I don't disagree, but I agree with Sage that testing different overlay
values is useful as well. I will have results to post later this
morning. At some point soon I'll move on to testing how rocksdb WAL on
SSD and/or rocksdb entirely on SSD helps. There's definitely some
interesting trade-offs here.
Mark
On 04/10/2015 01:11 AM, Duan, Jiangang wrote:
IMHO, the newstore performance depends so much on KV store performance due to the WAL - so pick up the right KV or tune it will be the 1st step to do.
-jiangang
-----Original Message-----
From: ceph-devel-owner@xxxxxxxxxxxxxxx [mailto:ceph-devel-owner@xxxxxxxxxxxxxxx] On Behalf Of Mark Nelson
Sent: Friday, April 10, 2015 1:01 AM
To: Sage Weil
Cc: ceph-devel
Subject: Re: Initial newstore vs filestore results
On 04/08/2015 10:19 PM, Mark Nelson wrote:
On 04/07/2015 09:58 PM, Sage Weil wrote:
What would be very interesting would be to see the 4KB performance
with the defaults (newstore overlay max = 32) vs overlays disabled
(newstore overlay max = 0) and see if/how much it is helping.
And here we go. 1 OSD, 1X replication. 16GB RBD volume.
4MB write read randw randr
default overlay 36.13 106.61 34.49 92.69
no overlay 36.29 105.61 34.49 93.55
128KB write read randw randr
default overlay 1.71 97.90 1.65 25.79
no overlay 1.72 97.80 1.66 25.78
4KB write read randw randr
default overlay 0.40 61.88 1.29 1.11
no overlay 0.05 61.26 0.05 1.10
Update this morning. Also ran filestore tests for comparison. Next we'll look at how tweaking the overlay for different IO sizes affects things. IE the overlay threshold is 64k right now and it appears that 128K write IOs for instance are quite a bit worse with newstore currently than with filestore. Sage also just committed changes that will allow overlay writes during append/create which may help improve small IO write performance as well in some cases.
4MB write read randw randr
default overlay 36.13 106.61 34.49 92.69
no overlay 36.29 105.61 34.49 93.55
filestore 36.17 84.59 34.11 79.85
128KB write read randw randr
default overlay 1.71 97.90 1.65 25.79
no overlay 1.72 97.80 1.66 25.78
filestore 27.15 79.91 8.77 19.00
4KB write read randw randr
default overlay 0.40 61.88 1.29 1.11
no overlay 0.05 61.26 0.05 1.10
filestore 4.14 56.30 0.42 0.76
Seekwatcher movies and graphs available here:
http://nhm.ceph.com/newstore/20150408/
Note for instance the very interesting blktrace patterns for 4K random writes on the OSD in each case:
http://nhm.ceph.com/newstore/20150408/filestore/RBD_00004096_randwrite.png
http://nhm.ceph.com/newstore/20150408/default_overlay/RBD_00004096_randwrite.png
http://nhm.ceph.com/newstore/20150408/no_overlay/RBD_00004096_randwrite.png
Mark
--
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
--
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
