[Gluster-users] Poor performance on a server-class system vs. desktop

[Gionatan Danti]

Il 2020-11-27 06:53 Dmitry Antipov ha scritto:
> Thanks, it seems you're right. Running local replica 3 volume on 3x1Gb
> ramdisks, I'm seeing:
> 
> top - 08:44:35 up 1 day, 11:51,  1 user,  load average: 2.34, 1.94, 
> 1.00
> Tasks: 237 total,   2 running, 235 sleeping,   0 stopped,   0 zombie
> %Cpu(s): 38.7 us, 29.4 sy,  0.0 ni, 23.6 id,  0.0 wa,  0.4 hi,  7.9 si, 
>  0.0 st
> MiB Mem :  15889.8 total,   1085.7 free,   1986.3 used,  12817.8 
> buff/cache
> MiB Swap:      0.0 total,      0.0 free,      0.0 used.  12307.3 avail 
> Mem
> 
>   PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ 
> COMMAND
> 63651 root      20   0  664124  41676   9600 R 166.7   0.3   0:24.20 
> fio
> 63282 root      20   0 1235336  21484   8768 S 120.4   0.1   2:43.73 
> glusterfsd
> 63298 root      20   0 1235368  20512   8856 S 120.0   0.1   2:42.43 
> glusterfsd
> 63314 root      20   0 1236392  21396   8684 S 119.8   0.1   2:41.94 
> glusterfsd
> 
> So, 32-core server-class system with a lot of RAM can't perform much
> faster for an
> individual I/O client - it just scales better if there are a lot of
> clients, right?

Yes, it should scale with additional clients and bricks.

As a side note, this high-cpu, (relatively) low-perf result was the 
reason why I abandoned the idea to use a 3-way Gluster as backing store 
for hyperconverged KVM setup (with VMs running on the same Gluster 
host): while adequate for "normal" VMs, it would not fit the bill for 
high performance guest.

Increasing the number of bricks/clients would ameliorate the situation, 
but we are suddenly in the "rack full of gluster server" setup (which is 
not compatible with my customers requests).

If anyone has some suggestions, I am all ears!
Regards.

-- 
Danti Gionatan
Supporto Tecnico
Assyoma S.r.l. - www.assyoma.it
email: g.danti at assyoma.it - info at assyoma.it
GPG public key ID: FF5F32A8