File transfer configuration - Boto3 1.34.87 documentation
When uploading, downloading, or copying a file or S3 object, the AWS SDK for Python automatically manages retries and multipart and non-multipart transfers.
The management operations are performed by using reasonable default settings that are well-suited for most scenarios. To handle a special case, the default settings can be configured to meet requirements.
Configuration settings are stored in aboto3.s3.transfer.TransferConfig object. The object is passed to
a transfer method (upload_file, download_file, etc.) in the Config=parameter.
The remaining sections demonstrate how to configure various transfer operations
with the TransferConfig object.
Multipart transfers#
Multipart transfers occur when the file size exceeds the value of themultipart_threshold attribute.
The following example configures an upload_file transfer to be multipart
if the file size is larger than the threshold specified in theTransferConfig object.
import boto3from boto3.s3.transfer import TransferConfig# Set the desired multipart threshold value (5GB)GB = 1024 ** 3config = TransferConfig(multipart_threshold=5*GB)# Perform the transfers3 = boto3.client('s3')s3.upload_file('FILE_NAME', 'BUCKET_NAME', 'OBJECT_NAME', Config=config)
Concurrent transfer operations#
The maximum number of concurrent S3 API transfer operations can be tuned to
adjust for the connection speed. Set the max_concurrency attribute to
increase or decrease bandwidth usage.
The attribute’s default setting is 10. To reduce bandwidth usage, reduce the value; to increase usage, increase it.
# To consume less downstream bandwidth, decrease the maximum concurrencyconfig = TransferConfig(max_concurrency=5)# Download an S3 objects3 = boto3.client('s3')s3.download_file('BUCKET_NAME', 'OBJECT_NAME', 'FILE_NAME', Config=config)
Threads#
Transfer operations use threads to implement concurrency. Thread use can be
disabled by setting the use_threads attribute to False.
If thread use is disabled, transfer concurrency does not occur. Accordingly,
the value of the max_concurrency attribute is ignored.
# Disable thread use/transfer concurrencyconfig = TransferConfig(use_threads=False)s3 = boto3.client('s3')s3.download_file('BUCKET_NAME', 'OBJECT_NAME', 'FILE_NAME', Config=config)
