Low Priority Compute Node Considerations
Please read the following carefully concerning pools allocated with low- priority compute nodes. You may also want to read the Azure Batch Low Priority Compute Node documentation.
Pool Allocation and Resizing
- Low priority compute nodes can only be allocated with Batch Service (i.e., not User Subscription) Batch accounts.
- Pool and compute node allocation may take up to the full resize timeout and not reach full allocation with low priority if a low priority node is pre-empted and the target number of low priority nodes cannot be reached.
- Pool allocation is considered successful if the target number of dedicated nodes is reached. If the number of low priority nodes cannot be reached, a resize error will be logged, but the allocation will continue such as continuing with SSH user provisioning and data ingress.
- An SSH user is recommended to be provisioned so commands that rely on
SSH access for low-priority nodes such as
pool images updateare able to be run.
- Certain commands may timeout and fail with low priority nodes. As nodes can be pre-empted at any time, commands that rely on interacting with the node such as direct SSH access, task termination, etc. may not complete successfully.
pool images updatecommand will only run as a Batch job if a compute pool is completely comprised of dedicated nodes. For pools with any low-priority nodes, images will be updated individually on each node via SSH, thus requiring an SSH user to be active and allocated on the nodes.
- GlusterFS on compute can only be used on pure dedicated Batch pools. Allocation will fail if such a shared data volume is specified on a pool with low priority nodes or if a resize to include low priority nodes is attempted with a GlusterFS on compute shared data volume.