topology.yaml(5)

NAME
topology.yaml - Slurm configuration file for the topology plugins

DESCRIPTION

topology.yaml is a YAML-formatted configuration file that defines multiple network topologies for optimizing job resource allocation in Slurm. The file must be located in the same directory as slurm.conf. Any text following a "#" in this file is treated as a comment through the end of that line.

Additional details are available in topology.conf(5) and in the Topology Guide: <https://slurm.schedmd.com/topology.html>

NOTE: Slurm will first check for topology.yaml. If this file exists, topology.conf will be ignored.

PARAMETERS

Each topology contains the following attributes:

topology
    Unique name of the topology, will be used to identify it on partition configurations. Must be the first attribute.

cluster_default
    The first topology defined with cluster_default: true will be used for partitions without an explicitly specified topology and cluster-wide operations not tied to a partition (e.g., slurmctld-to-slurmd communication). Defaults to false.

Each topology must also define exactly one of the following topology types:

    block
        This topology will use the topology/block plugin. Must contain additional fields, see below.

    flat
        If set to true, this topology will use the topology/flat plugin, which is the default if no TopologyPlugin or topology.yaml is specified.

    tree
        This topology will use the topology/tree plugin. Must contain additional fields, see below.

  Block definitions

Each block topology contains the following attributes:

block_sizes
    List of the planning base block size, alongside any higher-level block sizes that would be enforced. Successive BlockSizes must be a power of two larger than the prior values.

blocks
    List of blocks available in this topology. Each block contains the following attributes:

    block
        The name of a block. This name is internal to Slurm and arbitrary. Each block should have a unique name. This field must be specified.

    nodes
        Child nodes of the named block.

  Tree definitions

Each tree topology contains the following attribute:

switches
    List of switches available in this topology. Each switch contains the following attributes:

    switch
        The name of a switch. This name is internal to Slurm and arbitrary. Each switch should have a unique name. This field must be specified and cannot be longer than 64 characters.

    children
        Child switches of the named switch.

    nodes
        Child nodes of the named leaf switch.

EXAMPLE
---
- topology: topo1
  cluster_default: true
  tree:
    switches:
      - switch: sw_root
        children: s[1-2]
      - switch: s1
        nodes: node[01-02]
      - switch: s2
        nodes: node[03-04]
- topology: topo2
  cluster_default: false
  block:
    block_sizes:
      - 4
      - 16
    blocks:
      - block: b1
        nodes: node[01-04]
      - block: b2
        nodes: node[05-08]
      - block: b3
        nodes: node[09-12]
      - block: b4
        nodes: node[13-16]
- topology: topo3
  cluster_default: false
  flat: true

COPYING
Copyright (C) 2025 SchedMD LLC.

This file is part of Slurm, a resource management program. For details, see <https://slurm.schedmd.com/>.

Slurm 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 2 of the License, or (at your option) any later version.

Slurm 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.

SEE ALSO

slurm.conf(5), topology.conf(5)