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 (HEAD/GET/PUT/DEL) Including ListObjects and ListObjectsV2

• Bucket Lifecycle (GET/PUT/DEL)

• Bucket Policy (GET/PUT/DEL)

• Bucket Tagging (GET/PUT/DEL)

• Object (GET/PUT/DEL)

• Object Tagging (GET/PUT/DEL)

• Object Multipart (POST Create/Complete, GET/DEL/PUT, GET Parts)

For a multipart object upload, the bucket’s free capacity must be at least twice the size of the object until the upload is complete.

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

Supported checksum

Only MD5 checksum algorithm is supported.

Lifecycle configuration

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