Prometheus Slurm Exporter

Prometheus collector and exporter for metrics extracted from the Slurm resource scheduling system.

Exported Metrics

State of the CPUs

• Allocated: CPUs which have been allocated to a job.
• Idle: CPUs not allocated to a job and thus available for use.
• Other: CPUs which are unavailable for use at the moment.
• Total: total number of CPUs.

• Information extracted from the SLURM sinfo command.
• Slurm CPU Management User and Administrator Guide

State of the GPUs

• Allocated: GPUs which have been allocated to a job.
• Other: GPUs which are unavailable for use at the moment.
• Total: total number of GPUs.
• Utilization: total GPU utiliazation on the cluster.

• Information extracted from the SLURM sinfo and sacct command.
• Slurm GRES scheduling

NOTE: since version 0.19, GPU accounting has to be explicitly enabled adding the -gpus-acct option to the command line otherwise it will not be activated.

Be aware that:

• According to issue #38, users reported that newer version of Slurm provides slightly different output and thus GPUs accounting may not work properly.
• Users who do not have GPUs and/or do not have accounting activated may want to keep GPUs accounting off (see issue #45).

State of the Nodes

• Allocated: nodes which has been allocated to one or more jobs.
• Completing: all jobs associated with these nodes are in the process of being completed.
• Down: nodes which are unavailable for use.
• Drain: with this metric two different states are accounted for:
  • nodes in drained state (marked unavailable for use per system administrator request)
  • nodes in draining state (currently executing jobs but which will not be allocated for new ones).
• Fail: these nodes are expected to fail soon and are unavailable for use per system administrator request.
• Error: nodes which are currently in an error state and not capable of running any jobs.
• Idle: nodes not allocated to any jobs and thus available for use.
• Maint: nodes which are currently marked with the maintenance flag.
• Mixed: nodes which have some of their CPUs ALLOCATED while others are IDLE.
• Resv: these nodes are in an advanced reservation and not generally available.

• Information extracted from the SLURM sinfo command.

Additional info about node usage

Since version 0.18, the following information are also extracted and exported for every node known by Slurm:

• CPUs: how many are allocated, idle, other and in total.
• Memory: allocated and in total.
• Labels: hostname and its Slurm status (e.g. idle, mix, allocated, draining, etc.).

See the related test data to check the format of the information extracted from Slurm.

Status of the Jobs

• PENDING: Jobs awaiting for resource allocation.
• PENDING_DEPENDENCY: Jobs awaiting because of an unexecuted job dependency.
• RUNNING: Jobs currently allocated.
• SUSPENDED: Job has an allocation but execution has been suspended and CPUs have been released for other jobs.
• CANCELLED: Jobs which were explicitly cancelled by the user or system administrator.
• COMPLETING: Jobs which are in the process of being completed.
• COMPLETED: Jobs have terminated all processes on all nodes with an exit code of zero.
• CONFIGURING: Jobs have been allocated resources, but are waiting for them to become ready for use.
• FAILED: Jobs terminated with a non-zero exit code or other failure condition.
• TIMEOUT: Jobs terminated upon reaching their time limit.
• PREEMPTED: Jobs terminated due to preemption.
• NODE_FAIL: Jobs terminated due to failure of one or more allocated nodes.

• Information extracted from the SLURM squeue command.

State of the Partitions

• Running/suspended Jobs per partitions, divided between Slurm accounts and users.
• CPUs total/allocated/idle per partition plus used CPU per user ID.

Jobs information per Account and User

The following information about jobs are also extracted via squeue:

• Running/Pending/Suspended jobs per SLURM Account.
• Running/Pending/Suspended jobs per SLURM User.

Scheduler Information

• Server Thread count: The number of current active slurmctld threads.
• Queue size: The length of the scheduler queue.
• DBD Agent queue size: The length of the message queue for SlurmDBD.
• Last cycle: Time in microseconds for last scheduling cycle.
• Mean cycle: Mean of scheduling cycles since last reset.
• Cycles per minute: Counter of scheduling executions per minute.
• (Backfill) Last cycle: Time in microseconds of last backfilling cycle.
• (Backfill) Mean cycle: Mean of backfilling scheduling cycles in microseconds since last reset.
• (Backfill) Depth mean: Mean of processed jobs during backfilling scheduling cycles since last reset.
• (Backfill) Total Backfilled Jobs (since last slurm start): number of jobs started thanks to backfilling since last Slurm start.
• (Backfill) Total Backfilled Jobs (since last stats cycle start): number of jobs started thanks to backfilling since last time stats where reset.
• (Backfill) Total backfilled heterogeneous Job components: number of heterogeneous job components started thanks to backfilling since last Slurm start.

• Information extracted from the SLURM sdiag command.

DBD Agent queue size: it is particularly important to keep track of it, since an increasing number of messages counted with this parameter almost always indicates three issues:

• the SlurmDBD daemon is down;
• the database is either down or unreachable;
• the status of the Slurm accounting DB may be inconsistent (e.g. sreport missing data, weird utilization of the cluster, etc.).

Share Information

Collect share statistics for every Slurm account. Refer to the manpage of the sshare command to get more information.

Installation

• Read DEVELOPMENT.md in order to build the Prometheus Slurm Exporter. After a successful build copy the executable bin/prometheus-slurm-exporter to a node with access to the Slurm command-line interface.

• A Systemd Unit file to run the executable as service is available in lib/systemd/prometheus-slurm-exporter.service.

• (optional) Distribute the exporter as a Snap package: consult the following document. NOTE: this method requires the use of Snap, which is built by Canonical.

Prometheus Configuration for the SLURM exporter

It is strongly advisable to configure the Prometheus server with the following parameters:

scrape_configs:

#
# SLURM resource manager:
#
  - job_name: 'my_slurm_exporter'

    scrape_interval:  30s

    scrape_timeout:   30s

    static_configs:
      - targets: ['slurm_host.fqdn:8080']

• scrape_interval: a 30 seconds interval will avoid possible 'overloading' on the SLURM master due to frequent calls of sdiag/squeue/sinfo commands through the exporter.
• scrape_timeout: on a busy SLURM master a too short scraping timeout will abort the communication from the Prometheus server toward the exporter, thus generating a context_deadline_exceeded error.

The previous configuration file can be immediately used with a fresh installation of Prometheus. At the same time, we highly recommend to include at least the global section into the configuration. Official documentation about configuring Prometheus is available here.

NOTE: the Prometheus server is using YAML as format for its configuration file, thus indentation is really important. Before reloading the Prometheus server it would be better to check the syntax:

$~ promtool check-config prometheus.yml

Checking prometheus.yml
  SUCCESS: 1 rule files found
[...]

Grafana Dashboard

A dashboard is available in order to visualize the exported metrics through Grafana:

License

Copyright 2017-2020 Victor Penso, Matteo Dessalvi

This is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.