Enabling or disabling last access time updates

When grid administrators create the Information Lifecycle Management (ILM) rules for a StorageGRID Webscale system, they can optionally specify that an object's last access time be used to determine whether to move that object to a different storage location. If you are using an S3 tenant, you can take advantage of such rules by enabling last access time updates for the objects in an S3 bucket.

Before you begin

These instructions only apply to StorageGRID Webscale systems that include at least one ILM rule that uses the Last Access Time option in its placement instructions. You can ignore these instructions if your StorageGRID Webscale system does not include such a rule.

About this task

Last Access Time is one of the options available for the Reference Time placement instruction for an ILM rule. Setting the Reference Time for a rule to Last Access Time lets grid administrators specify that objects be placed in certain storage locations based on when those objects were last retrieved (read or viewed).

For example, to ensure that recently viewed objects remain on faster storage, a grid administrator can create an ILM rule specifying the following:
  • Objects that have been retrieved in the past month should remain on local Storage Nodes.
  • Objects that have not been retrieved in the past month should be moved to an off-site location.
Note: See the instructions for administering StorageGRID Webscale for more information.

By default, updates to last access time are disabled. If your StorageGRID Webscale system includes an ILM rule that uses the Last Access Time option, you must enable updates to last access time for the S3 buckets specified in that rule.

The table summarizes the behavior applied to all objects in the bucket when last access time is disabled or enabled.
Type of request Behavior if last access time is disabled (default) Behavior if last access time is enabled
Last access time updated? Object added to ILM evaluation queue? Last access time updated? Object added to ILM evaluation queue?
Request to retrieve an object, its access control list, or its metadata No No Yes Yes
Request to update an object’s metadata Yes Yes Yes Yes
Request to copy an object from one bucket to another
  • No, for the source copy
  • Yes, for the destination copy
  • No, for the source copy
  • Yes, for the destination copy
  • Yes, for the source copy
  • Yes, for the destination copy
  • Yes, for the source copy
  • Yes, for the destination copy
Request to complete a multipart upload Yes, for the assembled object Yes, for the assembled object Yes, for the assembled object Yes, for the assembled object
Before enabling last access time for a bucket, be aware that the enabled setting can reduce StorageGRID Webscale performance, especially in systems with small objects. The performance impact occurs because StorageGRID Webscale must perform these additional steps every time objects are retrieved:
  • Update the objects with new timestamps
  • Add the objects to the ILM queue, so they can be reevaluated against current ILM rules and policy

Steps

  1. Click S3 > Buckets.
  2. Select a bucket from the list.
  3. Click Configure Last Access Setting.
  4. Select the check box if you to want to update the last access time when retrieving an object in this bucket, or unselect the box to if you want to disable last access time updates.

    screenshot showing dialog box for setting last access time updates
    Attention: Updating the last access time when an object is retrieved can reduce performance, especially for small objects
  5. Click Save.