Working with directory buckets - Amazon Simple Storage Service
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Working with directory buckets

There are two types of Amazon S3 buckets, general purpose buckets and directory buckets. Choose the bucket type that best fits your application and performance requirements:

  • General purpose buckets are the original S3 bucket type and are recommended for most use cases and access patterns. General purpose buckets also allow objects that are stored across all storage classes, except S3 Express One Zone in Amazon Availability Zones and S3 One Zone-IA in Amazon Local Zones.

  • Directory buckets support bucket creation in the following bucket location types: Availability Zone or Local Zone. For low latency use cases, you can create a directory bucket in a single Availability Zone to store data. Directory buckets in Availability Zones support the S3 Express One Zone storage class. S3 Express One Zone storage class is recommended if your application is performance sensitive and benefits from single-digit millisecond PUT and GET latencies. For data residency use cases, you can create a directory bucket in a single Amazon Dedicated Local Zone (DLZ) to store data. Directory buckets in Local Zones support the S3 One Zone-Infrequent Access (S3 One Zone-IA; Z-IA) storage class. To learn more about creating directory buckets in Availability Zones, see High performance workloads. To learn more about creating directory buckets in Local Zones, see Data residency workloads.

Directory buckets organize data hierarchically into directories as opposed to the flat storage structure of general purpose buckets. There aren't prefix limits for directory buckets, and individual directories can scale horizontally.

You can create up to 100 directory buckets in each of your Amazon Web Services accounts, with no limit on the number of objects that you can store in a bucket. Your bucket quota is applied to each Region in your Amazon Web Services account. If your application requires increasing this limit, contact Amazon Web Services Support.

Important

Directory buckets that have no request activity for a period of at least 90 days transition to an inactive state. While in an inactive state, a directory bucket is temporarily inaccessible for reads and writes. Inactive buckets retain all storage, object metadata, and bucket metadata. Existing storage charges apply to inactive buckets. If you make an access request to an inactive bucket, the bucket transitions to an active state, typically within a few minutes. During this transition period, reads and writes return an HTTP 503 (Service Unavailable) error code.

The following topics provide information about directory buckets. For more information about general purpose buckets, see Buckets overview.

For more information about directory buckets, see the following topics.

Directory bucket names

A directory bucket name consists of a base name that you provide and a suffix that contains the ID of the Zone (Availability Zone or Local Zone) that your bucket is located in. Directory bucket names must use the following format and follow the naming rules for directory buckets:

bucket-base-name--zone-id--x-s3

For example, the following directory bucket name contains the Availability Zone ID usw2-az1:

bucket-base-name--usw2-az1--x-s3

For more information, see Directory bucket naming rules.

Directories

Directory buckets organize data hierarchically into directories as opposed to the flat sorting structure of general purpose buckets.

With a hierarchical namespace, the delimiter in the object key is important. The only supported delimiter is a forward slash (/). Directories are determined by delimiter boundaries. For example, the object key dir1/dir2/file1.txt results in the directories dir1/ and dir2/ being automatically created, and the object file1.txt being added to the /dir2 directory in the path dir1/dir2/file1.txt.

The directory bucket indexing model returns unsorted results for the ListObjectsV2 API operation. If you need to limit your results to a subsection of your bucket, you can specify a subdirectory path in the prefix parameter, for example, prefix=dir1/.

Key names

For directory buckets, subdirectories that are common to multiple object keys are created with the first object key. Additional object keys for the same subdirectory use the previously created subdirectory. This model gives you flexibility in choosing object keys that are best suited to the application, with equal support for sparse and dense directories.

Access management

Directory buckets have all S3 Block Public Access settings enabled by default at the bucket level. S3 Object Ownership is set to bucket owner enforced and access control lists (ACLs) are disabled. These settings can't be modified.

By default, users don't have permissions for directory buckets. To grant access permissions for directory buckets, you can use IAM to create users, groups, or roles and attach permissions to those identities. For more information, see Authorizing Regional endpoint API operations with IAM.

Creating and using directory buckets

For more information about working with directory buckets, see the following topics.