i am sending this mail for further discussion on our recent perf tests on crimson.

Chunmei also performed performance tests testing classic osd + memstore and crimson osd + cyanstore using "rados bench" and fio. where 

- only a single async_op threads and a single core is designated to classic-osd,

- two rados bench instances were used when testing with "rados bench".

- two jobs are used when testing with fio

- server is not co-located with client.

- single osd instance.

see 

- https://gist.github.com/liu-chunmei/4fd88fd0ff56d6849439a2df329aa80e

- https://gist.github.com/liu-chunmei/f696b9c4f31b123fb223cdd47f13c8ea

respectively.

her findings are

- in the rados bench tests, crimson performs better than classic osd in general.

- in the fio tests, the performance of crimson is almost on par with that of classic osd. the cycles-per-op of crimson is significantly lower than that of classic osd.

but in last standup, she mentioned that her impression was that the alien store does not benefit from adding more threads than 2. this does not match with your findings recently.

thoughts?

cheers,