AWS Java SDK v2
AWS Java SDK v1 is reaching end of life at the end of 2025. Starting in version 25.06.0-edge, Nextflow uses AWS Java SDK v2 in the nf-amazon plugin.
This migration introduced several breaking changes to the aws.client config scope, including new options and removed options. This page describes these changes and how they affect your Nextflow configuraiton.
New HTTP client
The HTTP client used by SDK v2 does not support overriding certain advanced HTTP options. As a result, the following config options are no longer supported:
aws.client.protocolaws.client.signerOverrideaws.client.socketRecvBufferSizeHintaws.client.socketSendBufferSizeHintaws.client.userAgent
S3 transfer manager
The S3 transfer manager is a subsystem of SDK v2 which handles S3 transfers, including S3 uploads and downloads.
The concurrency and throughput of the S3 transfer manager can be configured manually using the aws.client.maxConcurrency and aws.client.maxNativeMemory config options. Alternatively, the aws.client.targetThroughputInGbps config option can be used to set the previous two options automatically based on a target throughput.
Multi-part uplaods
Multi-part uploads are handled by the S3 transfer manager. The aws.client.minimumPartSize and aws.client.multipartThreshold config options can be used to control when and how multi-part uploads are performed.
The following multi-part upload options are no longer supported:
aws.client.uploadChunkSizeaws.client.uploadMaxAttemptsaws.client.uploadMaxThreadsaws.client.uploadRetrySleep