I would like to bring your awareness to a PR that proposes to upgrade datafusion / arrow flight to use tokio 1.0: https://github.com/apache/arrow/pull/9230
Given that tokio 1.0 is not compatible with versions prior to 1.0 this upgrade will mean, effectively, that all projects that depend on arrow / datafusion will also have to upgrade their versions of tokio as well when they take the next version of Arrow. I think this is happening all across the Rust ecosystem as the new versions of tokio percolate to downstreams, but I wanted to raise awareness and invite others to chime in before we merged it. Andrew
