snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

examples/features/retry/README.md

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+# Retry
+
+This example shows how to enable and configure retry on gRPC clients.
+
+## Documentation
+
+[gRFC for client-side retry support](https://github.com/grpc/proposal/blob/master/A6-client-retries.md)
+
+## Try it
+
+This example includes a service implementation that fails requests three times with status
+code `Unavailable`, then passes the fourth.  The client is configured to make four retry attempts
+when receiving an `Unavailable` status code.
+
+First start the server:
+
+```bash
+go run server/main.go
+```
+
+Then run the client:
+
+```bash
+go run client/main.go
+```
+
+## Usage
+
+### Define your retry policy
+
+Retry is enabled via the service config, which can be provided by the name resolver or
+a DialOption (described below).  In the below config, we set retry policy for the
+"grpc.example.echo.Echo" method.
+
+MaxAttempts: how many times to attempt the RPC before failing.
+InitialBackoff, MaxBackoff, BackoffMultiplier: configures delay between attempts.
+RetryableStatusCodes: Retry only when receiving these status codes.
+
+```go
+        var retryPolicy = `{
+            "methodConfig": [{
+                // config per method or all methods under service
+                "name": [{"service": "grpc.examples.echo.Echo"}],
+
+                "retryPolicy": {
+                    "MaxAttempts": 4,
+                    "InitialBackoff": ".01s",
+                    "MaxBackoff": ".01s",
+                    "BackoffMultiplier": 1.0,
+                    // this value is grpc code
+                    "RetryableStatusCodes": [ "UNAVAILABLE" ]
+                }
+            }]
+        }`
+```
+
+### Providing the retry policy as a DialOption
+
+To use the above service config, pass it with `grpc.WithDefaultServiceConfig` to
+`grpc.NewClient`.
+
+```go
+conn, err := grpc.NewClient(target, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithDefaultServiceConfig(retryPolicy))
+```