gRPC for .NET configuration
Note
This isn't the latest version of this article. For the current release, see the .NET 9 version of this article.
Warning
This version of ASP.NET Core is no longer supported. For more information, see the .NET and .NET Core Support Policy. For the current release, see the .NET 9 version of this article.
Important
This information relates to a pre-release product that may be substantially modified before it's commercially released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
For the current release, see the .NET 9 version of this article.
Configure services options
gRPC services are configured with AddGrpc
in Startup.cs
. Configuration options are in the Grpc.AspNetCore.Server
package.
The following table describes options for configuring gRPC services:
Option | Default Value | Description |
---|---|---|
MaxSendMessageSize |
null |
The maximum message size in bytes that can be sent from the server. Attempting to send a message that exceeds the configured maximum message size results in an exception. When set to null , the message size is unlimited. |
MaxReceiveMessageSize |
4 MB | The maximum message size in bytes that can be received by the server. If the server receives a message that exceeds this limit, it throws an exception. Increasing this value allows the server to receive larger messages, but can negatively impact memory consumption. When set to null , the message size is unlimited. |
EnableDetailedErrors |
false |
If true , detailed exception messages are returned to clients when an exception is thrown in a service method. The default is false . Setting EnableDetailedErrors to true can leak sensitive information. |
CompressionProviders |
gzip | A collection of compression providers used to compress and decompress messages. Custom compression providers can be created and added to the collection. The default configured providers support gzip compression. |
ResponseCompressionAlgorithm |
null |
The compression algorithm used to compress messages sent from the server. The algorithm must match a compression provider in CompressionProviders . For the algorithm to compress a response, the client must indicate it supports the algorithm by sending it in the grpc-accept-encoding header. |
ResponseCompressionLevel |
null |
The compress level used to compress messages sent from the server. |
Interceptors |
None | A collection of interceptors that are run with each gRPC call. Interceptors are run in the order they are registered. Globally configured interceptors are run before interceptors configured for a single service. Interceptors have a per-request lifetime by default. The interceptor constructor is called and parameters are resolved from dependency injection (DI). An interceptor type can also be registered with DI to override how it is created and its lifetime. Interceptors offer similar functionalities compared to ASP.NET Core middleware. For more information, see gRPC Interceptors vs. Middleware. |
IgnoreUnknownServices |
false |
If true , calls to unknown services and methods don't return an UNIMPLEMENTED status, and the request passes to the next registered middleware in ASP.NET Core. |
Options can be configured for all services by providing an options delegate to the AddGrpc
call in Startup.ConfigureServices
:
public void ConfigureServices(IServiceCollection services)
{
services.AddGrpc(options =>
{
options.EnableDetailedErrors = true;
options.MaxReceiveMessageSize = 2 * 1024 * 1024; // 2 MB
options.MaxSendMessageSize = 5 * 1024 * 1024; // 5 MB
});
}
Options for a single service override the global options provided in AddGrpc
and can be configured using AddServiceOptions<TService>
:
public void ConfigureServices(IServiceCollection services)
{
services.AddGrpc().AddServiceOptions<MyService>(options =>
{
options.MaxReceiveMessageSize = 2 * 1024 * 1024; // 2 MB
options.MaxSendMessageSize = 5 * 1024 * 1024; // 5 MB
});
}
Service interceptors have a per-request lifetime by default. Registering the interceptor type with DI overrides how an interceptor is created and its lifetime.
public void ConfigureServices(IServiceCollection services)
{
services.AddGrpc(options =>
{
options.Interceptors.Add<LoggingInterceptor>();
});
services.AddSingleton<LoggingInterceptor>();
}
ASP.NET Core server options
Grpc.AspNetCore.Server
is hosted by an ASP.NET Core web server. There are a number of options for ASP.NET Core servers, including Kestrel, IIS and HTTP.sys. Each server offers additional options for how HTTP requests are served.
The server used by an ASP.NET Core app is configured in app startup code. The default server is Kestrel.
For more information about the different servers and their configuration options, see:
- Kestrel web server in ASP.NET Core
- HTTP.sys web server implementation in ASP.NET Core
- Host ASP.NET Core on Windows with IIS
Configure client options
gRPC client configuration is set on GrpcChannelOptions
. Configuration options are in the Grpc.Net.Client
package.
The following table describes options for configuring gRPC channels:
Option | Default Value | Description |
---|---|---|
HttpHandler |
New instance | The HttpMessageHandler used to make gRPC calls. A client can be set to configure a custom HttpClientHandler or add additional handlers to the HTTP pipeline for gRPC calls. If no HttpMessageHandler is specified, a new HttpClientHandler instance is created for the channel with automatic disposal. |
HttpClient |
null |
The HttpClient used to make gRPC calls. This setting is an alternative to HttpHandler . |
DisposeHttpClient |
false |
If set to true and an HttpMessageHandler or HttpClient is specified, then either the HttpHandler or HttpClient , respectively, is disposed when the GrpcChannel is disposed. |
LoggerFactory |
null |
The LoggerFactory used by the client to log information about gRPC calls. A LoggerFactory instance can be resolved from dependency injection or created using LoggerFactory.Create . For examples of configuring logging, see Logging and diagnostics in gRPC on .NET. |
MaxSendMessageSize |
null |
The maximum message size in bytes that can be sent from the client. Attempting to send a message that exceeds the configured maximum message size results in an exception. When set to null , the message size is unlimited. |
MaxReceiveMessageSize |
4 MB | The maximum message size in bytes that can be received by the client. If the client receives a message that exceeds this limit, it throws an exception. Increasing this value allows the client to receive larger messages, but can negatively impact memory consumption. When set to null , the message size is unlimited. |
Credentials |
null |
A ChannelCredentials instance. Credentials are used to add authentication metadata to gRPC calls. |
CompressionProviders |
gzip | A collection of compression providers used to compress and decompress messages. Custom compression providers can be created and added to the collection. The default configured providers support gzip compression. |
ThrowOperationCanceledOnCancellation |
false |
If set to true , clients throw OperationCanceledException when a call is canceled or its deadline is exceeded. |
UnsafeUseInsecureChannelCallCredentials |
false |
If set to true , CallCredentials are applied to gRPC calls made by an insecure channel. Sending authentication headers over an insecure connection has security implications and shouldn't be done in production environments. |
MaxRetryAttempts |
5 | The maximum retry attempts. This value limits any retry and hedging attempt values specified in the service config. Setting this value alone doesn't enable retries. Retries are enabled in the service config, which can be done using ServiceConfig . A null value removes the maximum retry attempts limit. For more information about retries, see Transient fault handling with gRPC retries. |
MaxRetryBufferSize |
16 MB | The maximum buffer size in bytes that can be used to store sent messages when retrying or hedging calls. If the buffer limit is exceeded, then no more retry attempts are made and all hedging calls but one will be canceled. This limit is applied across all calls made using the channel. A null value removes the maximum retry buffer size limit. |
MaxRetryBufferPerCallSize |
1 MB | The maximum buffer size in bytes that can be used to store sent messages when retrying or hedging calls. If the buffer limit is exceeded, then no more retry attempts are made and all hedging calls but one will be canceled. This limit is applied to one call. A null value removes the maximum retry buffer size limit per call. |
ServiceConfig |
null |
The service config for a gRPC channel. A service config can be used to configure gRPC retries. |
The following code:
- Sets the maximum send and receive message size on the channel.
- Creates a client.
static async Task Main(string[] args)
{
var channel = GrpcChannel.ForAddress("https://localhost:5001", new GrpcChannelOptions
{
MaxReceiveMessageSize = 5 * 1024 * 1024, // 5 MB
MaxSendMessageSize = 2 * 1024 * 1024 // 2 MB
});
var client = new Greeter.GreeterClient(channel);
var reply = await client.SayHelloAsync(
new HelloRequest { Name = "GreeterClient" });
Console.WriteLine("Greeting: " + reply.Message);
}
Note that client interceptors aren't configured with GrpcChannelOptions
. Instead, client interceptors are configured using the Intercept
extension method with a channel. This extension method is in the Grpc.Core.Interceptors
namespace.
static async Task Main(string[] args)
{
var channel = GrpcChannel.ForAddress("https://localhost:5001");
var callInvoker = channel.Intercept(new LoggingInterceptor());
var client = new Greeter.GreeterClient(callInvoker);
var reply = await client.SayHelloAsync(
new HelloRequest { Name = "GreeterClient" });
Console.WriteLine("Greeting: " + reply.Message);
}
System.Net handler options
Grpc.Net.Client
uses a HTTP transport derived from HttpMessageHandler
to make HTTP requests. Each handler offers additional options for how HTTP requests are made.
The handler is configured on a channel and can be overridden by setting GrpcChannelOptions.HttpHandler
. .NET Core 3 and .NET 5 or later uses SocketsHttpHandler by default. gRPC client apps on .NET Framework should configure WinHttpHandler.
For more information about the different handlers and their configuration options, see: