Memory surge during load testing

[jinzaz]

Describe the bug

When I created an empty Web API Project and only added the reverse proxy service, and then used JMeter for load testing, I found a surge in memory. Below was the stack information monitored using dotnet dump and dotnet counters. I suspected that Jeeter was using keep-alive, but I added the app UseRequestTimeouts(); There will still be these phenomena, and I don't know what causes them

Further technical details

• yarp.reverse-proxy version 2.2.0-preview.1.24266.1
• linux docker contianer
• net 8.0

[MihaZupan]

Was the memory dump screenshot you shared taken after all the requests already completed?

Also just in case, can you share how you're using YARP (e.g. config file) / whether and how you're using the IHttpForwarder directly.

[jinzaz]

yeah this dump was after all the requests already completed!，this is my YARP config

  "ReverseProxy": {
    "Routes": {
      "basic-apiservice": {
        "Match": {
          "Methods": null,
          "Hosts": null,
          "Path": "/xxx/xxxx/{**catch-all}",
          "QueryParameters": null,
          "Headers": null
        },
        "ClusterId": "basic-apiservice",
        "AuthorizationPolicy": null,
        "RateLimiterPolicy": null,
        "Timeout": "00:00:20",
        "CorsPolicy": null,
        "Metadata": null,
        "Transforms": [
          {
            "PathRemovePrefix": "/xxxx/xxxx"
          }
        ]
      }
    },
    "Clusters": {
      "basic-apiservice": {
        "LoadBalancingPolicy": null,
        "SessionAffinity": null,
        "HealthCheck": null,
        "HttpClient": {
          "EnableMultipleHttp2Connections": true
        },
        "HttpRequest": {
          "AllowResponseBuffering": "false"
        },
        "Destinations": {
          "basic-apiservice/destination1": {
            "Address": "http://xxxx",
            "Health": "http://xxxxxx",
            "Metadata": null,
            "Host": null
          }
        },
        "Metadata": null
      }
    }
  }

I seem to have found a solution， I seem to have found the cause of the problem, partly due to the PinnedBlockMemoryPool in aspnetcore when the container memory is not restricted. This is similar to this problem ，https://github.com/dotnet/aspnetcore/issues/24958 and partly due to the low execution frequency of GC Server Mode in GC mode，But now I'm solving it by using GarbageCollectionAdaptationMode

[jinzaz]

But I found that YARP's CPU usage is very high, and I'm not sure if this is normal, or can you recommend optimization methods