feat: trigger breaker on underlying service timeout (#4112)

zrpc/internal/serverinterceptors/breakerinterceptor.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 
 	"github.com/zeromicro/go-zero/core/breaker"
+	"github.com/zeromicro/go-zero/core/errorx"
 	"github.com/zeromicro/go-zero/zrpc/internal/codes"
 	"google.golang.org/grpc"
 	gcodes "google.golang.org/grpc/codes"
@@ -13,11 +14,13 @@ import (
 
 // StreamBreakerInterceptor is an interceptor that acts as a circuit breaker.
 func StreamBreakerInterceptor(svr any, stream grpc.ServerStream, info *grpc.StreamServerInfo,
-	handler grpc.StreamHandler) (err error) {
+	handler grpc.StreamHandler) error {
 	breakerName := info.FullMethod
-	return breaker.DoWithAcceptable(breakerName, func() error {
+	err := breaker.DoWithAcceptable(breakerName, func() error {
 		return handler(svr, stream)
-	}, codes.Acceptable)
+	}, serverSideAcceptable)
+
+	return convertError(err)
 }
 
 // UnaryBreakerInterceptor is an interceptor that acts as a circuit breaker.
@@ -28,10 +31,28 @@ func UnaryBreakerInterceptor(ctx context.Context, req any, info *grpc.UnaryServe
 		var err error
 		resp, err = handler(ctx, req)
 		return err
-	}, codes.Acceptable)
-	if errors.Is(err, breaker.ErrServiceUnavailable) {
-		err = status.Error(gcodes.Unavailable, err.Error())
+	}, serverSideAcceptable)
+
+	return resp, convertError(err)
+}
+
+func convertError(err error) error {
+	if err == nil {
+		return nil
 	}
 
-	return resp, err
+	// we don't convert context.DeadlineExceeded to status error,
+	// because grpc will convert it and return to the client.
+	if errors.Is(err, breaker.ErrServiceUnavailable) {
+		return status.Error(gcodes.Unavailable, err.Error())
+	}
+
+	return err
+}
+
+func serverSideAcceptable(err error) bool {
+	if errorx.In(err, context.DeadlineExceeded, breaker.ErrServiceUnavailable) {
+		return false
+	}
+	return codes.Acceptable(err)
 }