.NET Web API集成OpenTelemetry后内存持续增长问题求助

我在.NET Web API中集成OpenTelemetry库后，出现内存占用持续增长直至触发Pod内存限制导致重启的问题：开发环境下API流量极低且稳定（约4请求/秒，90%为FrontDoor健康检查），但Pod内存6小时内从375MB增至506MB（涨幅35%），后续10小时内进一步升至710MB后Pod重启。

对比间隔6小时的两份GC Dump，发现第二份Dump中新增了106,078个Activity对象、1,060,780个DiagNode<KeyValuePair<String, Object>>对象等。在Visual Studio中对比GC Dump，得到包含15个最大包含大小差异对象的列表（截图：）

使用的OpenTelemetry相关库版本 #

<PackageReference Include="OpenTelemetry" Version="1.6.0" />
<PackageReference Include="OpenTelemetry.Exporter.Console" Version="1.6.0" />
<PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.6.0" />
<PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.6.0" />
<PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.5.1-beta.1" />
<PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.5.1-beta.1" />
<PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.5.1" />
<PackageReference Include="OpenTelemetry.Instrumentation.SqlClient" Version="1.5.1-beta.1" />

Startup.cs中OpenTelemetry配置方法 #

public static IServiceCollection SetupOpenTelemetry(IServiceCollection services, IConfiguration configuration, TracingOptions options)
{
    if (!options.OpenTelemetry.Enabled)
        return services;

    if (string.IsNullOrWhiteSpace(options.OpenTelemetry.EndpointUrl))
        throw new InvalidOperationException("OpenTelemetry EndpointUrl is not configured.");
    if (string.IsNullOrWhiteSpace(options.OpenTelemetry.ServiceName))
        throw new InvalidOperationException("OpenTelemetry ServiceName is not configured.");

    var environmentOptions = configuration.GetRequiredSection(EnvironmentOptions.SectionName).Get<EnvironmentOptions>()
        ?? throw new InvalidOperationException($"Cannot bind {EnvironmentOptions.SectionName} section.");

    if (string.IsNullOrWhiteSpace(environmentOptions.Name))
        throw new InvalidOperationException("Environment Name is not configured.");

    var serviceAttributes = new[]
    {
        new KeyValuePair<string, object>("service.version", Assembly.GetExecutingAssembly().GetName().Version.ToString()),
        new KeyValuePair<string, object>("service.environment", environmentOptions.Name)
    };

    var resourceBuilder = 
        ResourceBuilder.CreateDefault()
            .AddService(options.OpenTelemetry.ServiceName)
            .AddAttributes(serviceAttributes);

    services.AddOpenTelemetry()
        .WithMetrics(builder =>
        {
            builder
                .SetResourceBuilder(resourceBuilder) 
                .AddAspNetCoreInstrumentation()
                .AddHttpClientInstrumentation()
                .AddRuntimeInstrumentation()
                .AddOtlpExporter(exporter =>
                {
                    exporter.Endpoint = new Uri(options.OpenTelemetry.EndpointUrl);
                    exporter.Headers = $"lightstep-access-token={options.OpenTelemetry.AccessToken}";
                });
        })
        .WithTracing(builder =>
        {
            builder.AddSource("Npgsql")
            .SetResourceBuilder(resourceBuilder)
            .SetSampler(new AlwaysOnSampler())
            .AddAspNetCoreInstrumentation(o =>
            {
                o.RecordException = true;
                o.EnrichWithHttpRequest = (activity, request) =>
                {
                    activity.SetTag("size", request.HttpContext.Response.ContentLength ?? 0);
                };
                o.EnrichWithException = (activity, exception) =>
                {
                    activity.SetTag("stackTrace", exception.StackTrace);
                };
            })
            .AddHttpClientInstrumentation(o =>
            {
                o.RecordException = true;
                o.EnrichWithException = (activity, exception) =>
                {
                    activity.SetTag("stackTrace", exception.StackTrace);
                };
            })
            .AddSqlClientInstrumentation(o =>
            {
                o.RecordException = true;
                o.SetDbStatementForText = true;
                o.EnableConnectionLevelAttributes = true;
            })
            .AddOtlpExporter(o =>
            {
                o.Endpoint = new Uri(options.OpenTelemetry.EndpointUrl);
                o.Headers = $"lightstep-access-token={options.OpenTelemetry.AccessToken}";
            });

            if (options.OpenTelemetry.EnableConsoleExport)
            {
                builder.AddConsoleExporter();
            }
        });

    return services;
}

OtlpExporter的Endpoint为https://ingest.lightstep.com

请问是什么原因导致Activity等对象无法从内存中释放？是否有类似的经验可以分享？

内容的提问来源于stack exchange，提问作者Petofi