限流,可以网络的基础设施进行配置实现,也可以在网关的地方进行限流,但服务本身的限流也不可或缺,因为当多副本时,一个副本故障,流量对于其他副本来说会提高,如果超过其承受请求量的范围,会引起服务连续崩塌,所以单服务本身最好也是要实现限流的。

在asp.net core项目中,可以引入AspNetCoreRateLimit进行限流处理。

可以通过如下方式引入NuGet包

Install-Package AspNetCoreRateLimit

Client限流

using AspNetCoreRateLimit;

var builder = WebApplication.CreateBuilder(args);
// 注入内存缓存服务
builder.Services.AddMemoryCache();
//加载ClientRateLimiting配置文件
builder.Services.Configure<ClientRateLimitOptions>(builder.Configuration.GetSection("ClientRateLimiting"));
//加载ClientRateLimitPolicies配置文件
builder.Services.Configure<ClientRateLimitPolicies>(builder.Configuration.GetSection("ClientRateLimitPolicies"));

// 注入限流内存缓存服务
builder.Services.AddInMemoryRateLimiting();
// 注入限流配置文件服务
builder.Services.AddSingleton<IRateLimitConfiguration, RateLimitConfiguration>();

var app = builder.Build();

//启用ClientRateLimitPolicies
var clientPolicyStore = app.Services.GetRequiredService<IClientPolicyStore>();
await clientPolicyStore.SeedAsync();
//使用Client限流中间件
app.UseClientRateLimiting();

app.MapGet("/test00", () =>
{
return "get test00 ok";
});

app.MapGet("/test01", () =>
{
return "get test01 ok";
});
app.MapGet("/test02", () =>
{
return "get test02 ok";
});
app.MapPost("/test02", () =>
{
return "post test02 ok";
});

app.Run();

appsetings.json

{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"AllowedHosts": "*",
"ClientRateLimiting": {
"EnableEndpointRateLimiting": false,
"StackBlockedRequests": false,
"ClientIdHeader": "X-ClientId",
"HttpStatusCode": 429,
"EndpointWhitelist": [ "get:/test00", "*:/test01" ],
"ClientWhitelist": [ "dev-id-1", "dev-id-2" ],
"GeneralRules": [
{
"Endpoint": "*",
"Period": "5s",
"Limit": 2
},
{
"Endpoint": "*",
"Period": "10s",
"Limit": 3
}
]
},
"ClientRateLimitPolicies": {
"ClientRules": [
{
"ClientId": "client-id-1",
"Rules": [
{
"Endpoint": "*",
"Period": "5s",
"Limit": 1
},
{
"Endpoint": "*",
"Period": "15m",
"Limit": 200
}
]
},
{
"ClientId": "client-id-2",
"Rules": [
{
"Endpoint": "*",
"Period": "1s",
"Limit": 5
},
{
"Endpoint": "*",
"Period": "15m",
"Limit": 150
},
{
"Endpoint": "*",
"Period": "12h",
"Limit": 500
}
]
}
]
}
}

配置说明:

EnableEndpointRateLimiting为false全部请求总次数超过阈值,即限流,EnableEndpointRateLimiting为true时,各个请求单次超过阈值即限流StackBlockedRequests为false时,如果前5s请求了2个成功,1个失败,那第6s后还可以请求一个成功,如果这StackBlockedRequests为true时,那第6s的请求是不能成功的,也就是带不带拒绝的请求

{
"Endpoint": "*",
"Period": "5s",
"Limit": 2
},
{
"Endpoint": "*",
"Period": "10s",
"Limit": 3
},

ClientIdHeader指定可以通过Header键为X-ClientId处理限流黑白名单ClientWhitelist值为dev-id-1,dev-id-2,指Header里X-ClientId只要是其中的值 ,就放行EndpointWhitelist不参与限流的终节点HttpStatusCode限流后返回的状态码

GeneralRules通用限流规则

ClientRateLimitPolicies 配置是专门为了对不同的X-ClientId进行不同的限流配置,这样可以有区别的来分配流程,而不是一概而论,可以说是ClientId的灰名单,有限流的访问

不但可以通过ClientID限流,还可以是客户请示Ip来限流,配置雷同。

IP限流

using AspNetCoreRateLimit;

var builder = WebApplication.CreateBuilder(args);
// 注入内存缓存服务
builder.Services.AddMemoryCache();


//加载IPRateLimiting配置文件
builder.Services.Configure<IpRateLimitOptions>(builder.Configuration.GetSection("IpRateLimiting"));

//加载IPRateLimitPolicies配置文件
builder.Services.Configure<IpRateLimitPolicies>(builder.Configuration.GetSection("IpRateLimitPolicies"));

// 注入限流内存缓存服务
builder.Services.AddInMemoryRateLimiting();
// 注入限流配置文件服务
builder.Services.AddSingleton<IRateLimitConfiguration, RateLimitConfiguration>();

var app = builder.Build();
//启用IPRateLimitPolicies
var ipPolicyStore = app.Services.GetRequiredService<IIpPolicyStore>();
await ipPolicyStore.SeedAsync();
//使用Ip限流中间件
app.UseIpRateLimiting();

app.MapGet("/test00", () =>
{
return "get test00 ok";
});

app.MapGet("/test01", () =>
{
return "get test01 ok";
});

app.MapGet("/test02", () =>
{
return "get test02 ok";
});
app.MapPost("/test02", () =>
{
return "post test02 ok";
});
app.MapGet("/test03", () =>
{
return "get test01 ok";
});
app.Run();

appsettings.json

{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"AllowedHosts": "*",
"IpRateLimiting": {
"EnableEndpointRateLimiting": false,
"StackBlockedRequests": false,
"RealIpHeader": "X-Real-IP",
"IpWhitelist": [ "127.0.0.1"],
"ClientIdHeader": "X-ClientId",
"HttpStatusCode": 429,
"EndpointWhitelist": [ "get:/test00", "*:/test01" ],
"ClientWhitelist": [ "dev-id-1", "dev-id-2" ],
"GeneralRules": [
{
"Endpoint": "*",
"Period": "5s",
"Limit": 2
},
{
"Endpoint": "*",
"Period": "10s",
"Limit": 3
}
]
},
"IpRateLimitPolicies": {
"IpRules": [
{
"Ip": "127.0.0.2",
"Rules": [
{
"Endpoint": "*",
"Period": "4s",
"Limit": 1
},
{
"Endpoint": "*",
"Period": "15m",
"Limit": 200
}
]
}
]
}
}

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.NET6之MiniAPI(二十一):限流_配置文件