Replace HTTP with TCP

[gbryant-arm]

Requested feature
We propose to replace the HTTP layer with TCP between Veracruz-Client and the runtime manager.
In practice the HTTP client (on Veracruz-Client) and server (on Veracruz-Server) will be replaced with a TCP client and a TCP repeater (client & server) respectively. The stack on the runtime manager is not affected as it doesn't use HTTP.
This will reduce latency within the system by stripping down the network stack (i.e. less packet processing and no base64 encoding/decoding in particular) and using TCP's congestion control to transmit batches of TLS records more efficiently between Veracruz-Client and Veracruz-Server.

Motivation
Clients currently communicate with the runtime manager via TLS over HTTP. As a result protobuf messages are encrypted in 16KB TLS records, sent one by one to the other endpoint. The overall round-trip latency is hence subject to the processing time on the runtime manager side. This will become a major bottleneck when the latency between Veracruz-Client and Veracruz-Server increases.
#277 made some strides towards reducing the overall latency between Veracruz-Client and runtime manager but hasn't addressed this bottleneck.

[Immy-delish]

Hello, I am an outreachy applicant. I would like to replace the HTTP layer with TCP between Veracruz-Client and the runtime manager, if this solution could solve the issue.

[dreemkiller]

@Immy-delish I would not advise this issue as a first issue.
It is a very complicated change that affects many disparate code packages across all of the different platforms that we support (including AWS Nitro enclaves, which would require you to launch and run AWS EC2 instances outside of the free tier - costing you money). There are several issues labeled with "Good first Issue" (https://github.com/veracruz-project/veracruz/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22) that would be a better place to start.

[Immy-delish]

Alright, Thank you so much Derek for this.

…

On Mon, Apr 18, 2022, 10:31 PM Derek D. Miller ***@***.***> wrote: @Immy-delish <https://github.com/Immy-delish> I would not advise this issue as a first issue. It is a very complicated change that affects many disparate code packages across all of the different platforms that we support (including AWS Nitro enclaves, which would require you to launch and run AWS EC2 instances outside of the free tier - costing you money). There are several issues labeled with "Good first Issue" ( https://github.com/veracruz-project/veracruz/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22) that would be a better place to start. — Reply to this email directly, view it on GitHub <#378 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AROTTM76UBJ2D5S6TPAWANTVFWZ7RANCNFSM5SIV36LQ> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[egrimley-arm]

HTTP was replaced with TCP by #542, but with TCP still being used in an HTTP-like way, so there is more work to do, for which I have just created a new issue: #558.