v3.9.0

The MongoDB Rust driver team is pleased to announce the v3.9.0 release of the mongodb crate, now available for download from crates.io.

This release adds support for the new baseBackoffMS server error field. The driver now uses the value for baseBackoffMS reported by the server in its retry backoff calculations. This new feature is part of MongoDB's Intelligent Workload Management (IWM) and is available on MongoDB Atlas server versions 9.0+.

Full Release Notes

New Features

• RUST-2409 CSFLE/QE Support for HTTP Proxies (#1756)
• RUST-2412 Send afterClusterTime on writes in causally-consistent sessions (#1742)
• RUST-2446 Use baseBackoffMS in retry backoff calculations (#1749)
• RUST-2133 Allow custom aws credential provider (#1781)

Improvements

• RUST-1820 Use raw documents and smart truncation for tracing and otel (#1757)
• RUST-2396 Report timeout errors for convenient transactions (#1759)
• RUST-2411 Remove support for MongoDB 4.2 (#1770)

Bugfixes

• RUST-2492 Check for inherited unacknowledged write concerns (#1787)