Mark, Are you trying with multiple physical clients and with increased OSD shards? Simple should go way more with the similar config for 4K RR based on the result we were getting earlier unless your cpu is getting saturated at the OSD nodes. Thanks & Regards Somnath -----Original Message----- From: ceph-devel-owner@xxxxxxxxxxxxxxx [mailto:ceph-devel-owner@xxxxxxxxxxxxxxx] On Behalf Of Mark Nelson Sent: Wednesday, September 21, 2016 11:50 AM To: ceph-devel Subject: async messenger random read performance on NVMe Recently in master we made async messenger default. After doing a bunch of bisection, it turns out that this caused a fairly dramatic decrease in bluestore random read performance. This is on a cluster with fairly fast NVMe cards, 16 OSDs across 4 OSD hosts. There are 8 fio client processes with 32 concurrent threads each. Ceph master using bluestore Parameters tweaked: ms_async_send_inline ms_async_op_threads ms_async_max_op_threads simple: 168K IOPS send_inline: true async 3/5 threads: 111K IOPS async 4/8 threads: 125K IOPS async 8/16 threads: 128K IOPS async 16/32 threads: 128K IOPS async 24/48 threads: 128K IOPS async 25/50 threads: segfault async 26/52 threads: segfault async 32/64 threads: segfault send_inline: false async 3/5 threads: 153K IOPS async 4/8 threads: 153K IOPS async 8/16 threads: 152K IOPS So definitely setting send_inline to false helps pretty dramatically, though we're still a little slower for small random reads than simple messenger. Haomai, regarding the segfaults, I took a quick look with gdb at the core file but didn't see anything immediately obvious. It might be worth seeing if you can reproduce. On the performance front, I'll try to see if I can see anything obvious in perf. 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 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. If you have received this communication in error, please notify the sender by telephone or e-mail (as shown above) immediately and destroy any and all copies of this message in your possession (whether hard copies or electronically stored copies). ��.n��������+%������w��{.n����z��u���ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
