[Gluster-users] Graceful gluster server retire/poweroff

[Ravishankar N]

On 16/07/19 3:16 PM, Gionatan Danti wrote:
> Hi list,
> I have a replica 3 test cluster and I have a question about how 
> clients behave to an host shutdown.
>
> If I suddenly switch off one of the gluster server, the connected 
> clients see a ~42s stall in I/O: this is expected, as it is the 
> default client timeout.
>
> However, it is possible to *gracefully* shutdown a running gluster 
> server, *without* impacting a running client? Ie: putting the affected 
> server in a "maintenance mode" of sort.

Yes, if you simply pkill the gluster brick processes of the node before 
switching it off, you won't observe the hang on the clients because they 
will receive the disconnect notification immediately. But before that, 
you would need to check if there are no pending heals etc. You can use 
the script [1] which does all these checks in the graceful mode.

HTH,
Ravi

[1] 
https://github.com/gluster/glusterfs/blob/master/extras/stop-all-gluster-processes.sh

>
> Thanks.
>