S3 supported APIs and limitations

This page describes limitations concerning the S3 service and protocol implementation.

Supported URL styles for API requests to S3 buckets

WEKA supports two URL styles for API requests to S3 buckets: path-style and virtual-hosted-style.

Style	URL format
Path-style	https://s3.domain-name.com/bucket-name/object-name
Virtual-hosted-style	https://bucket-name.s3.domain-name.com/object-name

The difference between the styles is subtle but significant. When using a URL to reference an object, the DNS resolution maps the subdomain name to an IP address. With the path style, the subdomain is always s3.domain-name.com. With the virtual-hosted-style, the subdomain is specific to the bucket.

The addressing style used to construct the request is determined by the S3 client sending the request.

Supported S3 APIs

The following standard S3 APIs are supported:

• Bucket APIs:

  • HEAD Bucket

  • CREATE Bucket

  • DELETE Bucket

  • LIST Objects

  • LIST Objects V2

  • LIST Buckets

• Bucket Lifecycle APIs:

  • GET Bucket Lifecycle

  • PUT Bucket Lifecycle

  • DELETE Bucket Lifecycle

• Bucket Policy APIs:

  • GET Bucket Policy

  • PUT Bucket Policy

  • DELETE Bucket Policy

• Bucket Tagging APIs:

  • GET Bucket Tagging

  • PUT Bucket Tagging

  • DELETE Bucket Tagging

• Object APIs:

  • GET Object

  • PUT Object

  • DELETE Object

  • DELETE Objects

  • COPY Object

  • HEAD Object

• Object Tagging APIs:

  • GET Object Tagging

  • PUT Object Tagging

  • DELETE Object Tagging

• Object Multipart APIs:

  • POST Create Multipart Upload

  • POST Complete Multipart Upload

  • GET Object Parts

  • PUT Part

  • DELETE Multipart Upload

• Bucket Notification APIs:

  • GET Bucket Notification

  • GET Bucket Notification Configuration

  • PUT Bucket Notification

  • PUT Bucket Notification Configuration

General limits

Item	Limits
Maximum number of buckets	10000
Maximum object size	5 TiB
Maximum number of parts per upload	10000
Part numbers	1 to 10000 (inclusive)
Part size	5 MiB to 5 GiB. The last part can be < 5 MiB
Maximum number of parts returned for a list parts request	1000
Maximum number of multipart uploads returned in a list multipart uploads request	1000
User-defined metadata per object	2 KB
Maximum length of an S3 IAM user policy	2048
Maximum number of S3 IAM user policies	1024
Maximum number of S3 regular users	1024
Maximum number of S3 service accounts	5000
Maximum number of S3 STS credentials	5000

Naming limitations

Buckets

• Bucket names must be between 3 and 63 characters long.

• Bucket names can consist only of lowercase letters, numbers, dots ("."), and hyphens ("-").

• Bucket names must begin and end with a letter or number.

• Bucket names must not be formatted as IP addresses (for example, 192.168.5.4).

• Bucket names must be unique across the cluster.

Objects

• Object key names may be up to 1024 characters long.

• An object prefix cannot begin with a forward slash ("/").

• Adding a forward slash ("/") in the object's prefix after the first character is interpreted as a directory. Such directory segments are limited to 255 characters.

• For naming convention details, see Creating object key names (AWS portal).

• Ensure the object key name is also compatible with protocols other than S3. Specifically, avoid special characters that might be unsupported in the other protocols.

Policy limitations

Supported S3 policy actions

The S3 protocol implementation supports the following policy actions:

• s3:* This wildcard is supported for IAM policies but not for bucket policies.

• s3:AbortMultipartUpload

• s3:CreateBucket

• s3:DeleteBucket

• s3:DeleteBucketPolicy

• s3:DeleteObject

• s3:GetBucketLocation

• s3:GetLifecycleConfiguration

• s3:PutLifecycleConfiguration

• s3:ListBucketMultipartUploads

• s3:ListMultipartUploadParts

• s3:GetBucketPolicy

• s3:GetObject

• s3:ListAllMyBuckets

• s3:ListBucket

• s3:PutBucketPolicy

• s3:PutObject

• s3:GetBucketTagging

• s3:PutBucketTagging

The WEKA S3 implementation supports the following checksum algorithms for data integrity:

• CRC64NVME

• CRC32

• CRC32C

• SHA1

• SHA256

For optimal performance, CRC32 or CRC32C is recommended.

Supported AWS-aligned integrity algorithms

The WEKA system supports end-to-end checksum validation for S3 data integrity protections. The following AWS-aligned integrity algorithms are supported:

• CRC32

• CRC32C

• CRC64NVME

• SHA1

• SHA256

The system provides validation at the whole-object (FULL_OBJECT) and part-level, and supports trailer-based signed chunked uploads. Clients can select the desired algorithm on a per-request basis.

ETag handling in WEKA S3

The WEKA S3 cluster manages the S3 object ETag field using the MD5 algorithm to generate checksums based on the specific upload method. For standard single-part uploads, the returned ETag represents the MD5 checksum of the uploaded data.

In multipart uploads, the system generates an MD5 ETag for each part and ensures sequential validation, deriving the final object ETag from a checksum calculated across the individual parts' ETags.

Lifecycle configuration

WEKA supports the Amazon S3 Lifecycle Configuration elements and definitions, with the limitation of only supporting the lifecycle Expiration action.