gRPC

API-History

SOAP

• Ursprünglich die Abkürzung für Simple Object Access Protocol.
• Service- und Datendefinitionen werden
  als XML (WSDL / XSD) bereitgestellt.
• Datenübertragung erfolgt als XML über HTTP 1.1 und POST.
• .NET / C# Implementierungen (legacy):
  • ASMX-Webservices (ab .NET Framework 1.0)
  • WCF mit HTTP-Binding (ab .NET Framework 3.0)

REST

• Abkürzung für Representational State Transfer.
• Programmierparadigma für verteilte Systeme, insbesondere Webservices (R. Fielding).
• Übertragung erfolgt per HTTP 1.1 in verschiedenen Formaten, meist JSON.
• Prinzipien: Client-Server, Zustandslosigkeit, Operationen, Adressierbarkeit und Ressourcen.

• L. Richardson entwickelte das Maturity Model, um den Reifegrad der API zu beschreiben - Ziel sind RESTful Services.
• Erweiterungen wie Swagger/OpenAPI bieten API-Beschreibungen an.

Keyfacts

• gRPC = gRPC Remote Procedure Call
• Freies, Open-Source Universal RPC-Framework von Google
• Nutzung von HTTP/2 (für die Verbindung)
  und Protocol Buffers (für Definition / Serialisierung).
• gRPC ist ein Bestandteil des Ökosystems der CNCF.
• Es bietet hohe Leistung, Sprachunabhängigkeit und Effizienz.
• Es kann um Authentifizierung, Lastenausgleich, Protokollierung und Überwachung erweitert werden.

Sprachunterstützung

HTTP/2

• Von Google entwickeltes Vorläuferprotokoll SPDY
• Im Mai 2015 von der IETF als Nachfolger
  von HTTP 1.1 freigegeben (RFC 7540)
• Weitreichende Datenkompression
• Schnelle TLS-Verschlüsselung (empfohlen)
• Binär kodierte Übertragung der Inhalte
• Zusammenfassung mehrerer Anfragen (Multiplexing)
  über eine TCP-Verbindung
• Serverinitiierte Datenübertragung (Push-Verfahren)

Überblick

Imports

import "google/protobuf/struct.proto";
import "google/protobuf/timestamp.proto";
import "google/protobuf/wrappers.proto";
 
import "grp-demo-apps/helpers.proto";
import "google/protobuf/struct.proto";
import "google/protobuf/timestamp.proto";
import "google/protobuf/wrappers.proto";
 
import "grp-demo-apps/helpers.proto";

File options

option java_multiple_files = true;
option java_package = "my.java.example";

option csharp_namespace = "MyDemoService.Contract";

Servicedefinition

service DemoServices {
    rpc GetDemo (GetDemoRequest)  returns (GetDemoResponse); 
    rpc SetDemo (SetDemoRequest)  returns (google.protobuf.Empty); 
}
service DemoServices {
    rpc GetDemo (GetDemoRequest)  returns (GetDemoResponse); 
    rpc SetDemo (SetDemoRequest)  returns (google.protobuf.Empty); 
}

Datenstrukturen

Indexierung

message MyDemoMessage {
  int32 id = 1;
  bool is_valid = 2;
  Dummy dummy = 5;
}

Skalare Datentypen

message MyDemoMessage {
  string name = 1;
  string frist_name = 2;
  google.protobuf.Timestamp create_on = 3;
}

Enumeration

enum DemoEnum {
 NONE = 0;
 OPTION1 = 1;
 OPTION2 = 2;
}

Listen

message MyListMessage {
  repeated Dummy dummy = 5;
}

Verschachtelte Typen / Wiederverwendung

message MyDemoMessage {
 message Dummy {   
  int64 prop1 = 1;
  bool  prop2 = 2;
 }
 Dummy dummy1 = 1;
 Dummy dummy2 = 2;
}

message MyDemoMessage {
 Dummy dummy1 = 1;
 Dummy dummy2 = 2;
}
 
message Dummy {
 int64 prop1 = 1;
 bool  prop2 = 2;
}

Überblick

Visual Studio Integration

Client-Integration

<Project Sdk="Microsoft.NET.Sdk">
  <ItemGroup>
    <Protobuf Include="..\Proto\my-contract.proto" GrpcServices="Client"
       Link="Protos\my-contract.proto" />
    <PackageReference Include="Google.Protobuf" Version="3.25.2" />
    <PackageReference Include="Grpc.Net.Client" Version="2.60.0" />
    <PackageReference Include="Grpc.Tools" Version="2.60.0" PrivateAssets="All" />
  </ItemGroup>
</Project>

Server-Integration

<Project Sdk="Microsoft.NET.Sdk">
  <ItemGroup>
    <Protobuf Include="..\Proto\my-contract.proto" GrpcServices="Server"
       Link="Protos\my-contract.proto" />
    <PackageReference Include="Grpc.AspNetCore" Version="2.60.0" />
    </ItemGroup>
</Project>

Implementierung Service

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddGrpc();
var app = builder.Build();
app.MapGrpcService<GRPC-SERVICE-CLASS>();
app.Run();
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddGrpc();
var app = builder.Build();
app.MapGrpcService<GRPC-SERVICE-CLASS>();
app.Run();
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddGrpc();
var app = builder.Build();
app.MapGrpcService<GRPC-SERVICE-CLASS>();
app.Run();

Errorhandling

public override Task<GetDemoResponse>GetDemo(GetDemoRequest request, ServerCallContext context)
{
  ...
  context.Status = new Status(StatusCode.InvalidArgument, "something was wrong");
  ...
}
public override Task<GetDemoResponse>GetDemo(GetDemoRequest request, ServerCallContext context)
{
  ...
  context.Status = new Status(StatusCode.InvalidArgument, "something was wrong");
  ...
}

Verwendung Client

Workaround .NET Core 3.1

AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);

Dependency Injection

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddGrpcClient<Demo.DemoClient>("demo", o =>{ o.Address = ...});
...
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddGrpcClient<Demo.DemoClient>("demo", o =>{ o.Address = ...});
...

public class DummyController : Controller
{
  private Demo.DemoClient _client;
  public DummyController(GrpcClientFactory grpcClientFactory)
  {
    _client = grpcClientFactory.CreateClient<Demo.DemoClient>("demo");
  }
}
public class DummyController : Controller
{
  private Demo.DemoClient _client;
  public DummyController(GrpcClientFactory grpcClientFactory)
  {
    _client = grpcClientFactory.CreateClient<Demo.DemoClient>("demo");
  }
}

Monitoring

OpenTelemetry

• Distributed Traces
  • Ermittlung und Weitergabe des Tracing-Context im Client und Service
  • Nuget GrpcNetClient (beta) / AspNetCore
• Metriken
  • Ermittlung Anzahl der Aufrufe (inkl. Status) und Ausführungsdauer
  • Aktuell nur Unterstützung für unterliegende HTTP-Verbindung
  • Nuget Http-Client / AspNetCore
  • Detailierte Metriken per Custom-Interceptor oder Community

prometheus-net

"Kestrel": {
 "Endpoints": {
  "Http1": {
   "Url": "http://0.0.0.0:5001",
   "Protocols": "Http1"
  },
  "Http2": {
   "Url": "http://0.0.0.0:5002",
   "Protocols": "Http2"
  }
 }
}

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.UseGrpcMetrics();
app.UseEndpoints(endpoints =>
  { ...
    endpoints.MapMetrics();     
    ...
  }
app.Run();
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.UseGrpcMetrics();
app.UseEndpoints(endpoints =>
  { ...
    endpoints.MapMetrics();     
    ...
  }
app.Run();
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.UseGrpcMetrics();
app.UseEndpoints(endpoints =>
  { ...
    endpoints.MapMetrics();     
    ...
  }
app.Run();

BloomRPC (Archived)

• GUI Client für gRPC Services
• Entwickelt mit HTML, CSS und React
• LGPL-3.0 License
• Cross-Platfrom durch Electron
• Import von Protobuf-Definitionen
• Unary Calls und Streaming
• Native gRPC und gRPC Web
• TLS und non-TLS-Verbindungen

Postman

• Unterstützung seit 2022
• Unary Calls und Streaming (Client, Server, Bidirectional)
• Import Service-Definition per proto-Datei oder Server Reflection
• Erzeugung Beispielanfragen als JSON
• Empfang und Versand von Metadaten z.B. Header
• Verschlüsselter und unverschlüsselter Datenverkehr
• Variableninterpolation mithilfe von Umgebungen
• Importieren, bearbeiten und prüfen von Protobuf-Definitionen
  mit Syntax Highlighting und Autovervollständigung
• Authentifizierung mit Basic Auth, Bearer Token und API-Key

Überblick

Arten

• Client-Streaming
• Server-Streaming
• Bidirectional-Streaming

Contract

Client-Streaming

service ClientStreamServices {
 rpc SendPartDemo (stream SendPartDemoRequest)  returns (SendPartDemoResponse); 
}

Server-Streaming

service ServerStreamServices {
 rpc ReceivePartDemo (ReceivePartDemoRequest)  returns (stream ReceivePartDemoResponse); 
}

Bidirectional-Streaming

service BidirectionalStreamServices {
 rpc MultipartDemo (stream MultipartC2SMessage)  returns (stream MultipartS2CMessage); 
}

Implementierung

Client-Streaming

public override async Task<SendPartDemoResponse> SendPartDemo(
    IAsyncStreamReader<SendPartDemoRequest> requestStream, ServerCallContext context)
{
  ...
  await foreach (var request in requestStream.ReadAllAsync())
  {
    ...
  }
  return new SendPartDemoResponse();
}
public override async Task<SendPartDemoResponse> SendPartDemo(
    IAsyncStreamReader<SendPartDemoRequest> requestStream, ServerCallContext context)
{
  ...
  await foreach (var request in requestStream.ReadAllAsync())
  {
    ...
  }
  return new SendPartDemoResponse();
}
public override async Task<SendPartDemoResponse> SendPartDemo(
    IAsyncStreamReader<SendPartDemoRequest> requestStream, ServerCallContext context)
{
  ...
  await foreach (var request in requestStream.ReadAllAsync())
  {
    ...
  }
  return new SendPartDemoResponse();
}

using (var streamingCall = client.SendPartDemo())
{
  ...
  await streamingCall.RequestStream.WriteAsync(new SendPartDemoRequest { ... })
  ...
  await streamingCall.RequestStream.CompleteAsync();
  var result = await streamingCall.ResponseAsync;
}
using (var streamingCall = client.SendPartDemo())
{
  ...
  await streamingCall.RequestStream.WriteAsync(new SendPartDemoRequest { ... })
  ...
  await streamingCall.RequestStream.CompleteAsync();
  var result = await streamingCall.ResponseAsync;
}
using (var streamingCall = client.SendPartDemo())
{
  ...
  await streamingCall.RequestStream.WriteAsync(new SendPartDemoRequest { ... })
  ...
  await streamingCall.RequestStream.CompleteAsync();
  var result = await streamingCall.ResponseAsync;
}
using (var streamingCall = client.SendPartDemo())
{
  ...
  await streamingCall.RequestStream.WriteAsync(new SendPartDemoRequest { ... })
  ...
  await streamingCall.RequestStream.CompleteAsync();
  var result = await streamingCall.ResponseAsync;
}

Server-Streaming

  public override async Task ReceivePartDemo( 
      ReceivePartDemoRequest request,
      IServerStreamWriter<ReceivePartDemoResponse> responseStream, ServerCallContext context)
{
  ...
  await responseStream.WriteAsync(new ReceivePartDemoResponse { ... });
  ...
}
  public override async Task ReceivePartDemo( 
      ReceivePartDemoRequest request,
      IServerStreamWriter<ReceivePartDemoResponse> responseStream, ServerCallContext context)
{
  ...
  await responseStream.WriteAsync(new ReceivePartDemoResponse { ... });
  ...
}

using (var streamingCall = client.ReceivePartDemo())
{
  ...
  await foreach (var response in streamingCall.ResponseStream.ReadAllAsync())
  {
    ...
  }
}
using (var streamingCall = client.ReceivePartDemo())
{
  ...
  await foreach (var response in streamingCall.ResponseStream.ReadAllAsync())
  {
    ...
  }
}

Bidirectional-Streaming

  public override async Task MultipartDemo( 
    IAsyncStreamReader<MultipartC2SMessage> requestStream,
    IServerStreamWriter<MultipartS2CMessage> responseStream, ServerCallContext context)
{
  var taskRead = readAsync(requestStream, context);
  var taskWrite = WriteAsync(responseStream, context);
  await Task.WhenAll(taskRead,taskWrite);
}
  public override async Task MultipartDemo( 
    IAsyncStreamReader<MultipartC2SMessage> requestStream,
    IServerStreamWriter<MultipartS2CMessage> responseStream, ServerCallContext context)
{
  var taskRead = readAsync(requestStream, context);
  var taskWrite = WriteAsync(responseStream, context);
  await Task.WhenAll(taskRead,taskWrite);
}
  public override async Task MultipartDemo( 
    IAsyncStreamReader<MultipartC2SMessage> requestStream,
    IServerStreamWriter<MultipartS2CMessage> responseStream, ServerCallContext context)
{
  var taskRead = readAsync(requestStream, context);
  var taskWrite = WriteAsync(responseStream, context);
  await Task.WhenAll(taskRead,taskWrite);
}
  public override async Task MultipartDemo( 
    IAsyncStreamReader<MultipartC2SMessage> requestStream,
    IServerStreamWriter<MultipartS2CMessage> responseStream, ServerCallContext context)
{
  var taskRead = readAsync(requestStream, context);
  var taskWrite = WriteAsync(responseStream, context);
  await Task.WhenAll(taskRead,taskWrite);
}

 using (var streamingCall = client.MultipartDemo())
{
  var sendTask = SendMessage(streamingCall);
  var receiveTask = ReceiveMessage(streamingCall);
  await Task.WhenAll(sendTask, receiveTask);
}
 using (var streamingCall = client.MultipartDemo())
{
  var sendTask = SendMessage(streamingCall);
  var receiveTask = ReceiveMessage(streamingCall);
  await Task.WhenAll(sendTask, receiveTask);
}
 using (var streamingCall = client.MultipartDemo())
{
  var sendTask = SendMessage(streamingCall);
  var receiveTask = ReceiveMessage(streamingCall);
  await Task.WhenAll(sendTask, receiveTask);
}
 using (var streamingCall = client.MultipartDemo())
{
  var sendTask = SendMessage(streamingCall);
  var receiveTask = ReceiveMessage(streamingCall);
  await Task.WhenAll(sendTask, receiveTask);
}

Überblick

Client-Zertifikaten

Client

X509Certificate2 certificate =  LoadClientCertificate(...)
var httpClienthandler = new HttpClientHandler();
httpClienthandler.ClientCertificates.Add(certificate);
var httpClient = new HttpClient(handler); 
var options = new GrpcChannelOptions {  HttpClient = httpClient };
var channel = GrpcChannel.ForAddress(serviceUrl, opt);
var client = new AuthDemoServices.AuthDemoServicesClient(channel);
X509Certificate2 certificate =  LoadClientCertificate(...)
var httpClienthandler = new HttpClientHandler();
httpClienthandler.ClientCertificates.Add(certificate);
var httpClient = new HttpClient(handler); 
var options = new GrpcChannelOptions {  HttpClient = httpClient };
var channel = GrpcChannel.ForAddress(serviceUrl, opt);
var client = new AuthDemoServices.AuthDemoServicesClient(channel);
X509Certificate2 certificate =  LoadClientCertificate(...)
var httpClienthandler = new HttpClientHandler();
httpClienthandler.ClientCertificates.Add(certificate);
var httpClient = new HttpClient(handler); 
var options = new GrpcChannelOptions {  HttpClient = httpClient };
var channel = GrpcChannel.ForAddress(serviceUrl, opt);
var client = new AuthDemoServices.AuthDemoServicesClient(channel);
X509Certificate2 certificate =  LoadClientCertificate(...)
var httpClienthandler = new HttpClientHandler();
httpClienthandler.ClientCertificates.Add(certificate);
var httpClient = new HttpClient(handler); 
var options = new GrpcChannelOptions {  HttpClient = httpClient };
var channel = GrpcChannel.ForAddress(serviceUrl, opt);
var client = new AuthDemoServices.AuthDemoServicesClient(channel);

Service

[Authorize(AuthenticationSchemes = CertificateAuthenticationDefaults.AuthenticationScheme)]
public class AuthDemoServices : AuthDemoServices.AuthDemoServicesBase
{
    ...
}

Kestrel

var builder = WebApplication.CreateBuilder(args);
builder.WebHost.ConfigureKestrel(opt =>  {
  X509Certificate2 certificate = LoadServerCertificate(...);
  opt.ConfigureHttpsDefaults(d =>  {
    d.ClientCertificateMode = ClientCertificateMode.RequireCertificate;
    d.CheckCertificateRevocation = false;
    d.ServerCertificate = certificate;
    });
});
var builder = WebApplication.CreateBuilder(args);
builder.WebHost.ConfigureKestrel(opt =>  {
  X509Certificate2 certificate = LoadServerCertificate(...);
  opt.ConfigureHttpsDefaults(d =>  {
    d.ClientCertificateMode = ClientCertificateMode.RequireCertificate;
    d.CheckCertificateRevocation = false;
    d.ServerCertificate = certificate;
    });
});
var builder = WebApplication.CreateBuilder(args);
builder.WebHost.ConfigureKestrel(opt =>  {
  X509Certificate2 certificate = LoadServerCertificate(...);
  opt.ConfigureHttpsDefaults(d =>  {
    d.ClientCertificateMode = ClientCertificateMode.RequireCertificate;
    d.CheckCertificateRevocation = false;
    d.ServerCertificate = certificate;
    });
});
var builder = WebApplication.CreateBuilder(args);
builder.WebHost.ConfigureKestrel(opt =>  {
  X509Certificate2 certificate = LoadServerCertificate(...);
  opt.ConfigureHttpsDefaults(d =>  {
    d.ClientCertificateMode = ClientCertificateMode.RequireCertificate;
    d.CheckCertificateRevocation = false;
    d.ServerCertificate = certificate;
    });
});
var builder = WebApplication.CreateBuilder(args);
builder.WebHost.ConfigureKestrel(opt =>  {
  X509Certificate2 certificate = LoadServerCertificate(...);
  opt.ConfigureHttpsDefaults(d =>  {
    d.ClientCertificateMode = ClientCertificateMode.RequireCertificate;
    d.CheckCertificateRevocation = false;
    d.ServerCertificate = certificate;
    });
});

Startup

...
var app = builder.Build();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.MapGrpcService<GRPC-SERVICE-CLASS>();
...
...
var app = builder.Build();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.MapGrpcService<GRPC-SERVICE-CLASS>();
...
...
var app = builder.Build();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.MapGrpcService<GRPC-SERVICE-CLASS>();
...
...
var app = builder.Build();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.MapGrpcService<GRPC-SERVICE-CLASS>();
...
...
var app = builder.Build();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.MapGrpcService<GRPC-SERVICE-CLASS>();
...

JWT-Token / OAUTH

Server Reflection

• Liefert Metadaten zum gRPC-Service ähnlich wie OpenAPI.
• Ermöglicht Aufrufe ohne Zugriff auf den Proto-Contract.
• Unterstützung via Nuget-Paket Grpc.AspNetCore.Server.Reflection .
• Integration in die ASP.NET-Pipeline.
• Client-Tools: Postman , gRPC WebUI , grpcurl

WebApplicationBuilder builder = ...
builder.Services.AddGrpc();
builder.Service.AddGrpcReflection();
 
IEndpointRouteBuilder app = builder.Build();
app.MapGrpcService<...>
app.MapGrpcReflectionService();
WebApplicationBuilder builder = ...
builder.Services.AddGrpc();
builder.Service.AddGrpcReflection();
 
IEndpointRouteBuilder app = builder.Build();
app.MapGrpcService<...>
app.MapGrpcReflectionService();
WebApplicationBuilder builder = ...
builder.Services.AddGrpc();
builder.Service.AddGrpcReflection();
 
IEndpointRouteBuilder app = builder.Build();
app.MapGrpcService<...>
app.MapGrpcReflectionService();
WebApplicationBuilder builder = ...
builder.Services.AddGrpc();
builder.Service.AddGrpcReflection();
 
IEndpointRouteBuilder app = builder.Build();
app.MapGrpcService<...>
app.MapGrpcReflectionService();
WebApplicationBuilder builder = ...
builder.Services.AddGrpc();
builder.Service.AddGrpcReflection();
 
IEndpointRouteBuilder app = builder.Build();
app.MapGrpcService<...>
app.MapGrpcReflectionService();

Json Transcode

• Erweiterung für ASP.NET Core gRPC.
• Ersatz für gRPC HTTP API (experimentell).
• Gleichzeitige Bereitstellung von gRPC und RESTful JSON API.
• Nuget-Paket Microsoft.AspNetCore.Grpc.JsonTranscoding
• Unterstützung für HTTP-Verben (GET, POST, PUT ...).
• Annotationen für Route-Parameter und Query-Parameter.

Service / Middleware

WebApplicationBuilder builder = ...
builder.Services.AddGrpc().AddJsonTranscoding();
...
WebApplicationBuilder builder = ...
builder.Services.AddGrpc().AddJsonTranscoding();
...

Contract

...
import "google/api/annotations.proto";
service OrderService {
  rpc GetOrderById (GetOrderByIdRequest) returns (GetOrderResponse){
    option (google.api.http) = { 
        get: "/v1/orders/{id}"
    };
  };
}
message GetOrderByIdRequest {  string id = 1;  }
message GetOrderResponse {  string id = 1;  ...}

Kestrel

• RESTful-API sollte neben HTTP 2 per HTTP 1.1 erreichbar sein
• Bereitstellung über getrennten Port oder Multiprotocol-Port

"Kestrel": {
        "Endpoints": {
          "Http1": {
            "Url": "http://0.0.0.0:5001",
            "Protocols": "Http1"
          },
          "Http2": {
            "Url": "http://0.0.0.0:5002",
            "Protocols": "Http2"
          }
        }
      }

"Kestrel": {
    "EndpointDefaults": {
      "Protocols": "Http1AndHttp2"
    }
  }

OpenAPI

Performance

• Kestrel HTTP/2 (Architektur)
  • Wechsel von Lock zu IQ (Queue).
  • Verbesserung von gleichzeitigen Operationen u.a. Streaming.
  • Reduzierung des Ressourcenbedarfs.
• gRPC Upload Geschwindigkeit
  • Integrierter größerer Cache.
  • Bis zu 6x schnellere Übertragung größerer Dateien.
• gRPC Download Geschwindigkeit
  • HttpClient skaliert Empfangspufferfenster dynamisch

Clientseitigen Lastausgleich

• Verbessere Leistung (keine Proxy, weniger Netzwerk-Hops /
• Einfachere Anwendungsarchitektur (keine Konfiguration für Proxy)
• Discover Endpunkte (DNS, Statisch, Custom)
• Load Balance Mechanismen (Pick first, Round robin, Custom)

var channel = GrpcChannel.ForAddress("dns:///grpc.service.fqdn",
 new GrpcChannelOptions
  {
   Credentials = ChannelCredentials.Insecure,
   ServiceConfig = new ServiceConfig { LoadBalancingConfigs = { new RoundRobinConfig() } }
  });
var client = new MyDemo.DemoClient(channel);
var channel = GrpcChannel.ForAddress("dns:///grpc.service.fqdn",
 new GrpcChannelOptions
  {
   Credentials = ChannelCredentials.Insecure,
   ServiceConfig = new ServiceConfig { LoadBalancingConfigs = { new RoundRobinConfig() } }
  });
var client = new MyDemo.DemoClient(channel);
var channel = GrpcChannel.ForAddress("dns:///grpc.service.fqdn",
 new GrpcChannelOptions
  {
   Credentials = ChannelCredentials.Insecure,
   ServiceConfig = new ServiceConfig { LoadBalancingConfigs = { new RoundRobinConfig() } }
  });
var client = new MyDemo.DemoClient(channel);
var channel = GrpcChannel.ForAddress("dns:///grpc.service.fqdn",
 new GrpcChannelOptions
  {
   Credentials = ChannelCredentials.Insecure,
   ServiceConfig = new ServiceConfig { LoadBalancingConfigs = { new RoundRobinConfig() } }
  });
var client = new MyDemo.DemoClient(channel);

Transiente Fehlerbehandlung

• Kurzfristiger Verlust der Netzwerkverbindung
• Zeitweise Nichtverfügbarkeit
• Timeout durch Serverlast

Standard

Mit Wiederholung(en)

var mCfg = new MethodConfig{
  Names = { MethodName.Default },
  RetryPolicy = new RetryPolicy {
    MaxAttempts = 5,
    InitialBackoff = TimeSpan.FromSeconds(1),
    MaxBackoff = TimeSpan.FromSeconds(5),
    BackoffMultiplier = 1.5,
    RetryableStatusCodes = { StatusCode.Unavailable }
  }
};
var channel = GrpcChannel.ForAddress(
  "https://grpc.service.fqdn:5001",
    new GrpcChannelOptions { ServiceConfig =
      new ServiceConfig { MethodConfigs = { mCfg } }  });
var mCfg = new MethodConfig{
  Names = { MethodName.Default },
  RetryPolicy = new RetryPolicy {
    MaxAttempts = 5,
    InitialBackoff = TimeSpan.FromSeconds(1),
    MaxBackoff = TimeSpan.FromSeconds(5),
    BackoffMultiplier = 1.5,
    RetryableStatusCodes = { StatusCode.Unavailable }
  }
};
var channel = GrpcChannel.ForAddress(
  "https://grpc.service.fqdn:5001",
    new GrpcChannelOptions { ServiceConfig =
      new ServiceConfig { MethodConfigs = { mCfg } }  });
var mCfg = new MethodConfig{
  Names = { MethodName.Default },
  RetryPolicy = new RetryPolicy {
    MaxAttempts = 5,
    InitialBackoff = TimeSpan.FromSeconds(1),
    MaxBackoff = TimeSpan.FromSeconds(5),
    BackoffMultiplier = 1.5,
    RetryableStatusCodes = { StatusCode.Unavailable }
  }
};
var channel = GrpcChannel.ForAddress(
  "https://grpc.service.fqdn:5001",
    new GrpcChannelOptions { ServiceConfig =
      new ServiceConfig { MethodConfigs = { mCfg } }  });
var mCfg = new MethodConfig{
  Names = { MethodName.Default },
  RetryPolicy = new RetryPolicy {
    MaxAttempts = 5,
    InitialBackoff = TimeSpan.FromSeconds(1),
    MaxBackoff = TimeSpan.FromSeconds(5),
    BackoffMultiplier = 1.5,
    RetryableStatusCodes = { StatusCode.Unavailable }
  }
};
var channel = GrpcChannel.ForAddress(
  "https://grpc.service.fqdn:5001",
    new GrpcChannelOptions { ServiceConfig =
      new ServiceConfig { MethodConfigs = { mCfg } }  });
var mCfg = new MethodConfig{
  Names = { MethodName.Default },
  RetryPolicy = new RetryPolicy {
    MaxAttempts = 5,
    InitialBackoff = TimeSpan.FromSeconds(1),
    MaxBackoff = TimeSpan.FromSeconds(5),
    BackoffMultiplier = 1.5,
    RetryableStatusCodes = { StatusCode.Unavailable }
  }
};
var channel = GrpcChannel.ForAddress(
  "https://grpc.service.fqdn:5001",
    new GrpcChannelOptions { ServiceConfig =
      new ServiceConfig { MethodConfigs = { mCfg } }  });
var mCfg = new MethodConfig{
  Names = { MethodName.Default },
  RetryPolicy = new RetryPolicy {
    MaxAttempts = 5,
    InitialBackoff = TimeSpan.FromSeconds(1),
    MaxBackoff = TimeSpan.FromSeconds(5),
    BackoffMultiplier = 1.5,
    RetryableStatusCodes = { StatusCode.Unavailable }
  }
};
var channel = GrpcChannel.ForAddress(
  "https://grpc.service.fqdn:5001",
    new GrpcChannelOptions { ServiceConfig =
      new ServiceConfig { MethodConfigs = { mCfg } }  });
var mCfg = new MethodConfig{
  Names = { MethodName.Default },
  RetryPolicy = new RetryPolicy {
    MaxAttempts = 5,
    InitialBackoff = TimeSpan.FromSeconds(1),
    MaxBackoff = TimeSpan.FromSeconds(5),
    BackoffMultiplier = 1.5,
    RetryableStatusCodes = { StatusCode.Unavailable }
  }
};
var channel = GrpcChannel.ForAddress(
  "https://grpc.service.fqdn:5001",
    new GrpcChannelOptions { ServiceConfig =
      new ServiceConfig { MethodConfigs = { mCfg } }  });