Change the consistency level

Contributors netapp-perveilerk netapp-lhalbert

If you are using an S3 tenant, you can use the Tenant Manager or the Tenant Management API to change the consistency control for operations performed on the objects in S3 buckets.

What you’ll need
  • You must be signed in to the Tenant Manager using a supported web browser.

  • You must belong to a user group that has the Manage All Buckets or the Root Access permission. These permissions override the permissions settings in group or bucket policies. See Tenant management permissions.

About this task

Consistency level makes a trade-off between the availability of the objects and the consistency of those objects across different Storage Nodes and sites. In general, you should use the Read-after-new-write consistency level for your buckets. If the Read-after-new-write consistency level does not meet the client application’s requirements, you can change the consistency level by setting the bucket consistency level or by using the Consistency-Control header. The Consistency-Control header overrides the bucket consistency level.

Note When you change a bucket’s consistency level, only those objects that are ingested after the change are guaranteed to meet the revised level.
Steps
  1. Select STORAGE (S3) > Buckets.

  2. Select the bucket name from the list.

    The bucket details page appears.

  3. Select Bucket options > Consistency level.

  4. Select a consistency level for operations performed on the objects in this bucket.

    Consistency level Description

    All

    All nodes receive the data immediately, or the request will fail.

    Strong-global

    Guarantees read-after-write consistency for all client requests across all sites.

    Strong-site

    Guarantees read-after-write consistency for all client requests within a site.

    Read-after-new-write (Default)

    Provides read-after-write consistency for new objects and eventual consistency for object updates. Offers high availability, and data protection guarantees. Most closely matches Amazon S3 consistency guarantees.

    Note: If your application attempts HEAD or GET operations on keys that do not exist, set the Consistency Level to Available, unless you require Amazon S3 consistency guarantees. Otherwise, a high number of 500 Internal Server errors can result if one or more Storage Nodes are unavailable.

    Available (eventual consistency for HEAD or GET operations)

    Behaves the same as the Read-after-new-write consistency level, but provides eventual consistency for HEAD and GET operations. Offers higher availability for HEAD and GET operations than Read-after-new-write if Storage Nodes are unavailable. Differs from Amazon S3 consistency guarantees for HEAD and GET operations.

  5. Select Save changes.