Hi Wido,
first of all please note that bitmap allocator implementation for
master/Nautilus is absolutely different from the one for Mimic/Luminous.
It was completely rewritten.
And I recommend to refrain from using legacy bitmap allocator from
Mimic/Luminous.
The rationale behind making bitmap allocator default in master is that
new one provides better performance and memory usage predictability than
stupid one. With IMO shows pretty good stability for now. Hence we are
trying to run (and hence test) it as much as possible before the
Nautilus release.
Speaking of known bugs for this new allocator I recall the only one
which isn't reproducible at the moment: http://tracker.ceph.com/issues/27222
Could you please advise if you know(suspect) any other issues with it?
Thanks,
Igor
On 10/11/2018 2:52 AM, Wido den Hollander wrote:
Hi,
I was wondering how stable useful the Bitmap allocator is vs the Stupid
allocator with BlueStore under Luminous.
In the master branch the Bitmap one is now the default, but why?
Searching for this I couldn't find a proper reason.
The reason I'm asking is that I'm seeing some issues with BlueStore OSDs
running into BlueFS allocation issues when they are filling up.
(WAL+DB+DATA on same SSD).
So one of the things I wanted to try is to switch to Bitmap, but I'd
like to check the stability and reasoning behind it first.
Thanks,
Wido
