I'm having some trouble with logging in Azure. I'm using the AzureAppServices FileLoggingProvider.

It doesn't seem to be a simple configuration issue as I can actually confirm that for the first log message that get's written (the first time a new log file is created) the logging is working correctly and I can see it within the log stream in the azure portal. After that no log messages are written. I thought it might be a buffering issue but I waited for 20 minutes and still didn't see any new log messages coming in. If I delete the log file then new log messages are immediately written to a new file and I can see them in the log stream. I'm using mostly default options for my logging configuration

builder.Services.Configure<AzureFileLoggerOptions>(options =>
{
    options.FileName = "azure-diagnostics-";
    options.FileSizeLimit = 50 * 1024;
    options.RetainedFileCountLimit = 5;
});

I'm having some trouble with logging in Azure. I'm using the AzureAppServices FileLoggingProvider.

It doesn't seem to be a simple configuration issue as I can actually confirm that for the first log message that get's written (the first time a new log file is created) the logging is working correctly and I can see it within the log stream in the azure portal. After that no log messages are written. I thought it might be a buffering issue but I waited for 20 minutes and still didn't see any new log messages coming in. If I delete the log file then new log messages are immediately written to a new file and I can see them in the log stream. I'm using mostly default options for my logging configuration

builder.Services.Configure<AzureFileLoggerOptions>(options =>
{
    options.FileName = "azure-diagnostics-";
    options.FileSizeLimit = 50 * 1024;
    options.RetainedFileCountLimit = 5;
});

• c#
• azure
• logging
• azure-appservice

• The issue above occurs when file locking or log buffering happens within the logging provider. have tries alternate with enabling application insights. – Suresh Chikkam Commented Feb 18 at 6:23
• Try reducing FileSizeLimit. – Suresh Chikkam Commented Feb 18 at 7:14

1 Answer 1

Many of the users have reported that the log file becomes locked, preventing further writes. Deleting the existing log file forces the system to create a new one, this will temporarily resolve the issue.

And also, observed that logs are buffered and not immediately flushed to the file system, leading to delays in log visibility. Adjusting the logging configuration to reduce buffering intervals can clear this problem.

• Try using Application Insights, it is a telemetry and logging platform offers real-time monitoring of log events. Add the Microsoft.Extensions.Logging.ApplicationInsights package and configure Application Insights in the app.

builder.Services.AddApplicationInsightsTelemetry();
builder.Logging.AddApplicationInsights();

Monitor logs in the Azure Portal under the Application Insights resource.