We support two forms of plugins for external storage (https://github.com/jaegertracing/jaeger/tree/main/plugin/storage/grpc)

• a sidecar model using hashicorp/go-plugin library
• a remote storage implementing gRPC Remote Storage API

Even though the recent Hashicorp license changes (cncf/foundation#617) may not affect the go-plugin library, the dual plugin model creates unnecessary complication and requires extra code to maintain. And while I did not try it myself, I expect that the sidecar model can be reproduced relatively easily by the users themselves, e.g. by running the existing plugin binaries as a sidecar using their own orchestration mechanisms.

The proposal has been accepted. Roadmap:

• Give a 6-month grace period for existing users or sidecar plugins to switch to remote gRPC model
  • Add deprecation notice to CLI flags for grpc-storage-plugin sidecar model #4744
• Remove the sidecar code & examples
  • Remove support for gRPC-Plugin #5388
• Clean up the code for gRPC Remote Storage
  • Replace grpc-plugin storage type name with just grpc #5442
• Remove github.com/hashicorp/go-plugin dependency #5446
• Update documentation
  • Remove grpc-plugin storage type documentation#702
• Completely remove "grpc-plugin" as storage type #5741