The Go implementation of gRPC: A high performance, open source, general RPC framework that puts mobile and HTTP/2 first. For more information see the Go gRPC docs, or jump directly into the quick start.
Simply add the following import to your code, and then
will automatically fetch the necessary dependencies:
Note: If you are trying to access
grpc-gofrom China, see the FAQ below.
- Go gRPC docs, which include a quick start and API reference among other resources
- Low-level technical docs from this repository
- Performance benchmark
I/O Timeout Errors
golang.org domain may be blocked from some countries.
go get usually
produces an error like the following when this happens:
$ go get -u google.golang.org/grpc package google.golang.org/grpc: unrecognized import path "google.golang.org/grpc" (https fetch: Get https://google.golang.org/grpc?go-get=1: dial tcp 184.108.40.206:443: i/o timeout)
To build Go code, there are several options:
Set up a VPN and access google.golang.org through that.
With Go module support: it is possible to use the
go modto create aliases for golang.org packages. In your project's directory:
go mod edit -replace=google.golang.org/grpc=github.com/grpc/grpc-go@latest go mod tidy go mod vendor go build -mod=vendor
Again, this will need to be done for all transitive dependencies hosted on golang.org as well. For details, refer to golang/go issue #28652.
Compiling error, undefined: grpc.SupportPackageIsVersion
Please update to the latest version of gRPC-Go using
go get google.golang.org/grpc.
How to turn on logging
The default logger is controlled by environment variables. Turn everything on like this:
$ export GRPC_GO_LOG_VERBOSITY_LEVEL=99 $ export GRPC_GO_LOG_SEVERITY_LEVEL=info
The RPC failed with error
"code = Unavailable desc = transport is closing"
This error means the connection the RPC is using was closed, and there are many possible reasons, including:
- mis-configured transport credentials, connection failed on handshaking
- bytes disrupted, possibly by a proxy in between
- server shutdown
- Keepalive parameters caused connection shutdown, for example if you have configured your server to terminate connections regularly to trigger DNS lookups. If this is the case, you may want to increase your MaxConnectionAgeGrace, to allow longer RPC calls to finish.
It can be tricky to debug this because the error happens on the client side but the root cause of the connection being closed is on the server side. Turn on logging on both client and server, and see if there are any transport errors.