Gluster users - Jul 2020 - Replica scenario in low speed link

Hi!

I have a strange request. I don't know if some gluster settings could 
help me.

There are two buildings linked using a wifi bridge.
The main building host the data centre.? In the other building there are 
an office
that need to use a file server with high speed, so the wifi link is not 
optimal.

My fantasy suggest me to have a server in this office running samba and 
gluster.
Gluster have to read/write immediately from the local storage and 
leisurely replicate on remote storage (maybe a replica 3,
or replica 2 + arbiter with locally one replica and the arbiter).
In case of local storage/machine fault the system have to read/write 
using the remote brick over "slow" link
and restart to use local storage when it return to be available and synced.

Samba could be running only on this office or have two instances, in HA 
cluster, one in this office and
other in the main building.

Anyone have any suggestions or have they had a similar need?

Thanks, bye.

Il 2020-07-21 14:45 Stefano Danzi ha scritto:
> Hi!
> 
> I have a strange request. I don't know if some gluster settings could 
> help me.
> 
> There are two buildings linked using a wifi bridge.
> The main building host the data centre.? In the other building there
> are an office
> that need to use a file server with high speed, so the wifi link is not 
> optimal.
> 
> My fantasy suggest me to have a server in this office running samba and 
> gluster.
> Gluster have to read/write immediately from the local storage and
> leisurely replicate on remote storage (maybe a replica 3,
> or replica 2 + arbiter with locally one replica and the arbiter).
> In case of local storage/machine fault the system have to read/write
> using the remote brick over "slow" link
> and restart to use local storage when it return to be available and 
> synced.
> 
> Samba could be running only on this office or have two instances, in
> HA cluster, one in this office and
> other in the main building.
> 
> Anyone have any suggestions or have they had a similar need?
> 
> Thanks, bye.
Hi, from what I remember, Gluster (and especially the AFR module) is not 
well suited for high latency, low bandwidth scenario: the risk of split 
brain and link congestion is simply too high.

Full disclaimer: I tried a similar setup in the Gluster 3.3.x days, and 
it did not work well. But this was many years ago, maybe other can prove 
me wrong or give some other advice.

Regards.

-- 
Danti Gionatan
Supporto Tecnico
Assyoma S.r.l. - www.assyoma.it
email: g.danti at assyoma.it - info at assyoma.it
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