google.golang.org/grpc@v1.62.1/README.md (about)

     1  # gRPC-Go
     2  
     3  [![GoDoc](https://pkg.go.dev/badge/google.golang.org/grpc)][API]
     4  [![GoReportCard](https://goreportcard.com/badge/grpc/grpc-go)](https://goreportcard.com/report/github.com/grpc/grpc-go)
     5  [![codecov](https://codecov.io/gh/grpc/grpc-go/graph/badge.svg)](https://codecov.io/gh/grpc/grpc-go)
     6  
     7  The [Go][] implementation of [gRPC][]: A high performance, open source, general
     8  RPC framework that puts mobile and HTTP/2 first. For more information see the
     9  [Go gRPC docs][], or jump directly into the [quick start][].
    10  
    11  ## Prerequisites
    12  
    13  - **[Go][]**: any one of the **three latest major** [releases][go-releases].
    14  
    15  ## Installation
    16  
    17  Simply add the following import to your code, and then `go [build|run|test]`
    18  will automatically fetch the necessary dependencies:
    19  
    20  
    21  ```go
    22  import "google.golang.org/grpc"
    23  ```
    24  
    25  > **Note:** If you are trying to access `grpc-go` from **China**, see the
    26  > [FAQ](#FAQ) below.
    27  
    28  ## Learn more
    29  
    30  - [Go gRPC docs][], which include a [quick start][] and [API
    31    reference][API] among other resources
    32  - [Low-level technical docs](Documentation) from this repository
    33  - [Performance benchmark][]
    34  - [Examples](examples)
    35  
    36  ## FAQ
    37  
    38  ### I/O Timeout Errors
    39  
    40  The `golang.org` domain may be blocked from some countries. `go get` usually
    41  produces an error like the following when this happens:
    42  
    43  ```console
    44  $ go get -u google.golang.org/grpc
    45  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 216.239.37.1:443: i/o timeout)
    46  ```
    47  
    48  To build Go code, there are several options:
    49  
    50  - Set up a VPN and access google.golang.org through that.
    51  
    52  - With Go module support: it is possible to use the `replace` feature of `go
    53    mod` to create aliases for golang.org packages.  In your project's directory:
    54  
    55    ```sh
    56    go mod edit -replace=google.golang.org/grpc=github.com/grpc/grpc-go@latest
    57    go mod tidy
    58    go mod vendor
    59    go build -mod=vendor
    60    ```
    61  
    62    Again, this will need to be done for all transitive dependencies hosted on
    63    golang.org as well. For details, refer to [golang/go issue
    64    #28652](https://github.com/golang/go/issues/28652).
    65  
    66  ### Compiling error, undefined: grpc.SupportPackageIsVersion
    67  
    68  Please update to the latest version of gRPC-Go using
    69  `go get google.golang.org/grpc`.
    70  
    71  ### How to turn on logging
    72  
    73  The default logger is controlled by environment variables. Turn everything on
    74  like this:
    75  
    76  ```console
    77  $ export GRPC_GO_LOG_VERBOSITY_LEVEL=99
    78  $ export GRPC_GO_LOG_SEVERITY_LEVEL=info
    79  ```
    80  
    81  ### The RPC failed with error `"code = Unavailable desc = transport is closing"`
    82  
    83  This error means the connection the RPC is using was closed, and there are many
    84  possible reasons, including:
    85   1. mis-configured transport credentials, connection failed on handshaking
    86   1. bytes disrupted, possibly by a proxy in between
    87   1. server shutdown
    88   1. Keepalive parameters caused connection shutdown, for example if you have
    89      configured your server to terminate connections regularly to [trigger DNS
    90      lookups](https://github.com/grpc/grpc-go/issues/3170#issuecomment-552517779).
    91      If this is the case, you may want to increase your
    92      [MaxConnectionAgeGrace](https://pkg.go.dev/google.golang.org/grpc/keepalive?tab=doc#ServerParameters),
    93      to allow longer RPC calls to finish.
    94  
    95  It can be tricky to debug this because the error happens on the client side but
    96  the root cause of the connection being closed is on the server side. Turn on
    97  logging on __both client and server__, and see if there are any transport
    98  errors.
    99  
   100  [API]: https://pkg.go.dev/google.golang.org/grpc
   101  [Go]: https://golang.org
   102  [Go module]: https://github.com/golang/go/wiki/Modules
   103  [gRPC]: https://grpc.io
   104  [Go gRPC docs]: https://grpc.io/docs/languages/go
   105  [Performance benchmark]: https://performance-dot-grpc-testing.appspot.com/explore?dashboard=5180705743044608
   106  [quick start]: https://grpc.io/docs/languages/go/quickstart
   107  [go-releases]: https://golang.org/doc/devel/release.html