Cost Optimization¶

User Cost Optimizations¶

Suggestions for users running workflows.

Set The Workflows Pod Resource Requests¶

Suitable if you are running a workflow with many homogeneous pods.

Resource duration shows the amount of CPU and memory requested by a pod and is indicative of the cost. You can use this to find costly steps within your workflow.

Smaller requests can be set in the pod spec patch's resource requirements.

Use A Node Selector To Use Cheaper Instances¶

You can use a node selector for cheaper instances, e.g. spot instances:

nodeSelector:
  "node-role.kubernetes.io/argo-spot-worker": "true"

Consider trying Volume Claim Templates or Volumes instead of Artifacts¶

Suitable if you have a workflow that passes a lot of artifacts within itself.

Copying artifacts to and from storage outside of a cluster can be expensive. The correct choice is dependent on what your artifact storage provider is vs. what volume they are using. For example, we believe it may be more expensive to allocate and delete a new block storage volume (AWS EBS, GCP persistent disk) every workflow using the PVC feature, than it is to upload and download some small files to object storage (AWS S3, GCP cloud storage).

On the other hand if you are using a NFS volume shared between all your workflows with large artifacts, that might be cheaper than the data transfer and storage costs of object storage.

Consider:

Data transfer costs (upload/download vs. copying)
Data storage costs (object storage vs. volume)
Requirement for parallel access to data (NFS vs. block storage vs. artifact)

When using volume claims, consider configuring Volume Claim GC. By default, claims are only deleted when a workflow is successful.

Limit The Total Number Of Workflows And Pods¶

Suitable for all.

A workflow (and for that matter, any Kubernetes resource) will incur a cost as long as it exists in your cluster, even after it's no longer running.

The workflow controller memory and CPU needs to increase linearly with the number of pods and workflows you are currently running.

You should delete workflows once they are no longer needed. You can enable the Workflow Archive to continue viewing them after they are removed from Kubernetes.

Limit the total number of workflows using:

Active Deadline Seconds - terminate running workflows that do not complete in a set time. This will make sure workflows do not run forever.
Workflow TTL Strategy - delete completed workflows after a set time.
Pod GC - delete completed pods. By default, Pods are not deleted.
CronWorkflow history limits - delete successful or failed workflows which exceed the limit.

Example

spec:
  # must complete in 8h (28,800 seconds)
  activeDeadlineSeconds: 28800
  # keep workflows for 1d (86,400 seconds)
  ttlStrategy:
    secondsAfterCompletion: 86400
  # delete all pods as soon as they complete
  podGC:
    strategy: OnPodCompletion

You can set these configurations globally using Default Workflow Spec.

Changing these settings will not delete workflows that have already run. To list old workflows:

argo list --completed --since 7d

v2.9 and after

To list/delete workflows completed over 7 days ago:

argo list --older 7d
argo delete --older 7d

Operator Cost Optimizations¶

Suggestions for operators who installed Argo Workflows.

Set Resources Requests and Limits¶

Suitable if you have many instances, e.g. on dozens of clusters or namespaces.

Set resource requests and limits for the workflow-controller and argo-server, e.g.

requests:
  cpu: 100m
  memory: 64Mi
limits:
  cpu: 500m
  memory: 128Mi

This above limit is suitable for the Argo Server, as this is stateless. The Workflow Controller is stateful and will scale to the number of live workflows - so you are likely to need higher values.

Configure Executor Resource Requests¶

Suitable for all - unless you have large artifacts.

Configure workflow-controller-configmap.yaml to set the executor.resources:

executor: |
  resources:
    requests:
      cpu: 100m
      memory: 64Mi
    limits:
      cpu: 500m
      memory: 512Mi

The correct values depend on the size of artifacts your workflows download. For artifacts > 10GB, memory usage may be large - #1322.