To match your workload requirements, you can specify the Slurm version that the controller node uses when you create a cluster. This document explains the supported Slurm controller versions in Cluster Director, and the compatibility rules for the controller node and compute nodes in a cluster.
To learn more about how Cluster Director uses Slurm to handle cluster management, job scheduling, and workload orchestration, see Slurm orchestration in Cluster Director.
Understand Slurm controller versions
When you create a cluster, Cluster Director deploys and manages the
controller node in a fault-tolerant configuration. The controller node runs the
Slurm control daemon (slurmctld)
and the database daemon (slurmdbd).
You can set the Slurm controller version only by using the Google Cloud CLI or
REST API.
Cluster Director supports the following Slurm controller versions:
26.05: use this version for new clusters. If you don't specify a Slurm controller version when you create a cluster, then Cluster Director uses version 26.05 by default.
25.05: use this version for testing and compatibility with existing clusters.
To review which Slurm version an OS image family uses, see Supported OS images for Cluster Director.
Compute node image compatibility
Slurm requires that the compute nodes in a cluster run a Slurm version that is the same as or earlier than the version that your controller node runs. Compute nodes can't communicate with a controller node that runs an earlier Slurm version.
The following table describes the compatibility between controller versions and compute node versions:
| Slurm controller version | Slurm compute node version | Supported? | Details |
|---|---|---|---|
| 26.05 | 26.05 | Yes | The recommended configuration for new clusters. |
| 26.05 | 25.05 | Yes | The controller node is backward-compatible with older compute nodes. |
| 25.05 | 25.05 | Yes | The standard configuration for legacy clusters. |
| 25.05 | 26.05 | No | Attempting to create a cluster or add nodesets to an existing cluster will fail. |
To check the Slurm controller version before you add a nodeset to an existing cluster, view the cluster details
by using the gcloud CLI or REST API, and then inspect the
orchestrator.slurm.controllerVersion field.