29532 



----- Mail original ----- 

De: "Jian Zhang" <jian.zh...@intel.com> 
À: "Alexandre DERUMIER" <aderum...@odiso.com> 
Cc: ceph-users@lists.ceph.com 
Envoyé: Vendredi 19 Septembre 2014 10:21:38 
Objet: RE: [ceph-users] [Single OSD performance on SSD] Can't go over 3, 2K 
IOPS 

Thanks for this great information. 
We are using Firefly. We will also try this later. 

Thanks 
Jian 


-----Original Message----- 
From: Alexandre DERUMIER [mailto:aderum...@odiso.com] 
Sent: Friday, September 19, 2014 3:00 PM 
To: Zhang, Jian 
Cc: ceph-users@lists.ceph.com 
Subject: Re: [ceph-users] [Single OSD performance on SSD] Can't go over 3, 2K 
IOPS 

>>I'll do benchs with 6 osd dc3500 tomorrow to compare firefly and giant. 

Here the results (big giant improvements) 

3 nodes with 2osd, replication x1 
network is 2gigabit link with lacp for nodes and client 




firefly : no tunning 
--------------------- 
bw=45880KB/s, iops=11469 



firefly with tuning: 
-------------------- 
debug lockdep = 0/0 
debug context = 0/0 
debug crush = 0/0 
debug buffer = 0/0 
debug timer = 0/0 
debug journaler = 0/0 
debug osd = 0/0 
debug optracker = 0/0 
debug objclass = 0/0 
debug filestore = 0/0 
debug journal = 0/0 
debug ms = 0/0 
debug monc = 0/0 
debug tp = 0/0 
debug auth = 0/0 
debug finisher = 0/0 
debug heartbeatmap = 0/0 
debug perfcounter = 0/0 
debug asok = 0/0 
debug throttle = 0/0 
osd_op_threads = 5 
filestore_op_threads = 4 


bw=62094KB/s, iops=15523 



giant with same tuning 
----------------------- 
bw=247073KB/s, iops=61768 ! 

I think I could reach more, but my 2 gigabit link are satured. 



----- Mail original ----- 

De: "Alexandre DERUMIER" <aderum...@odiso.com> 
À: "Jian Zhang" <jian.zh...@intel.com> 
Cc: ceph-users@lists.ceph.com 
Envoyé: Jeudi 18 Septembre 2014 15:36:48 
Objet: Re: [ceph-users] [Single OSD performance on SSD] Can't go over 3, 2K 
IOPS 

>>Have anyone ever testing multi volume performance on a *FULL* SSD setup? 

I known that Stefan Priebe run full ssd clusters in production, and have done 
benchmark. (Ad far I remember, he have benched around 20k peak with dumpling) 

>>We are able to get ~18K IOPS for 4K random read on a single volume with fio 
>>(with rbd engine) on a 12x DC3700 Setup, but only able to get ~23K (peak) 
>>IOPS even with multiple volumes. 
>>Seems the maximum random write performance we can get on the entire cluster 
>>is quite close to single volume performance. 
Firefly or Giant ? 

I'll do benchs with 6 osd dc3500 tomorrow to compare firefly and giant. 

----- Mail original ----- 

De: "Jian Zhang" <jian.zh...@intel.com> 
À: "Sebastien Han" <sebastien....@enovance.com>, "Alexandre DERUMIER" 
<aderum...@odiso.com> 
Cc: ceph-users@lists.ceph.com 
Envoyé: Jeudi 18 Septembre 2014 08:12:32 
Objet: RE: [ceph-users] [Single OSD performance on SSD] Can't go over 3, 2K 
IOPS 

Have anyone ever testing multi volume performance on a *FULL* SSD setup? 
We are able to get ~18K IOPS for 4K random read on a single volume with fio 
(with rbd engine) on a 12x DC3700 Setup, but only able to get ~23K (peak) IOPS 
even with multiple volumes. 
Seems the maximum random write performance we can get on the entire cluster is 
quite close to single volume performance. 

Thanks 
Jian 


-----Original Message----- 
From: ceph-users [mailto:ceph-users-boun...@lists.ceph.com] On Behalf Of 
Sebastien Han 
Sent: Tuesday, September 16, 2014 9:33 PM 
To: Alexandre DERUMIER 
Cc: ceph-users@lists.ceph.com 
Subject: Re: [ceph-users] [Single OSD performance on SSD] Can't go over 3, 2K 
IOPS 

Hi, 

Thanks for keeping us updated on this subject. 
dsync is definitely killing the ssd. 

I don't have much to add, I'm just surprised that you're only getting 5299 with 
0.85 since I've been able to get 6,4K, well I was using the 200GB model, that 
might explain this. 


On 12 Sep 2014, at 16:32, Alexandre DERUMIER <aderum...@odiso.com> wrote: 

> here the results for the intel s3500 
> ------------------------------------ 
> max performance is with ceph 0.85 + optracker disabled. 
> intel s3500 don't have d_sync problem like crucial 
> 
> %util show almost 100% for read and write, so maybe the ssd disk performance 
> is the limit. 
> 
> I have some stec zeusram 8GB in stock (I used them for zfs zil), I'll try to 
> bench them next week. 
> 
> 
> 
> 
> 
> 
> INTEL s3500 
> ----------- 
> raw disk 
> -------- 
> 
> randread: fio --filename=/dev/sdb --direct=1 --rw=randread --bs=4k 
> --iodepth=32 --group_reporting --invalidate=0 --name=abc 
> --ioengine=aio bw=288207KB/s, iops=72051 
> 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await 
> w_await svctm %util 
> sdb 0,00 0,00 73454,00 0,00 293816,00 0,00 8,00 30,96 0,42 0,42 0,00 0,01 
> 99,90 
> 
> randwrite: fio --filename=/dev/sdb --direct=1 --rw=randwrite --bs=4k 
> --iodepth=32 --group_reporting --invalidate=0 --name=abc --ioengine=aio 
> --sync=1 bw=48131KB/s, iops=12032 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await 
> w_await svctm %util 
> sdb 0,00 0,00 0,00 24120,00 0,00 48240,00 4,00 2,08 0,09 0,00 0,09 0,04 
> 100,00 
> 
> 
> ceph 0.80 
> --------- 
> randread: no tuning: bw=24578KB/s, iops=6144 
> 
> 
> randwrite: bw=10358KB/s, iops=2589 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await 
> w_await svctm %util 
> sdb 0,00 373,00 0,00 8878,00 0,00 34012,50 7,66 1,63 0,18 0,00 0,18 0,06 
> 50,90 
> 
> 
> ceph 0.85 : 
> --------- 
> 
> randread : bw=41406KB/s, iops=10351 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await 
> w_await svctm %util 
> sdb 2,00 0,00 10425,00 0,00 41816,00 0,00 8,02 1,36 0,13 0,13 0,00 0,07 75,90 
> 
> randwrite : bw=17204KB/s, iops=4301 
> 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await 
> w_await svctm %util 
> sdb 0,00 333,00 0,00 9788,00 0,00 57909,00 11,83 1,46 0,15 0,00 0,15 0,07 
> 67,80 
> 
> 
> ceph 0.85 tuning op_tracker=false 
> ---------------- 
> 
> randread : bw=86537KB/s, iops=21634 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await 
> w_await svctm %util 
> sdb 25,00 0,00 21428,00 0,00 86444,00 0,00 8,07 3,13 0,15 0,15 0,00 0,05 
> 98,00 
> 
> randwrite: bw=21199KB/s, iops=5299 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await 
> w_await svctm %util 
> sdb 0,00 1563,00 0,00 9880,00 0,00 75223,50 15,23 2,09 0,21 0,00 0,21 0,07 
> 80,00 
> 
> 
> ----- Mail original ----- 
> 
> De: "Alexandre DERUMIER" <aderum...@odiso.com> 
> À: "Cedric Lemarchand" <ced...@yipikai.org> 
> Cc: ceph-users@lists.ceph.com 
> Envoyé: Vendredi 12 Septembre 2014 08:15:08 
> Objet: Re: [ceph-users] [Single OSD performance on SSD] Can't go over 
> 3, 2K IOPS 
> 
> results of fio on rbd with kernel patch 
> 
> 
> 
> fio rbd crucial m550 1 osd 0.85 (osd_enable_op_tracker true or false, same 
> result): 
> --------------------------- 
> bw=12327KB/s, iops=3081 
> 
> So no much better than before, but this time, iostat show only 15% 
> utils, and latencies are lower 
> 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await 
> r_await w_await svctm %util sdb 0,00 29,00 0,00 3075,00 0,00 36748,50 
> 23,90 0,29 0,10 0,00 0,10 0,05 15,20 
> 
> 
> So, the write bottleneck seem to be in ceph. 
> 
> 
> 
> I will send s3500 result today 
> 
> ----- Mail original ----- 
> 
> De: "Alexandre DERUMIER" <aderum...@odiso.com> 
> À: "Cedric Lemarchand" <ced...@yipikai.org> 
> Cc: ceph-users@lists.ceph.com 
> Envoyé: Vendredi 12 Septembre 2014 07:58:05 
> Objet: Re: [ceph-users] [Single OSD performance on SSD] Can't go over 
> 3, 2K IOPS 
> 
>>> For crucial, I'll try to apply the patch from stefan priebe, to 
>>> ignore flushes (as crucial m550 have supercaps) 
>>> http://lists.ceph.com/pipermail/ceph-users-ceph.com/2013-November/03 
>>> 5707.html 
> Here the results, disable cache flush 
> 
> crucial m550 
> ------------ 
> #fio --filename=/dev/sdb --direct=1 --rw=write --bs=4k --numjobs=2 
> --group_reporting --invalidate=0 --name=ab --sync=1 bw=177575KB/s, 
> iops=44393 
> 
> 
> ----- Mail original ----- 
> 
> De: "Alexandre DERUMIER" <aderum...@odiso.com> 
> À: "Cedric Lemarchand" <ced...@yipikai.org> 
> Cc: ceph-users@lists.ceph.com 
> Envoyé: Vendredi 12 Septembre 2014 04:55:21 
> Objet: Re: [ceph-users] [Single OSD performance on SSD] Can't go over 
> 3, 2K IOPS 
> 
> Hi, 
> seem that intel s3500 perform a lot better with o_dsync 
> 
> crucial m550 
> ------------ 
> #fio --filename=/dev/sdb --direct=1 --rw=write --bs=4k --numjobs=2 
> --group_reporting --invalidate=0 --name=ab --sync=1 bw=1249.9KB/s, 
> iops=312 
> 
> intel s3500 
> ----------- 
> fio --filename=/dev/sdb --direct=1 --rw=write --bs=4k --numjobs=2 
> --group_reporting --invalidate=0 --name=ab --sync=1 #bw=41794KB/s, 
> iops=10448 
> 
> ok, so 30x faster. 
> 
> 
> 
> For crucial, I have try to apply the patch from stefan priebe, to 
> ignore flushes (as crucial m550 have supercaps) 
> http://lists.ceph.com/pipermail/ceph-users-ceph.com/2013-November/0357 
> 07.html Coming from zfs, this sound like "zfs_nocacheflush" 
> 
> Now results: 
> 
> crucial m550 
> ------------ 
> #fio --filename=/dev/sdb --direct=1 --rw=write --bs=4k --numjobs=2 
> --group_reporting --invalidate=0 --name=ab --sync=1 bw=177575KB/s, 
> iops=44393 
> 
> 
> 
> fio rbd crucial m550 1 osd 0.85 (osd_enable_op_tracker true or false, same 
> result): 
> --------------------------- 
> bw=12327KB/s, iops=3081 
> 
> So no much better than before, but this time, iostat show only 15% 
> utils, and latencies are lower 
> 
> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await 
> r_await w_await svctm %util sdb 0,00 29,00 0,00 3075,00 0,00 36748,50 
> 23,90 0,29 0,10 0,00 0,10 0,05 15,20 
> 
> 
> So, the write bottleneck seem to be in ceph. 
> 
> 
> 
> I will send s3500 result today 
> 
> ----- Mail original ----- 
> 
> De: "Cedric Lemarchand" <ced...@yipikai.org> 
> À: ceph-users@lists.ceph.com 
> Envoyé: Jeudi 11 Septembre 2014 21:23:23 
> Objet: Re: [ceph-users] [Single OSD performance on SSD] Can't go over 
> 3, 2K IOPS 
> 
> 
> Le 11/09/2014 19:33, Cedric Lemarchand a écrit : 
>> Le 11/09/2014 08:20, Alexandre DERUMIER a écrit : 
>>> Hi Sebastien, 
>>> 
>>> here my first results with crucial m550 (I'll send result with intel s3500 
>>> later): 
>>> 
>>> - 3 nodes 
>>> - dell r620 without expander backplane 
>>> - sas controller : lsi LSI 9207 (no hardware raid or cache) 
>>> - 2 x E5-2603v2 1.8GHz (4cores) 
>>> - 32GB ram 
>>> - network : 2xgigabit link lacp + 2xgigabit lacp for cluster replication. 
>>> 
>>> -os : debian wheezy, with kernel 3.10 
>>> 
>>> os + ceph mon : 2x intel s3500 100gb linux soft raid osd : crucial 
>>> m550 (1TB). 
>>> 
>>> 
>>> 3mon in the ceph cluster, 
>>> and 1 osd (journal and datas on same disk) 
>>> 
>>> 
>>> ceph.conf 
>>> --------- 
>>> debug_lockdep = 0/0 
>>> debug_context = 0/0 
>>> debug_crush = 0/0 
>>> debug_buffer = 0/0 
>>> debug_timer = 0/0 
>>> debug_filer = 0/0 
>>> debug_objecter = 0/0 
>>> debug_rados = 0/0 
>>> debug_rbd = 0/0 
>>> debug_journaler = 0/0 
>>> debug_objectcatcher = 0/0 
>>> debug_client = 0/0 
>>> debug_osd = 0/0 
>>> debug_optracker = 0/0 
>>> debug_objclass = 0/0 
>>> debug_filestore = 0/0 
>>> debug_journal = 0/0 
>>> debug_ms = 0/0 
>>> debug_monc = 0/0 
>>> debug_tp = 0/0 
>>> debug_auth = 0/0 
>>> debug_finisher = 0/0 
>>> debug_heartbeatmap = 0/0 
>>> debug_perfcounter = 0/0 
>>> debug_asok = 0/0 
>>> debug_throttle = 0/0 
>>> debug_mon = 0/0 
>>> debug_paxos = 0/0 
>>> debug_rgw = 0/0 
>>> osd_op_threads = 5 
>>> filestore_op_threads = 4 
>>> 
>>> ms_nocrc = true 
>>> cephx sign messages = false 
>>> cephx require signatures = false 
>>> 
>>> ms_dispatch_throttle_bytes = 0 
>>> 
>>> #0.85 
>>> throttler_perf_counter = false 
>>> filestore_fd_cache_size = 64 
>>> filestore_fd_cache_shards = 32 
>>> osd_op_num_threads_per_shard = 1 
>>> osd_op_num_shards = 25 
>>> osd_enable_op_tracker = true 
>>> 
>>> 
>>> 
>>> Fio disk 4K benchmark 
>>> ------------------ 
>>> rand read 4k : fio --filename=/dev/sdb --direct=1 --rw=randread 
>>> --bs=4k --iodepth=32 --group_reporting --invalidate=0 --name=abc 
>>> --ioengine=aio bw=271755KB/s, iops=67938 
>>> 
>>> rand write 4k : fio --filename=/dev/sdb --direct=1 --rw=randwrite 
>>> --bs=4k --iodepth=32 --group_reporting --invalidate=0 --name=abc 
>>> --ioengine=aio bw=228293KB/s, iops=57073 
>>> 
>>> 
>>> 
>>> fio osd benchmark (through librbd) 
>>> ---------------------------------- 
>>> [global] 
>>> ioengine=rbd 
>>> clientname=admin 
>>> pool=test 
>>> rbdname=test 
>>> invalidate=0 # mandatory 
>>> rw=randwrite 
>>> rw=randread 
>>> bs=4k 
>>> direct=1 
>>> numjobs=4 
>>> group_reporting=1 
>>> 
>>> [rbd_iodepth32] 
>>> iodepth=32 
>>> 
>>> 
>>> 
>>> FIREFLY RESULTS 
>>> ---------------- 
>>> fio randwrite : bw=5009.6KB/s, iops=1252 
>>> 
>>> fio randread: bw=37820KB/s, iops=9455 
>>> 
>>> 
>>> 
>>> O.85 RESULTS 
>>> ------------ 
>>> 
>>> fio randwrite : bw=11658KB/s, iops=2914 
>>> 
>>> fio randread : bw=38642KB/s, iops=9660 
>>> 
>>> 
>>> 
>>> 0.85 + osd_enable_op_tracker=false 
>>> ----------------------------------- 
>>> fio randwrite : bw=11630KB/s, iops=2907 fio randread : bw=80606KB/s, 
>>> iops=20151, (cpu 100% - GREAT !) 
>>> 
>>> 
>>> 
>>> So, for read, seem that osd_enable_op_tracker is the bottleneck. 
>>> 
>>> 
>>> Now for write, I really don't understand why it's so low. 
>>> 
>>> 
>>> I have done some iostat: 
>>> 
>>> 
>>> FIO directly on /dev/sdb 
>>> bw=228293KB/s, iops=57073 
>>> 
>>> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await 
>>> r_await w_await svctm %util sdb 0,00 0,00 0,00 63613,00 0,00 
>>> 254452,00 8,00 31,24 0,49 0,00 0,49 0,02 100,00 
>>> 
>>> 
>>> FIO directly on osd through librbd 
>>> bw=11658KB/s, iops=2914 
>>> 
>>> Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await 
>>> r_await w_await svctm %util sdb 0,00 355,00 0,00 5225,00 0,00 
>>> 29678,00 11,36 57,63 11,03 0,00 11,03 0,19 99,70 
>>> 
>>> 
>>> (I don't understand what exactly is %util, 100% in the 2 cases, 
>>> because 10x slower with ceph) 
>> It would be interesting if you could catch the size of writes on SSD 
>> during the bench through librbd (I know nmon can do that) 
> Replying to myself ... I ask a bit quickly in the way we already have 
> this information (29678 / 5225 = 5,68Ko), but this is irrelevant. 
> 
> Cheers 
> 
>>> It could be a dsync problem, result seem pretty poor 
>>> 
>>> # dd if=rand.file of=/dev/sdb bs=4k count=65536 oflag=direct 
>>> 65536+0 enregistrements lus 
>>> 65536+0 enregistrements écrits 
>>> 268435456 octets (268 MB) copiés, 2,77433 s, 96,8 MB/s 
>>> 
>>> 
>>> # dd if=rand.file of=/dev/sdb bs=4k count=65536 oflag=dsync,direct 
>>> ^C17228+0 enregistrements lus 
>>> 17228+0 enregistrements écrits 
>>> 70565888 octets (71 MB) copiés, 70,4098 s, 1,0 MB/s 
>>> 
>>> 
>>> 
>>> I'll do tests with intel s3500 tomorrow to compare 
>>> 
>>> ----- Mail original ----- 
>>> 
>>> De: "Sebastien Han" <sebastien....@enovance.com> 
>>> À: "Warren Wang" <warren_w...@cable.comcast.com> 
>>> Cc: ceph-users@lists.ceph.com 
>>> Envoyé: Lundi 8 Septembre 2014 22:58:25 
>>> Objet: Re: [ceph-users] [Single OSD performance on SSD] Can't go 
>>> over 3, 2K IOPS 
>>> 
>>> They definitely are Warren! 
>>> 
>>> Thanks for bringing this here :). 
>>> 
>>> On 05 Sep 2014, at 23:02, Wang, Warren <warren_w...@cable.comcast.com> 
>>> wrote: 
>>> 
>>>> +1 to what Cedric said. 
>>>> 
>>>> Anything more than a few minutes of heavy sustained writes tended to get 
>>>> our solid state devices into a state where garbage collection could not 
>>>> keep up. Originally we used small SSDs and did not overprovision the 
>>>> journals by much. Manufacturers publish their SSD stats, and then in very 
>>>> small font, state that the attained IOPS are with empty drives, and the 
>>>> tests are only run for very short amounts of time. Even if the drives are 
>>>> new, it's a good idea to perform an hdparm secure erase on them (so that 
>>>> the SSD knows that the blocks are truly unused), and then overprovision 
>>>> them. You'll know if you have a problem by watching for utilization and 
>>>> wait data on the journals. 
>>>> 
>>>> One of the other interesting performance issues is that the Intel 10Gbe 
>>>> NICs + default kernel that we typically use max out around 1million 
>>>> packets/sec. It's worth tracking this metric to if you are close. 
>>>> 
>>>> I know these aren't necessarily relevant to the test parameters you gave 
>>>> below, but they're worth keeping in mind. 
>>>> 
>>>> -- 
>>>> Warren Wang 
>>>> Comcast Cloud (OpenStack) 
>>>> 
>>>> 
>>>> From: Cedric Lemarchand <ced...@yipikai.org> 
>>>> Date: Wednesday, September 3, 2014 at 5:14 PM 
>>>> To: "ceph-users@lists.ceph.com" <ceph-users@lists.ceph.com> 
>>>> Subject: Re: [ceph-users] [Single OSD performance on SSD] Can't go 
>>>> over 3, 2K IOPS 
>>>> 
>>>> 
>>>> Le 03/09/2014 22:11, Sebastien Han a écrit : 
>>>>> Hi Warren, 
>>>>> 
>>>>> What do mean exactly by secure erase? At the firmware level with 
>>>>> constructor softwares? 
>>>>> SSDs were pretty new so I don't we hit that sort of things. I believe 
>>>>> that only aged SSDs have this behaviour but I might be wrong. 
>>>>> 
>>>> Sorry I forgot to reply to the real question ;-) So yes it only 
>>>> plays after some times, for your case, if the SSD still delivers write 
>>>> IOPS specified by the manufacturer, it will doesn't help in any ways. 
>>>> 
>>>> But it seems this practice is nowadays increasingly used. 
>>>> 
>>>> Cheers 
>>>>> On 02 Sep 2014, at 18:23, Wang, Warren 
>>>>> <warren_w...@cable.comcast.com> 
>>>>> wrote: 
>>>>> 
>>>>> 
>>>>>> Hi Sebastien, 
>>>>>> 
>>>>>> Something I didn't see in the thread so far, did you secure erase the 
>>>>>> SSDs before they got used? I assume these were probably repurposed for 
>>>>>> this test. We have seen some pretty significant garbage collection issue 
>>>>>> on various SSD and other forms of solid state storage to the point where 
>>>>>> we are overprovisioning pretty much every solid state device now. By as 
>>>>>> much as 50% to handle sustained write operations. Especially important 
>>>>>> for the journals, as we've found. 
>>>>>> 
>>>>>> Maybe not an issue on the short fio run below, but certainly evident on 
>>>>>> longer runs or lots of historical data on the drives. The max 
>>>>>> transaction time looks pretty good for your test. Something to consider 
>>>>>> though. 
>>>>>> 
>>>>>> Warren 
>>>>>> 
>>>>>> -----Original Message----- 
>>>>>> From: ceph-users [ 
>>>>>> mailto:ceph-users-boun...@lists.ceph.com 
>>>>>> ] On Behalf Of Sebastien Han 
>>>>>> Sent: Thursday, August 28, 2014 12:12 PM 
>>>>>> To: ceph-users 
>>>>>> Cc: Mark Nelson 
>>>>>> Subject: [ceph-users] [Single OSD performance on SSD] Can't go 
>>>>>> over 3, 2K IOPS 
>>>>>> 
>>>>>> Hey all, 
>>>>>> 
>>>>>> It has been a while since the last thread performance related on the ML 
>>>>>> :p I've been running some experiment to see how much I can get from an 
>>>>>> SSD on a Ceph cluster. 
>>>>>> To achieve that I did something pretty simple: 
>>>>>> 
>>>>>> * Debian wheezy 7.6 
>>>>>> * kernel from debian 3.14-0.bpo.2-amd64 
>>>>>> * 1 cluster, 3 mons (i'd like to keep this realistic since in a 
>>>>>> real deployment i'll use 3) 
>>>>>> * 1 OSD backed by an SSD (journal and osd data on the same 
>>>>>> device) 
>>>>>> * 1 replica count of 1 
>>>>>> * partitions are perfectly aligned 
>>>>>> * io scheduler is set to noon but deadline was showing the same 
>>>>>> results 
>>>>>> * no updatedb running 
>>>>>> 
>>>>>> About the box: 
>>>>>> 
>>>>>> * 32GB of RAM 
>>>>>> * 12 cores with HT @ 2,4 GHz 
>>>>>> * WB cache is enabled on the controller 
>>>>>> * 10Gbps network (doesn't help here) 
>>>>>> 
>>>>>> The SSD is a 200G Intel DC S3700 and is capable of delivering around 29K 
>>>>>> iops with random 4k writes (my fio results) As a benchmark tool I used 
>>>>>> fio with the rbd engine (thanks deutsche telekom guys!). 
>>>>>> 
>>>>>> O_DIECT and D_SYNC don't seem to be a problem for the SSD: 
>>>>>> 
>>>>>> # dd if=/dev/urandom of=rand.file bs=4k count=65536 
>>>>>> 65536+0 records in 
>>>>>> 65536+0 records out 
>>>>>> 268435456 bytes (268 MB) copied, 29.5477 s, 9.1 MB/s 
>>>>>> 
>>>>>> # du -sh rand.file 
>>>>>> 256M rand.file 
>>>>>> 
>>>>>> # dd if=rand.file of=/dev/sdo bs=4k count=65536 
>>>>>> oflag=dsync,direct 
>>>>>> 65536+0 records in 
>>>>>> 65536+0 records out 
>>>>>> 268435456 bytes (268 MB) copied, 2.73628 s, 98.1 MB/s 
>>>>>> 
>>>>>> See my ceph.conf: 
>>>>>> 
>>>>>> [global] 
>>>>>> auth cluster required = cephx 
>>>>>> auth service required = cephx 
>>>>>> auth client required = cephx 
>>>>>> fsid = 857b8609-8c9b-499e-9161-2ea67ba51c97 
>>>>>> osd pool default pg num = 4096 
>>>>>> osd pool default pgp num = 4096 
>>>>>> osd pool default size = 2 
>>>>>> osd crush chooseleaf type = 0 
>>>>>> 
>>>>>> debug lockdep = 0/0 
>>>>>> debug context = 0/0 
>>>>>> debug crush = 0/0 
>>>>>> debug buffer = 0/0 
>>>>>> debug timer = 0/0 
>>>>>> debug journaler = 0/0 
>>>>>> debug osd = 0/0 
>>>>>> debug optracker = 0/0 
>>>>>> debug objclass = 0/0 
>>>>>> debug filestore = 0/0 
>>>>>> debug journal = 0/0 
>>>>>> debug ms = 0/0 
>>>>>> debug monc = 0/0 
>>>>>> debug tp = 0/0 
>>>>>> debug auth = 0/0 
>>>>>> debug finisher = 0/0 
>>>>>> debug heartbeatmap = 0/0 
>>>>>> debug perfcounter = 0/0 
>>>>>> debug asok = 0/0 
>>>>>> debug throttle = 0/0 
>>>>>> 
>>>>>> [mon] 
>>>>>> mon osd down out interval = 600 
>>>>>> mon osd min down reporters = 13 
>>>>>> [mon.ceph-01] 
>>>>>> host = ceph-01 
>>>>>> mon addr = 172.20.20.171 
>>>>>> [mon.ceph-02] 
>>>>>> host = ceph-02 
>>>>>> mon addr = 172.20.20.172 
>>>>>> [mon.ceph-03] 
>>>>>> host = ceph-03 
>>>>>> mon addr = 172.20.20.173 
>>>>>> 
>>>>>> debug lockdep = 0/0 
>>>>>> debug context = 0/0 
>>>>>> debug crush = 0/0 
>>>>>> debug buffer = 0/0 
>>>>>> debug timer = 0/0 
>>>>>> debug journaler = 0/0 
>>>>>> debug osd = 0/0 
>>>>>> debug optracker = 0/0 
>>>>>> debug objclass = 0/0 
>>>>>> debug filestore = 0/0 
>>>>>> debug journal = 0/0 
>>>>>> debug ms = 0/0 
>>>>>> debug monc = 0/0 
>>>>>> debug tp = 0/0 
>>>>>> debug auth = 0/0 
>>>>>> debug finisher = 0/0 
>>>>>> debug heartbeatmap = 0/0 
>>>>>> debug perfcounter = 0/0 
>>>>>> debug asok = 0/0 
>>>>>> debug throttle = 0/0 
>>>>>> 
>>>>>> [osd] 
>>>>>> osd mkfs type = xfs 
>>>>>> osd mkfs options xfs = -f -i size=2048 osd mount options xfs = 
>>>>>> rw,noatime,logbsize=256k,delaylog osd journal size = 20480 
>>>>>> cluster_network = 172.20.20.0/24 public_network = 172.20.20.0/24 
>>>>>> osd mon heartbeat interval = 30 # Performance tuning filestore 
>>>>>> merge threshold = 40 filestore split multiple = 8 osd op threads 
>>>>>> = 8 # Recovery tuning osd recovery max active = 1 osd max 
>>>>>> backfills = 1 osd recovery op priority = 1 
>>>>>> 
>>>>>> 
>>>>>> debug lockdep = 0/0 
>>>>>> debug context = 0/0 
>>>>>> debug crush = 0/0 
>>>>>> debug buffer = 0/0 
>>>>>> debug timer = 0/0 
>>>>>> debug journaler = 0/0 
>>>>>> debug osd = 0/0 
>>>>>> debug optracker = 0/0 
>>>>>> debug objclass = 0/0 
>>>>>> debug filestore = 0/0 
>>>>>> debug journal = 0/0 
>>>>>> debug ms = 0/0 
>>>>>> debug monc = 0/0 
>>>>>> debug tp = 0/0 
>>>>>> debug auth = 0/0 
>>>>>> debug finisher = 0/0 
>>>>>> debug heartbeatmap = 0/0 
>>>>>> debug perfcounter = 0/0 
>>>>>> debug asok = 0/0 
>>>>>> debug throttle = 0/0 
>>>>>> 
>>>>>> Disabling all debugging made me win 200/300 more IOPS. 
>>>>>> 
>>>>>> See my fio template: 
>>>>>> 
>>>>>> [global] 
>>>>>> #logging 
>>>>>> #write_iops_log=write_iops_log 
>>>>>> #write_bw_log=write_bw_log 
>>>>>> #write_lat_log=write_lat_lo 
>>>>>> 
>>>>>> time_based 
>>>>>> runtime=60 
>>>>>> 
>>>>>> ioengine=rbd 
>>>>>> clientname=admin 
>>>>>> pool=test 
>>>>>> rbdname=fio 
>>>>>> invalidate=0 # mandatory 
>>>>>> #rw=randwrite 
>>>>>> rw=write 
>>>>>> bs=4k 
>>>>>> #bs=32m 
>>>>>> size=5G 
>>>>>> group_reporting 
>>>>>> 
>>>>>> [rbd_iodepth32] 
>>>>>> iodepth=32 
>>>>>> direct=1 
>>>>>> 
>>>>>> See my rio output: 
>>>>>> 
>>>>>> rbd_iodepth32: (g=0): rw=write, bs=4K-4K/4K-4K/4K-4K, 
>>>>>> ioengine=rbd, iodepth=32 fio-2.1.11-14-gb74e Starting 1 process 
>>>>>> rbd engine: RBD version: 0.1.8 
>>>>>> Jobs: 1 (f=1): [W(1)] [100.0% done] [0KB/12876KB/0KB /s] 
>>>>>> [0/3219/0 iops] [eta 00m:00s] 
>>>>>> rbd_iodepth32: (groupid=0, jobs=1): err= 0: pid=32116: Thu Aug 28 
>>>>>> 00:28:26 2014 
>>>>>> write: io=771448KB, bw=12855KB/s, iops=3213, runt= 60010msec slat 
>>>>>> (usec): min=42, max=1578, avg=66.50, stdev=16.96 clat (msec): 
>>>>>> min=1, max=28, avg= 9.85, stdev= 1.48 lat (msec): min=1, max=28, 
>>>>>> avg= 9.92, stdev= 1.47 clat percentiles (usec): 
>>>>>> | 1.00th=[ 6368], 5.00th=[ 8256], 10.00th=[ 8640], 20.00th=[ 
>>>>>> | 9152], 30.00th=[ 9408], 40.00th=[ 9664], 50.00th=[ 9792], 
>>>>>> | 60.00th=[10048], 70.00th=[10176], 80.00th=[10560], 
>>>>>> | 90.00th=[10944], 95.00th=[11456], 99.00th=[13120], 
>>>>>> | 99.50th=[16768], 99.90th=[25984], 99.95th=[27008], 
>>>>>> | 99.99th=[28032] 
>>>>>> bw (KB /s): min=11864, max=13808, per=100.00%, avg=12864.36, 
>>>>>> stdev=407.35 lat (msec) : 2=0.03%, 4=0.54%, 10=59.79%, 20=39.24%, 
>>>>>> 50=0.41% cpu : usr=19.15%, sys=4.69%, ctx=326309, majf=0, 
>>>>>> minf=426088 IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=33.9%, 
>>>>>> 32=66.1%, >=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=99.6%, 8=0.4%, 
>>>>>> 16=0.1%, 32=0.1%, 64=0.0%, >=64=0.0% issued : 
>>>>>> total=r=0/w=192862/d=0, short=r=0/w=0/d=0 latency : target=0, 
>>>>>> window=0, percentile=100.00%, depth=32 
>>>>>> 
>>>>>> Run status group 0 (all jobs): 
>>>>>> WRITE: io=771448KB, aggrb=12855KB/s, minb=12855KB/s, 
>>>>>> maxb=12855KB/s, mint=60010msec, maxt=60010msec 
>>>>>> 
>>>>>> Disk stats (read/write): 
>>>>>> dm-1: ios=0/49, merge=0/0, ticks=0/12, in_queue=12, util=0.01%, 
>>>>>> aggrios=0/22, aggrmerge=0/27, aggrticks=0/12, aggrin_queue=12, 
>>>>>> aggrutil=0.01% 
>>>>>> sda: ios=0/22, merge=0/27, ticks=0/12, in_queue=12, util=0.01% 
>>>>>> 
>>>>>> I tried to tweak several parameters like: 
>>>>>> 
>>>>>> filestore_wbthrottle_xfs_ios_start_flusher = 10000 
>>>>>> filestore_wbthrottle_xfs_ios_hard_limit = 10000 
>>>>>> filestore_wbthrottle_btrfs_ios_start_flusher = 10000 
>>>>>> filestore_wbthrottle_btrfs_ios_hard_limit = 10000 filestore queue 
>>>>>> max ops = 2000 
>>>>>> 
>>>>>> But didn't any improvement. 
>>>>>> 
>>>>>> Then I tried other things: 
>>>>>> 
>>>>>> * Increasing the io_depth up to 256 or 512 gave me between 50 to 100 
>>>>>> more IOPS but it's not a realistic workload anymore and not that 
>>>>>> significant. 
>>>>>> * adding another SSD for the journal, still getting 3,2K IOPS 
>>>>>> * I tried with rbd bench and I also got 3K IOPS 
>>>>>> * I ran the test on a client machine and then locally on the 
>>>>>> server, still getting 3,2K IOPS 
>>>>>> * put the journal in memory, still getting 3,2K IOPS 
>>>>>> * with 2 clients running the test in parallel I got a total of 
>>>>>> 3,6K IOPS but I don't seem to be able to go over 
>>>>>> * I tried is to add another OSD to that SSD, so I had 2 OSD and 2 
>>>>>> journals on 1 SSD, got 4,5K IOPS YAY! 
>>>>>> 
>>>>>> Given the results of the last time it seems that something is limiting 
>>>>>> the number of IOPS per OSD process. 
>>>>>> 
>>>>>> Running the test on a client or locally didn't show any difference. 
>>>>>> So it looks to me that there is some contention within Ceph that might 
>>>>>> cause this. 
>>>>>> 
>>>>>> I also ran perf and looked at the output, everything looks decent, but 
>>>>>> someone might want to have a look at it :). 
>>>>>> 
>>>>>> We have been able to reproduce this on 3 distinct platforms with some 
>>>>>> deviations (because of the hardware) but the behaviour is the same. 
>>>>>> Any thoughts will be highly appreciated, only getting 3,2k out of an 29K 
>>>>>> IOPS SSD is a bit frustrating :). 
>>>>>> 
>>>>>> Cheers. 
>>>>>> ---- 
>>>>>> Sébastien Han 
>>>>>> Cloud Architect 
>>>>>> 
>>>>>> "Always give 100%. Unless you're giving blood." 
>>>>>> 
>>>>>> Phone: +33 (0)1 49 70 99 72 
>>>>>> Mail: 
>>>>>> sebastien....@enovance.com 
>>>>>> 
>>>>>> Address : 11 bis, rue Roquépine - 75008 Paris Web : 
>>>>>> www.enovance.com 
>>>>>> - Twitter : @enovance 
>>>>>> 
>>>>>> 
>>>>> Cheers. 
>>>>> ---- 
>>>>> Sébastien Han 
>>>>> Cloud Architect 
>>>>> 
>>>>> "Always give 100%. Unless you're giving blood." 
>>>>> 
>>>>> Phone: +33 (0)1 49 70 99 72 
>>>>> Mail: 
>>>>> sebastien....@enovance.com 
>>>>> 
>>>>> Address : 11 bis, rue Roquépine - 75008 Paris Web : 
>>>>> www.enovance.com 
>>>>> - Twitter : @enovance 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> _______________________________________________ 
>>>>> ceph-users mailing list 
>>>>> 
>>>>> ceph-us...@lists.ceph.comhttp://lists.ceph.com/listinfo.cgi/ceph-u 
>>>>> sers-ceph.com 
>>>> -- 
>>>> Cédric 
>>>> 
>>>> _______________________________________________ 
>>>> ceph-users mailing list 
>>>> ceph-users@lists.ceph.com 
>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com 
>>> Cheers. 
>>> ---- 
>>> Sébastien Han 
>>> Cloud Architect 
>>> 
>>> "Always give 100%. Unless you're giving blood." 
>>> 
>>> Phone: +33 (0)1 49 70 99 72 
>>> Mail: sebastien....@enovance.com 
>>> Address : 11 bis, rue Roquépine - 75008 Paris Web : www.enovance.com 
>>> - Twitter : @enovance 
>>> 
>>> 
>>> _______________________________________________ 
>>> ceph-users mailing list 
>>> ceph-users@lists.ceph.com 
>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com 
>>> _______________________________________________ 
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>>> ceph-users@lists.ceph.com 
>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com 
> 
> -- 
> Cédric 
> 
> _______________________________________________ 
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Cheers. 
---- 
Sébastien Han 
Cloud Architect 

"Always give 100%. Unless you're giving blood." 

Phone: +33 (0)1 49 70 99 72 
Mail: sebastien....@enovance.com 
Address : 11 bis, rue Roquépine - 75008 Paris Web : www.enovance.com - Twitter 
: @enovance 
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