WIP: Add gRPC keep alive

[jjcollinge]

Signed-off-by: Jonathan Collinge jonathancollinge@live.com

Description

Adds support for setting gRPC keep alives.
Can be set via builder or via env vars to keep consistent with dapr/java-sdk#1382.

Issue reference

We strive to have all PR being opened based on an issue, where the problem or feature have been discussed prior to implementation.

Please reference the issue this PR will close: #[issue number]

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles correctly
• Created/updated tests
• Extended the documentation

[WhitWaldo]

Thank you for the contribution - there's a lot on the gRPC side that needs another pass to offload to the gRPC client instead of trying to handle it in the SDK and I look forward to seeing what you come up with here.

That said, could you please target the release-1.16 branch? Master is reserved for the current release (e.g. bug fixes) and this would not be part of that.

[jjcollinge]

Thank you for the contribution - there's a lot on the gRPC side that needs another pass to offload to the gRPC client instead of trying to handle it in the SDK and I look forward to seeing what you come up with here.

That said, could you please target the release-1.16 branch? Master is reserved for the current release (e.g. bug fixes) and this would not be part of that.

Thanks @WhitWaldo - I've rebased on release-1.16 and moved the configuration to the grpc client builders. It's been many years since I've written csharp and I'm not familiar with this SDK so will need your guidance to push me in the right direction please.

[WhitWaldo]

That's quite all right. Let me know if you run into an issue and I'd be happy to help out. Also feel free to ping or DM me on Discord.

[WhitWaldo]

I'm going to hold off on merging this until DurableTask is stable as I don't want to introduce additional opportunities for unrelated failures.