[request]: Provide a async API for different async runtime crates and also a sync API

[jmklix]

Discussed in #79

^{Originally posted by howard-quantrend May 12, 2021}
Maybe the sdk could support both popular async runtimes, tokio and async-std using feature flags? In my case, our project only uses the async-std crate, so we need to rewrite the necessary parts of the Rusoto crate ourselves using async-std runtime. It will be great if the aws-sdk-rust supports both runtimes using feature flags, and even better if it provides a blocking sync API too, to support different kind of projects. Actually, this is what the MongoDB rust driver does. Thanks.

You can actually use async-std today by providing your own implementation of the HttpService trait.

If there's enough customer interest, we may consider providing first-class support, but it's worth noting that the workaround exists today. In the current SDK, you would still need to run a 1-threaded Tokio runtime to support retries (which have not yet been made runtime agnostic, although they are planned to be)

[jdisanti]

Multiple async runtime support is tracked in #52. Sync API is tracked in #505

[github-actions]

⚠️COMMENT VISIBILITY WARNING⚠️

Comments on closed issues are hard for our team to see.
If you need more assistance, please either tag a team member or open a new issue that references this one.
If you wish to keep having a conversation with other community members under this issue feel free to do so.