[slurm-users] Slurm account names limitation: must be unique in the first 20 characters

[Jacob Chappell]

Thanks, Jeffrey. It looks like this limit has been changed to 42 on the
master branch of Slurm, so I suppose a future version of Slurm (19?) will
fix this.

__________________________________________________
*Jacob D. Chappell, CSM*
*Research Computing Associate*
Research Computing | Research Computing Infrastructure
Information Technology Services | University of Kentucky
jacob.chappell at uky.edu


On Mon, Dec 10, 2018 at 1:34 PM Jeffrey Frey <frey at udel.edu> wrote:

> For MySQL to use a text column as a primary key, it requires a limit on
> how many bytes are significant.  Just check through
> src/plugins/accounting_storage/mysql/accounting_storage_mysql.c and you'll
> see lots of primary keys with "(20)" indexing lengths specified.
>
>
> With an extant database you may be able to alter all respective tables'
> primary key definitions.  Whether or not MySQL will rebuild the primary key
> index for you, I can't say.  My guess is that a safer solution would be to
> export the database, shutdown Slurm/Slurmdbd, alter the primary key
> definitions in the export, then import into a fresh database; point
> Slurmdbd at your fresh database and bring it all back online.  Obviously
> you could have issues in the future when/if the database schema changes and
> Slurm tries to auto-upgrade your extant database.
>
>
>
>
>
> > On Dec 10, 2018, at 11:33 AM, Jacob Chappell <jacob.chappell at uky.edu>
> wrote:
> >
> > Hi all,
> >
> > We've come across an issue recently with Slurm account names. Our center
> uses fairly long Slurm account names, as they record various important
> pieces of information about the account such as the user's unique id,
> department, project name, etc. Consequently, our account naming structure
> is such that many accounts share a pretty lengthy common prefix. We've
> discovered that if two account names share a prefix of more than 20
> characters, Slurm will error out and not add the account. We think this has
> to do with the sub_part for the name index set on the acct_table table (see
> below):
> >
> > MariaDB [slurm_accounting]> show index from acct_table\G;
> > *************************** 1. row ***************************
> >         Table: acct_table
> >    Non_unique: 0
> >      Key_name: PRIMARY
> >  Seq_in_index: 1
> >   Column_name: name
> >     Collation: A
> >   Cardinality: 14
> >      Sub_part: 20
> >        Packed: NULL
> >          Null:
> >    Index_type: BTREE
> >       Comment:
> > Index_comment:
> > 1 row in set (0.00 sec)
> >
> > Can this be changed? Changing our account names to not share a common
> prefix would be difficult and cause problems with a lot of other software
> we use that is site-specific. We'd rather just remove the sub_part
> (accepting the performance implications).
> >
> > Thanks,
> > __________________________________________________
> > Jacob D. Chappell, CSM
> > Research Computing Associate
> > Research Computing | Research Computing Infrastructure
> > Information Technology Services | University of Kentucky
> > jacob.chappell at uky.edu
>
>
> ::::::::::::::::::::::::::::::::::::::::::::::::::::::
> Jeffrey T. Frey, Ph.D.
> Systems Programmer V / HPC Management
> Network & Systems Services / College of Engineering
> University of Delaware, Newark DE  19716
> Office: (302) 831-6034  Mobile: (302) 419-4976
> ::::::::::::::::::::::::::::::::::::::::::::::::::::::
>
>
>
>
>
>
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