The symptom is that SLURM schedules lower priority jobs to run when higher priority, dependent jobs have their dependencies satisfied.  This happens because dependent jobs still have a priority of 1 when the job queue is sorted in the schedule() function.  The proposed fix forces jobs to have their priority updated when their dependencies are satisfied.

Here is the way to reproduce it :
[root@cuzco27 georgioy]# salloc -n64 -N4 --exclusive
salloc: Granted job allocation 8
[root@cuzco27 georgioy]#srun -r 0 -n 30 -N 2 sleep 300&
[root@cuzco27 georgioy]#srun -r 1 -n 40 -N 3 sleep 300&
[root@cuzco27 georgioy]# srun: error: slurm_receive_msg: Zero Bytes were transmitted or received
srun: error: Unable to create job step: Zero Bytes were transmitted or received

batch jobs.

Previously the code would come up with how much memory a PE should have
instead of the memory a node should have.

Fix sched/wiki2 to support job account name, gres, partition name, wckey,
or working directory that contains "#" (a job record separator). Without
this patch, the parsing will probably stop once reaching the "#".

and time limit where it was previously set by an admin.

slurmdbd accounting and running large amounts of jobs (>50 sec).  Job
information could be corrupted before it had a chance to reach the DBD.

Add support for new SchedulerParameters of max_depend_depth defining the
maximum number of jobs to test for circular dependencies (i.e. job A waits
for job B to start and job B waits for job A to start). Default value is
10 jobs.

The problem was conflicting logic in the select/cons_res plugin. Some of the code was trying to get the job the maximum node count in the range while other logic was trying to minimize spreading out of the job across multiple switches. As you note, this problem only happens when a range of node counts is specified and the select/cons_res plugin and the topology/tree plugin and even then it is not easy to reproduce (you included all of the details below).

Quoting Martin.Perry@Bull.com:

> Certain combinations of topology configuration and srun -N option produce
> spurious job rejection with "Requested node configuration is not
> available" with select/cons_res. The following example illustrates the
> problem.
>
> [sulu] (slurm) etc> cat slurm.conf
> ...
> TopologyPlugin=topology/tree
> SelectType=select/cons_res
> SelectTypeParameters=CR_Core
> ...
>
> [sulu] (slurm) etc> cat topology.conf
> SwitchName=s1 Nodes=xna[13-26]
> SwitchName=s2 Nodes=xna[41-45]
> SwitchName=s3 Switches=s[1-2]
>
> [sulu] (slurm) etc> sinfo
> PARTITION AVAIL  TIMELIMIT  NODES  STATE NODELIST
> ...
> jkob         up   infinite      4   idle xna[14,19-20,41]
> ...
>
> [sulu] (slurm) etc> srun -N 2-4 -n 4 -p jkob hostname
> srun: Force Terminated job 79
> srun: error: Unable to allocate resources: Requested node configuration is
> not available
>
> The problem does not occur with select/linear, or topology/none, or if -N
> is omitted, or for certain other values for -N (for example, -N 4-4 and -N
> 2-3 work ok). The problem seems to be in function _eval_nodes_topo in
> src/plugins/select/cons_res/job_test.c. The srun man page states that when
> -N is used, "the job will be allocated as many nodes as possible within
> the range specified and without delaying the initiation of the job."
> Consistent with this description, the requested number of nodes in the
> above example is 4 (req_nodes=4).  However, the code that selects the
> best-fit topology switches appears to make the selection based on the
> minimum required number of nodes (min_nodes=2). It therefore selects
> switch s1.  s1 has only 3 nodes from partition jkob. Since this is fewer
> than req_nodes the job is rejected with the "node configuration" error.
>
> I'm not sure where the code is going wrong.  It could be in the
> calculation of the number of needed nodes in function _enough_nodes.  Or
> it could be in the code that initializes/updates req_nodes or rem_nodes. I
> don't feel confident that I understand the logic well enough to propose a
> fix without introducing a regression.
>
> Regards,
> Martin

When the optional max_time is not specified for --switches=count, the site
max (SchedulerParameters=max_switch_wait=seconds) is used for the job.
Based on patch from Rod Schultz.

Patch by Bill Brophy, Bull.

Patch by Don Lipari, LLNL.
https://github.com/chaos/slurm/commit/4de11bf0a8cd18207a60e7d3e1fa7a6fde0da431

CRAY: Fix support for configuration with SlurmdTimeout=0 (never mark
node that is DOWN in ALPS as DOWN in SLURM).

Improve support for overlapping advanced reservations.
Patch from Bill Brophy, Bull.

already pinged it on startup the unresponding flag would be removed from
the frontend node.

mark front end node down.

Cray - For srun wrapper when creating a job allocation, set the default job
name to the executable file's name. Ignore leading directory names in the path.

permit the srun and salloc commands to be executed in the background
on Cray systems

Add new job state reason of "FrontEndDown" which applies only to Cray and
IBM BlueGene systems.

the queue when trying to place a larger than midplane job.

In cray/srun wrapper, only include aprun "-q" option when srun "--quiet"
option is used.