On 3/4/19 1:27 PM, Paul Edmon wrote:
That should work.
It did work as expected :-)
The upgrade though will have to wait until the dbd is actually on a different
server.
Yes, that's the whole point of first migrating slurmdbd to a different
server! Upgrading the Slurm RPMs on the slurmdbd server from 17.11 to
18.08 consequently doesn't impact the running slurmctld. I did so this
morning without any troubles at all.
We run the ctld and dbd on the same machine here for the sake of performance.
Before the rpm reorg we used to upgrade only the dbd first and then the ctld
but with the reorg I'm taking a downtime for the dbd upgrade. That's not too
bad though as we pause all our jobs out of paranoia for upgrades.
My strategy is to avoid any downtime at all = lost productivity.
/Ole
On 3/1/19 8:10 AM, Ole Holm Nielsen wrote:
We're one of the many Slurm sites which run the slurmdbd database
daemon on the same server as the slurmctld daemon. This works without
problems at our site given our modest load, however, SchedMD
recommends to run the daemons on separate servers.
Contemplating how to upgrade our cluster from Slurm 17.11 to 18.08,
I've come to appreciate the advantage of running the daemons on
separate servers: One can upgrade slurmdbd to 18.08 while keeping
slurmctld at 17.11 (for a while at least). This enables us to upgrade
to 18.08 in the recommended order without any interruption to our
running jobs and without any cluster downtime.
I've been collecting various pieces of information about Slurm
upgrades and I've come up with a tested procedure for migrating the
slurmdbd service (on a CentOS/RHEL 7 system) to a new server:
https://wiki.fysik.dtu.dk/niflheim/Slurm_database#migrate-the-slurmdbd-service-to-another-server
The basic idea is that slurmctld continues happily while slurmdbd is
down, so you can migrate the MySQL database and slurmdbd behind the
scenes. When the new slurmdbd server is up and running, you
reconfigure slurm.conf on the cluster.
Upgrading slurmctld and slurmd is another topic, and this is discussed
in my Wiki page
https://wiki.fysik.dtu.dk/niflheim/Slurm_installation#upgrading-slurm.
I'd appreciate comments and suggestions about my procedure.
