S3 API Compatibility

This page documents S3 APIs supported by MinIO AIStor. For reference documentation on any given API, see the corresponding documentation for Amazon S3.

• CopyObject

• DeleteObject

• DeleteObjects

• DeleteObjectTagging

• GetObject

• GetObjectAttributes

• GetObjectTagging

• HeadObject

• ListObjects

• ListObjectsV2

• ListObjectVersions

• PutObject

• PutObjectTagging

• RestoreObject

• SelectObjectContent

MinIO AIStor supports conditional operations using the following HTTP headers:

DeleteObjects supports conditional deletes using the <ETag> element in the request body.

• GetObjectRetention

• PutObjectRetention

• GetObjectLegalHold

• PutObjectLegalHold

• GetObjectLockConfiguration

• PutObjectLockConfiguration

• GetObjectAcl
• PutObjectAcl

• AbortMultipartUpload

• CompleteMultipartUpload

• CreateMultipartUpload

• ListMultipartUploads

• ListParts

• UploadPart

• UploadPartCopy

• ListMultipartUploads requires the exact object name as a prefix.

• The AbortIncompleteMultipartUpload lifecycle action is not supported with PutBucketLifecycle.

• CreateBucket

• DeleteBucket

• DeleteBucketEncryption

• DeleteBucketTagging

• GetBucketEncryption

• GetBucketLocation

• GetBucketTagging

• GetBucketVersioning

• HeadBucket

• ListBuckets

• ListDirectoryBuckets

• PutBucketEncryption

• PutBucketTagging

• PutBucketVersioning

• PutBucketCors

• DeleteBucketCors

• PutBucketAnalyticsConfiguration

• ListBucketAnalyticsConfigurations

• DeleteBucketAnalyticsConfiguration

• CreateSession

• GetBucketReplication

• PutBucketReplication

• DeleteBucketReplication

• GetBucketLifecycle

• GetBucketLifecycleConfiguration

• PutBucketLifecycle

• PutBucketLifecycleConfiguration

• DeleteBucketLifecycle

• GetBucketNotification

• GetBucketNotificationConfiguration

• PutBucketNotification

• PutBucketNotificationConfiguration

• GetBucketPolicy

• GetBucketPolicyStatus

• PutBucketPolicy

• DeleteBucketPolicy

• GetBucketInventoryConfiguration
• PutBucketInventoryConfiguration
• DeleteBucketInventoryConfiguration
• GetBucketMetricsConfiguration
• PutBucketMetricsConfiguration
• DeleteBucketMetricsConfiguration
• PutBucketWebsite
• GetBucketLogging
• PutBucketLogging
• PutBucketAccelerateConfiguration
• DeleteBucketAccelerateConfiguration
• PutBucketRequestPayment
• DeleteBucketRequestPayment
• PutBucketAcl
• HeadBucketAcl
• GetPublicAccessBlock
• PutPublicAccessBlock
• DeletePublicAccessBlock
• GetBucketOwnershipControls
• PutBucketOwnershipControls
• DeleteBucketOwnershipControls
• GetBucketIntelligentTieringConfiguration
• PutBucketIntelligentTieringConfiguration
• ListBucketIntelligentTieringConfigurations
• DeleteBucketIntelligentTieringConfiguration
• GetBucketAnalyticsConfiguration

• For calls to BucketACL or ObjectACL operations, use Policies.
• For calls to BucketWebsite operations, use caddy or nginx.
• For calls to BucketAnalytics, BucketMetrics, or BucketLogging operations, use Bucket notifications.

MinIO AIStor extends the S3 API with additional capabilities, including Object Lambda for on-the-fly object transformation during retrieval and the S3 ZIP Extension for reading individual files inside ZIP archives without extracting them first.

On a deployment running the RDMA build, GetObject, PutObject, and UploadPart can transfer object data directly between client memory and the server over RDMA, using the AWS S3 RDMA protocol. GetObject writes into the client’s buffer; PutObject and UploadPart read from it. That buffer is usually GPU memory, which is where RDMA pays off most, but host memory works too and needs no GPU.

The client opts in per request with a header; there is no server setting.

On a successful RDMA transfer the server sets Content-Length: 0, because the object bytes did not travel in the HTTP response.

When the server declines, it returns an S3 error response rather than serving the object over HTTP. Retrying without the x-amz-rdma-token header is the client’s responsibility. The MinIO SDKs below handle this automatically.

Reliable Connection clients first perform a handshake at POST /rdma/connect, exchanging descriptors through the same x-amz-rdma-token header. Dynamically Connected clients do not use this route.

S3 over RDMA is supported by the MinIO SDKs for Go, C++, Rust, and Python.

Each of them uses NVIDIA cuObjClient to move the object payload between GPU memory and the network adapter.

For worked examples in each language, see Transfer Objects over RDMA.

For deployment, see RDMA acceleration.

When MinIO AIStor runs in S3 Express mode, the supported S3 API surface differs from the default S3 API mode. S3 Express mode also adds the AppendObject behavior, which lets a client append data to an existing object by issuing a PutObject request with the x-amz-write-offset-bytes header. For the list of operations supported and disabled in S3 Express mode, see S3 Express mode.

In addition to the standard S3 error codes, MinIO AIStor returns the following MinIO-specific error codes:

KMS-backed operations return these codes, including when the KMS itself is unreachable:

A request that the client cancels while a KMS operation is in flight returns status 499 rather than a KMS error.