The Atlas Serverless 2 team plans to reuse the existing Server library libmessage to support the wire protocol in Serverless Proxy built on Envoy. However, libmessage has a dependency on the multitenancy library. This dependency added many indirect dependencies to the original ~20 mongo dependencies. This adds risks to integrating it into Serverless Proxy on a few aspects.
 

• Library API - all the dependencies will be a part of the contract and accessible by library consumers.
• Library behavior - we need to audit the behavior of the library, like the network library, to make sure they don't have side effects or security issues.
• Code compatibility - there might be potential macro (more likely) and namespace (less likely) conflicts. Global variables and initialization could also affect the final executable.
• Security risk - it will be a large surface of security risk.
• Dev productivity - it will slow down the compilation.