Support for `s390x` (`s390_64`) machine architecture

[joschi]

Is your feature request related to a problem?

The protobuf compiler protoc supports a few non-x86 machine architectures such as aarch64, ppcle, and s390x which are not supported by the gRPC plugin protoc-gen-grpc-java:

Describe the solution you'd like

It would be great if gRPC-Java supported the same machine architectures as Protocol Buffers out of the box.

With aarch64 there's already a non-x86 architecture supported by gRPC-Java and maybe support for the other machine architectures could be implemented in the same way.

[sanjaypujare]

It would be great if gRPC-Java supported the same machine architectures as Protocol Buffers out of the box.

I suspect it is going to be demand based as opposed to just matching the Protocol Buffers functionality. Is there a pointer to what specific changes are needed to support s390x? You could also contribute a PR to add that support.

[joschi]

Is there a pointer to what specific changes are needed to support s390x? You could also contribute a PR to add that support.

Unfortunately I neither have experience with the s390x architecture nor do I know exactly what would have to be changed specifically in gRPC-Java.

My naive assumption is that a similar approach like the one taken for aarch64 support might work:
#6441

[ejona86]

We tend to have these other architectures be user contributions because we can't test them. So if you contribute a change, at least we know it works for one user.

[kiwi1969]

Since sept 2020 grpcjava works on IBM JVM using IBMJSEE2 on S390x with pull #7422

Is the issue here now resolved?

[ejona86]

This issue is about protoc binaries for running the build on an s390x machine. With #7422 you can compile on another machine easily and deploy on s390x, but it is still annoying to run protoc as part of the build.

[ejona86]

Fixed by #9455