为什么 ILogger 不记录到 Azure 应用程序见解？

Question

我正在直接从这里测试控制台应用程序的代码： https: //learn.microsoft.com/en-us/azure/azure-monitor/app/ilogger#

我基本上复制了代码并将其指向一个新的 azure 应用程序见解实例。但是，应用程序见解中没有显示任何日志。我错过了什么吗？

 static void Main(string[] args)
        {
            // Create DI container.
            IServiceCollection services = new ServiceCollection();

            // Add the logging pipelines to use. We are using Application Insights only here.
            services.AddLogging(loggingBuilder =>
            {
                // Optional: Apply filters to configure LogLevel Trace or above is sent to ApplicationInsights for all
                // categories.
                loggingBuilder.AddFilter<ApplicationInsightsLoggerProvider>("", LogLevel.Trace);
                loggingBuilder.AddApplicationInsights(******);
            });

            // Build ServiceProvider.
            IServiceProvider serviceProvider = services.BuildServiceProvider();

            ILogger<Program> logger = serviceProvider.GetRequiredService<ILogger<Program>>();


            logger.LogCritical("critical message working");
            // Begin a new scope. This is optional. Epecially in case of AspNetCore request info is already
            // present in scope.
            using (logger.BeginScope(new Dictionary<string, object> { { "Method", nameof(Main) } }))
            {
                logger.LogWarning("Logger is working - warning"); // this will be captured by Application Insights.

            }
        }

Answer 1

代码是正确的，但您遇到了 ApplicationInsights 和控制台应用程序的已知问题 - 在 ApplicationInsights 可以将数据发送到后端之前应用程序已死亡。（数据不是立即发送，而是分批发送，间隔发送。）

添加约 30 秒的睡眠时间应该会对您的情况有所帮助。线程.睡眠(31000);

在常规控制台应用程序中，文档建议进行显式刷新。 https://learn.microsoft.com/en-us/azure/azure-monitor/app/console#full-example

但在 ILogger 情况下，您无法控制 TelemetryClient 实例。因此，最好的选择是控制通道，并在通道上调用flush，然后进行短暂的睡眠。修改后的代码如下。

class Program
    {
        static void Main(string[] args)
        {
            // Create DI container.
            IServiceCollection services = new ServiceCollection();

            var channel = new InMemoryChannel();

            services.Configure<TelemetryConfiguration>(
              (config) =>
                {
                    config.TelemetryChannel = channel;                    
                }
           );

            // Add the logging pipelines to use. We are using Application Insights only here.
            services.AddLogging(loggingBuilder =>
            {
                // Optional: Apply filters to configure LogLevel Trace or above is sent to ApplicationInsights for all
                // categories.
                loggingBuilder.AddFilter<ApplicationInsightsLoggerProvider>("", LogLevel.Trace);
                loggingBuilder.AddApplicationInsights("***");
            });

            // Build ServiceProvider.
            IServiceProvider serviceProvider = services.BuildServiceProvider();

            ILogger<Program> logger = serviceProvider.GetRequiredService<ILogger<Program>>();


            logger.LogCritical("critical message working");
            // Begin a new scope. This is optional. Epecially in case of AspNetCore request info is already
            // present in scope.
            using (logger.BeginScope(new Dictionary<string, object> { { "Method", nameof(Main) } }))
            {
                logger.LogWarning("Logger is working - warning"); // this will be captured by Application Insights.

            }

            channel.Flush();
            Thread.Sleep(1000);            
        }
    }