On 18/07/2020 00:05, Daniel Mezentsev wrote:
Hi All,
I started a small project related to metrics collection and processing, Ceph was chosen as a storage backend. Decided to use rados directly, to avoid any additional layers. I got a very simple client - it works fine, but performance is very low. Can't get more than 30-35MBsec. Rados bench shows 200MBsec for my test pool. Should be mentioned about the client - I'm using sbcl (yep lisp). Call to rados API is just cffi call.
Did try in async mode. Wow ! Saturated network bandwidth for large objects (4Mb and bigger), for small objects - saturated OSD IOPS ~2.4KIOPS for 8 SAS disks, so ~300 IOPS per disk - that sounds pretty reasonable. Bottom line - issue not with the lisp client - im getting close to C performance, difference is sync vs async IO.
Why it's so big - sync operations are approx 2-3 times slower then async . Daniel Mezentsev, founder (+1) 604 313 8592. Soleks Data Group. Shaping the clouds. _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
What do you get in your rados benchmark result if you add -t 1 to indicate 1 thread/queue depth to make it similar to your simple client, the default is 16. You should also either use 4M block size in your client or adjust the rados bench block size with -b /Maged