[slurm-users] Slurm Upgrade

[Jason Simms]

Hello all,

I am going to reveal the degree of my inexperience here, but am I perhaps
the only one who thinks that Slurm's upgrade procedure is too complex? Or,
at least maybe not explained in enough detail?

I'm running a CentOS 8 cluster, and to me, I should be able simply to
update the Slurm package and any of its dependencies, and that's it. When I
looked at the notes from the recent Slurm Users' Group meeting, however, I
see that while that mode is technically supported, it is not recommended,
and instead one should always rebuild from source. Really?

So, ok, regardless whether that's the case, the upgrade notes linked to in
the prior post don't, in my opinion, go into enough detail. It tells you
broadly what to do, but not necessarily how to do it. I'd welcome example
commands for each step (understanding that changes might be needed to
account for local configurations). There are no examples in that section,
for example, addressing recompiling from source.

Now, I suspect a chorus of "if you don't understand it well enough, you
shouldn't be managing it." OK. Perhaps that's fair enough. But I came into
this role via a non-traditional route and am constantly trying to improve
my admin skills, and I may not have the complete mastery of all aspects
quite yet. But I would also say that documentation should be clear and
complete, and not written solely for experts. To be honest, I've had to go
to lots of documentation external to SchedMD to see good examples of
actually working with Slurm, or even ask the helpful people on this group.
And I firmly believe that if there is a packaged version of your software -
as there is for Slurm - that should be the default, fully-working way to
upgrade.

Warmest regards,
Jason

On Mon, Nov 2, 2020 at 9:28 AM Paul Edmon <pedmon at cfa.harvard.edu> wrote:

> In general  I would follow this:
>
> https://slurm.schedmd.com/quickstart_admin.html#upgrade
>
> Namely:
>
> Almost every new major release of Slurm (e.g. 19.05.x to 20.02.x) involves
> changes to the state files with new data structures, new options, etc.
> Slurm permits upgrades to a new major release from the past two major
> releases, which happen every nine months (e.g. 18.08.x or 19.05.x to
> 20.02.x) without loss of jobs or other state information. State information
> from older versions will not be recognized and will be discarded, resulting
> in loss of all running and pending jobs. State files are *not* recognized
> when downgrading (e.g. from 19.05.x to 18.08.x) and will be discarded,
> resulting in loss of all running and pending jobs. For this reason,
> creating backup copies of state files (as described below) can be of value.
> Therefore when upgrading Slurm (more precisely, the slurmctld daemon),
> saving the *StateSaveLocation* (as defined in *slurm.conf*) directory
> contents with all state information is recommended. If you need to
> downgrade, restoring that directory's contents will let you recover the
> jobs. Jobs submitted under the new version will not be in those state
> files, but it can let you recover most jobs. An exception to this is that
> jobs may be lost when installing new pre-release versions (e.g.
> 20.02.0-pre1 to 20.02.0-pre2). Developers will try to note these cases in
> the NEWS file. Contents of major releases are also described in the
> RELEASE_NOTES file.
>
> So I wouldn't go directly to 20.x, instead I would go from 17.x to 19.x
> and then to 20.x
>
> -Paul Edmon-
> On 11/2/2020 8:55 AM, Fulcomer, Samuel wrote:
>
> We're doing something similar. We're continuing to run production on 17.x
> and have set up a new server/cluster  running 20.x for testing and MPI app
> rebuilds.
>
> Our plan had been to add recently purchased nodes to the new cluster, and
> at some point turn off submission on the old cluster and switch everyone
> to  submission on the new cluster (new login/submission hosts). That way
> previously submitted MPI apps would continue to run properly. As the old
> cluster partitions started to clear out we'd mark ranges of nodes to drain
> and move them to the new cluster.
>
> We've since decided to wait until January, when we've scheduled some
> downtime. The process will remain the same wrt moving nodes from the old
> cluster to the new, _except_ that everything will be drained, so we can
> move big blocks of nodes and avoid slurm.conf Partition line ugliness.
>
> We're starting with a fresh database to get rid of the bug
> induced corruption that prevents GPUs from being fenced with cgroups.
>
> regards,
> s
>
> On Mon, Nov 2, 2020 at 8:28 AM navin srivastava <navin.altair at gmail.com>
> wrote:
>
>> Dear All,
>>
>> Currently we are running slurm version 17.11.x and wanted to move to 20.x.
>>
>> We are building the New server with Slurm 20.2 version and planning to
>> upgrade the client nodes from 17.x to 20.x.
>>
>> wanted to check if we can upgrade the Client from 17.x to 20.x directly
>> or we need to go through 17.x to 18.x and 19.x then 20.x
>>
>> Regards
>> Navin.
>>
>>
>>
>>

-- 
*Jason L. Simms, Ph.D., M.P.H.*
Manager of Research and High-Performance Computing
XSEDE Campus Champion
Lafayette College
Information Technology Services
710 Sullivan Rd | Easton, PA 18042
Office: 112 Skillman Library
p: (610) 330-5632
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