# gRPC-Go

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The Go implementation of [gRPC](https://grpc.io/): A high performance, open source, general RPC framework that puts mobile and HTTP/2 first. For more information see the [gRPC Quick Start: Go](https://grpc.io/docs/quickstart/go.html) guide.

Installation
------------

To install this package, you need to install Go and setup your Go workspace on your computer. The simplest way to install the library is to run:

```
$ go get -u google.golang.org/grpc
```

Prerequisites
-------------

This requires Go 1.6 or later. Go 1.7 will be required soon.

Constraints
-----------
The grpc package should only depend on standard Go packages and a small number of exceptions. If your contribution introduces new dependencies which are NOT in the [list](http://godoc.org/google.golang.org/grpc?imports), you need a discussion with gRPC-Go authors and consultants.

Documentation
-------------
See [API documentation](https://godoc.org/google.golang.org/grpc) for package and API descriptions and find examples in the [examples directory](examples/).

Performance
-----------
See the current benchmarks for some of the languages supported in [this dashboard](https://performance-dot-grpc-testing.appspot.com/explore?dashboard=5652536396611584&widget=490377658&container=1286539696).

Status
------
General Availability [Google Cloud Platform Launch Stages](https://cloud.google.com/terms/launch-stages).

FAQ
---

#### Compiling error, undefined: grpc.SupportPackageIsVersion

Please update proto package, gRPC package and rebuild the proto files:
 - `go get -u github.com/golang/protobuf/{proto,protoc-gen-go}`
 - `go get -u google.golang.org/grpc`
 - `protoc --go_out=plugins=grpc:. *.proto`

#### How to turn on logging

The default logger is controlled by the environment variables. Turn everything
on by setting:

```
GRPC_GO_LOG_VERBOSITY_LEVEL=99 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:
 1. mis-configured transport credentials, connection failed on handshaking
 1. bytes disrupted, possibly by a proxy in between
 1. server shutdown

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.