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Because of issues with glibc, using the `os/user` package can cause when calling `user.Current()`. Neither the Go maintainers or glibc developers could be bothered to fix it, so we have to work around it by calling the uid and gid functions directly. This is probably better because we don't actually use much of the data provided in the `user.User` struct. This required some refactoring to have better control over when the uid and gid are resolved. Rather than checking the current user on every connection, we now resolve it once at initialization. To test that this provided an improvement in performance, a benchmark was added. Unfortunately, this exposed a regression in the performance of unix sockets in Go when `(*UnixConn).File` is called. The underlying culprit of this performance regression is still at large. The following open issues describe the underlying problem in more detail: https://github.com/golang/go/issues/13470 https://sourceware.org/bugzilla/show_bug.cgi?id=19341 In better news, I now have an entire herd of shaved yaks. Signed-off-by: Stephen J Day <stephen.day@docker.com>
ttrpc
GRPC for low-memory environments.
The existing grpc-go project requires a lot of memory overhead for importing packages and at runtime. While this is great for many services with low density requirements, this can be a problem when running a large number of services on a single machine or on a machine with a small amount of memory.
Using the same GRPC definitions, this project reduces the binary size and
protocol overhead required. We do this by eliding the net/http, net/http2
and grpc package used by grpc replacing it with a lightweight framing
protocol. The result are smaller binaries that use less resident memory with
the same ease of use as GRPC.
Please note that while this project supports generating either end of the protocol, the generated service definitions will be incompatible with regular GRPC services, as they do not speak the same protocol.
Usage
Create a gogo vanity binary (see
cmd/protoc-gen-gogottrpc/main.go for an
example with the ttrpc plugin enabled.
It's recommended to use protobuild
to build the protobufs for this project, but this will work with protoc
directly, if required.
Differences from GRPC
- The protocol stack has been replaced with a lighter protocol that doesn't require http, http2 and tls.
- The client and server interface are identical whereas in GRPC there is a client and server interface that are different.
- The Go stdlib context package is used instead.
- No support for streams yet.
Status
Very new. YMMV.
TODO:
- Plumb error codes and GRPC status
- Remove use of any type and dependency on typeurl package
- Ensure that protocol can support streaming in the future
- Document protocol layout
- Add testing under concurrent load to ensure
- Verify connection error handling