요청 제한 미들웨어 구성

AddRateLimiter

builder.Services.AddRateLimiter(options =>
{
    options.RejectionStatusCode =
        StatusCodes.Status429TooManyRequests;
});

고정 구간 정책

options.AddFixedWindowLimiter("fixed", limiter =>
{
    limiter.PermitLimit = 100;
    limiter.Window = TimeSpan.FromMinutes(1);
    limiter.QueueProcessingOrder = QueueProcessingOrder.OldestFirst;
    limiter.QueueLimit = 0;
});

이동 구간 정책

options.AddSlidingWindowLimiter("sliding", limiter =>
{
    limiter.PermitLimit = 100;
    limiter.Window = TimeSpan.FromMinutes(1);
    limiter.SegmentsPerWindow = 6;
    limiter.QueueLimit = 0;
});

토큰 버킷 정책

options.AddTokenBucketLimiter("token", limiter =>
{
    limiter.TokenLimit = 100;
    limiter.TokensPerPeriod = 20;
    limiter.ReplenishmentPeriod = TimeSpan.FromSeconds(10);
    limiter.QueueLimit = 0;
});

동시성 정책

options.AddConcurrencyLimiter("concurrent", limiter =>
{
    limiter.PermitLimit = 5;
    limiter.QueueLimit = 10;
    limiter.QueueProcessingOrder = QueueProcessingOrder.OldestFirst;
});

미들웨어 추가

var app = builder.Build();

app.UseRateLimiter();

app.MapControllers();

RequireRateLimiting

app.MapGet("/search", () => Results.Ok())
   .RequireRateLimiting("token");

// Controller equivalent:
// [EnableRateLimiting("token")]

특정 엔드포인트에서 비활성화

app.MapGet("/health", () => Results.Ok())
   .DisableRateLimiting();

분할을 사용하는 전역 제한기

options.GlobalLimiter = PartitionedRateLimiter.Create<HttpContext, string>(
    context =>
    {
        var key = context.User.Identity?.Name
                  ?? context.Connection.RemoteIpAddress?.ToString()
                  ?? "anon";
        return RateLimitPartition.GetFixedWindowLimiter(key, _ =>
            new FixedWindowRateLimiterOptions
            {
                PermitLimit = 100,
                Window = TimeSpan.FromMinutes(1)
            });
    });

거부 응답 사용자 지정

options.OnRejected = async (context, token) =>
{
    if (context.Lease.TryGetMetadata(
            MetadataName.RetryAfter, out var retry))
        context.HttpContext.Response.Headers.RetryAfter =
            ((int)retry.TotalSeconds).ToString();
    await context.HttpContext.Response
        .WriteAsync("Rate limit exceeded.", token);
};

경로 그룹에 적용

var api = app.MapGroup("/api")
             .RequireRateLimiting("fixed");

api.MapGet("/products", () => Results.Ok());
api.MapGet("/orders", () => Results.Ok());

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