部署的.NET Core 6 Blazor Server应用清缓存后停止处理HTTP请求

问题现象 #

• 奥地利的iOS用户清理浏览器缓存并重连网站后，应用虽能正常打开，但不再处理任何HTTP请求（如URL加载的logo及其他资源请求）
• 该异常会影响所有其他客户端，并非仅出现问题的用户
• 部署环境：西欧区域的Azure App Service，Linux和Windows计划均存在此问题
• 基于SignalR构建，但日志（已开启DEBUG级别）未记录WebSocket断开错误，也无可用的错误追踪信息
• 尝试调整多种Hub连接配置（当前配置如下），问题仍未解决；本地环境无法复现该异常，页面加载正常无崩溃迹象

服务端配置 #

services.AddServerSideBlazor()
        .AddHubOptions(options =>
        {
            options.HandshakeTimeout = TimeSpan.FromSeconds(15);
            options.KeepAliveInterval = TimeSpan.FromSeconds(15);
            options.ClientTimeoutInterval = TimeSpan.FromSeconds(40);
            options.EnableDetailedErrors= true;

        })
        .AddCircuitOptions(options =>
        {
            options.DetailedErrors = true;
        });

客户端配置 #

public static HubConnection TryInitialize(this HubConnection hubConnection, NavigationManager navigationManager)
{
    if (hubConnection == null)
    {
        hubConnection = new HubConnectionBuilder()
                          .WithUrl(navigationManager.ToAbsoluteUri(ApplicationConstants.SignalR.HubUrl))
                          .Build();

        hubConnection.HandshakeTimeout = TimeSpan.FromSeconds(15);
        hubConnection.KeepAliveInterval = TimeSpan.FromSeconds(15);
        hubConnection.ServerTimeout = TimeSpan.FromSeconds(40);
    }

    return hubConnection;
}

日志配置 #

"Logging": {
"LogLevel": {
  "Default": "Debug",
  "Microsoft": "Debug",
  "Hangfire": "Debug",
  "Microsoft.Hosting.Lifetime": "Debug",
  "Microsoft.AspNetCore.HttpLogging.HttpLoggingMiddleware": "Debug",
  "Microsoft.AspNetCore.SignalR": "Debug"
}

_Layout页面配置 #

<body>
<div id="app">
@RenderBody()

<div id="blazor-error-ui">
    <environment include="Staging,Production">
        An error has occurred. This application may no longer respond until reloaded.
    </environment>
    <environment include="Development">
        An unhandled exception has occurred. See browser dev tools for details.
    </environment>
    <a href="" class="reload">Reload</a>
    <a class="dismiss">🗙</a>
</div>
<script src="_framework/blazor.server.js" autostart="false"></script>
<script>
    Blazor.start();
</script>
<script src="_content/MudBlazor/MudBlazor.min.js?v=5.0.5"></script>
<script src="js/scroll.js"></script>
<script src="js/sounds.js"></script>
<script src="js/file.js"></script>
<script src="js/script.js"></script>

求助 #

寻求有Azure App Service部署Blazor Server经验的人士提供排查方向。

内容的提问来源于stack exchange，提问作者ELA