Wombat

WAF-SUS-120 – Batch and HPC workloads SHOULD run off-peak where SLA constraints allow

Pillar: Sustainability | Severity: 🟢 Low | Category: Sustainability Efficiency | Automatable: Medium

Description

Batch, report generation, HPC, and data processing workloads SHOULD be scheduled during off-peak or high-renewable-energy hours. Scheduler configurations MUST document SLA constraints and acceptable time windows. Preemptible/Spot capacity SHOULD be combined with off-peak scheduling where feasible. Energy and cost savings of time-shifting MUST be tracked and reported.

Rationale

Risk Description

Risk

Running batch workloads during peak hours wastes energy from high-carbon grid mix and increases cost.

Risk

Missing scheduling constraints can violate SLA or delay critical business processes.

Requirements

  • Batch, report generation, HPC, and data processing workloads SHOULD be scheduled during off-peak or high-renewable-energy hours.

  • Scheduler configurations MUST document SLA constraints and acceptable time windows.

  • Preemptible/Spot capacity SHOULD be combined with off-peak scheduling where feasible.

  • Energy and cost savings of time-shifting MUST be tracked and reported.

Implementation Guidance

  1. Document the requirement in a version-controlled policy, ADR, or standard.

  2. Assign ownership and establish a review cadence (e.g., quarterly).

  3. Implement the required configuration as code in Terraform or equivalent IaC.

Maturity Levels

Level Name Criteria

L1

Ad hoc – control not consistently applied

* Die Anforderung ist nicht einheitlich umgesetzt; Nachweis existiert nur punktuell oder fehlt.

L2

Standardised – policy defined and communicated

* Eine dokumentierte Policy oder ein Standard beschreibt die Anforderung.

L3

Integrated – automated validation in CI/CD

* Terraform-Checks oder IaC-Gates prüfen die Anforderung automatisch in CI/CD.

L4

Auditable – metrics and exceptions tracked

* Abdeckung, Ausnahmen und Qualitätsmetriken werden quartalsweise berichtet.

L5

Optimised – continuous improvement based on data

* Die Effektivität wird kontinuierlich gemessen und automatisch optimiert.

Checks

waf-sus-120.tf.aws.batch-schedule

Engine: terraform | Provider: aws | Automated: Yes

AWS Batch compute environments should prefer Spot and off-peak scheduling

AWS Batch compute environments should prefer Spot and off-peak scheduling

Scope: resource — aws_batch_compute_environment, aws_batch_job_queue

Assertions: * compute_resources.spot_iam_fleet_role attribute_exists — Batch compute environment should use Spot capacity.

Remediation: AWS Batch compute environments should prefer Spot and off-peak scheduling

Compliant
# Example compliant with waf-sus-120.tf.aws.batch-schedule
Non-Compliant
# Example non-compliant with waf-sus-120.tf.aws.batch-schedule

waf-sus-120.config.off-peak-schedule

Engine: config | Provider: any | Automated: No

Off-peak scheduling policy must be documented

Off-peak scheduling policy must be documented

Scope: file — docs/sustainability/off-peak-scheduling.md

Assertions: * exists attribute_exists — Off-peak scheduling policy must define SLA windows.

Remediation: Off-peak scheduling policy must be documented

Compliant
# Example compliant with waf-sus-120.config.off-peak-schedule
Non-Compliant
# Example non-compliant with waf-sus-120.config.off-peak-schedule

Evidence

  • Terraform configuration implementing the requirement.

  • Policy, ADR, or standard documenting the requirement.

  • Optional cloud console or API output confirming runtime state.

Related Controls

  • WAF-SUS-010

  • WAF-SUS-020

  • WAF-SUS-030

  • WAF-SUS-110

  • WAF-COST-110

  • WAF-OPS-040 == Regulatory Mapping

  • EU CSRD (Corporate Sustainability Reporting Directive): ESRS E1 – Climate Change

  • GHG Protocol: Scope 2 – Market-based method

  • Green Software Foundation: Carbon Aware Computing – temporal shifting

  • ISO 14001: 6.1.2 – Environmental aspects