[slurm-users] Fwd: Slurm MySQL database configuration

[Tina Friedrich]

Hi Peter,

is this an actual NFS server, or something exporting NFS (like a NetApp).

This might be a silly question but - if it's an actual server, could you 
run the slurmdb server on the NFS server? There would then be no need 
for any clustered DB service or anything; it would simply make the 
slurmdbd accessible as and when your NFS server is up.

If that's not an option - yes, you would need to configure some sort of 
failover cluster for it, including the mounting of the database.

Have you got something like a VMWare about? You could run the slurmdbd 
server as a (single) VM and handle the failover on the hypervisor level.

Tina

On 23/07/2020 16:53, Peter Mayes wrote:
> Hi Folks,
>
> Thanks for responses.
>
> I probably didn't make my initial point totally clear, so following up
> with clarification.
>
> The NFS server is considered to be sufficiently highly available
> ("Designed for 99.9999% availability with redundant hot-swap components,
> including controllers and I/O modules, power supplies, cooling modules")
> that we had assumed this was sufficient for the Slurm database, without
> additional Database HA features, like Galera, DRBD, etc etc
>
> So the idea was to have the two Slurm server nodes, each running
> slurmctld, slurmdbd, mariadb, but the two mariadb instances would be
> referencing the same physical database, with only one of the Slurm nodes
> doing any database updates at any one time.
>
> Is this a possible configuration? If so, how to get both the mariadb
> instances to be running simultaneously (with one idle) accessing the
> same database files.
>
> It seems silly to have two database instances on the same NFS server
> replicating with something like Galera.
>
> Thanks again
> --
> Peter
>
> -------
> Hi,
>
> My first post to the list, so apologies if this is a FAQ,
>
> My configuration has two nodes allocated for Slurm masters, with a
> highly-available NFS server mounting a filesystem across the two nodes.
>
> I need advice on the best configuration.
>
> I naively thought of having a single MariaDB database located in the NFS
> server, with slurmctld, slurmdbd and mariadb running on both slurm
> nodes, with only one slurmdbd/mariadb actively touching the database at
> any one time.
>
> slurm.conf
> ----------
> SlurmctldHost=slurm1(a.b.c.1)
> SlurmctldHost=slurm2(a.b.c.2)
>
> AccountingStorageHost=slurm1
> AccountingStorageBackupHost=slurm2
>
> slurmdbd.conf
> -------------
>
> DbdHost=slurm1
> DbdBackupHost=slurm2
>
> StorageHost=localhost
>
> But MariaDB doesn't seem to like (possibly understandably) two mysql
> daemons accessing a single database instance from two servers.
>
> What would be the best way to configure this setup?
>
> Thanks in advance
>
> -- Peter