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Configuring user quotas¶

Since REANA 0.8.0, it is possible to configure user quotas to limit the usage of resources, such as CPU and disk storage. This page describes how to enable quotas on your REANA cluster and how to set usage limits. If you are looking for documentation from the user perspective, please check this page.

Enabling and disabling quotas¶

Quotas are enabled by default in REANA. If you would like to disable them, you can set the quota.enabled Helm value to false.

REANA automatically creates two user quota resources for you:

cpu to limit the amount of CPU time available to run workflows;
disk to limit the total storage space in user workflow's workspaces.

In addition to enabling quotas, you might want to decide how frequently the quota resources usage should be tracked and updated. This is done using two options:

quota.periodic_update_policy Helm value defining a policy where users' quota resources usage is updated periodically via a cron job. The value is a cron expression and it indicates how frequently the cron job should run. By default, the value is set to "0 3 * * *", meaning that the quota usage updates are carried out daily at 03:00 in the morning.
quota.workflow_termination_update_policy Helm value defining a policy where users' quota resources usage is updated as soon as each workflow run terminates. This policy is not enabled by default because it could lead to slower workflow termination times when the REANA system runs many concurrent user workflows.

Here is an example of a mixed configuration where, in addition to nightly CPU and disk quota usage updates, the CPU usage is also updated immediately after each workflow run terminates:

quota:
  enabled: true
  # update quota usage everyday at 3AM
  periodic_update_policy: "0 3 * * *"
  # after workflow finishes or fails update its cpu usage
  workflow_termination_update_policy: "cpu"

Setting default quota limits¶

When user quotas are enabled, no limit on the actual usage of resources by the users is enforced by default. You could however set a default quota limit that will apply to each user by means of setting the quota.default_disk_limit and quota.default_cpu_limit Helm values:

quota:
  default_disk_limit: 10737418240  # bytes (10 GiB)
  default_cpu_limit: 36000000      # milliseconds (10 hours)
  ...

Individual users will be able to run as many workflows as they want, provided that the total CPU usage time stays under 10 hours and the total consumed disk space stays under 10 GiB.

Warning

If the default quota values are changed, they will only be applied to newly created users. Users that already exist will not be affected by this change.

Setting individual quota limits¶

In addition to setting the default quota limits for all users, you may want to set different quota usage limits for different specific groups of users. This can be done via the reana-admin tool that is present in the reana-server pod.

Log in to the reana-server pod:

$ kubectl exec -i -t deployment/reana-server -- /bin/bash

You can now set a custom quota limit to selected users:

# flask reana-admin quota-set -e john.doe@example.org -r disk -l 250000 --admin-access-token $REANA_ACCESS_TOKEN
Quota limit 250000 for 'disk (shared storage)' successfully set to users ('john.doe@example.org',).

You can learn more about the quota-set administrative command options by running flask reana-admin quota-set --help.