Azure application insights for beginner Edit

The impact on your app's performance is small. Tracking calls are non-blocking, and are batched and sent in a separate thread.

Application Insights monitors

• Request rates, response times, and failure rates - Find out which pages are most popular, at what times of day, and where your users are. See which pages perform best. If your response times and failure rates go high when there are more requests, then perhaps you have a resourcing problem.
• Dependency rates, response times, and failure rates - Find out whether external services are slowing you down.
• Exceptions - Analyze the aggregated statistics, or pick specific instances and drill into the stack trace and related requests. Both server and browser exceptions are reported.
• Page views and load performance - reported by your users' browsers.
• AJAX calls from web pages - rates, response times, and failure rates.
• User and session counts.
• Performance counters from your Windows or Linux server machines, such as CPU, memory, and network usage.
• Host diagnostics from Docker or Azure.
• Diagnostic trace logs from your app - so that you can correlate trace events with requests.
• Custom events and metrics that you write yourself in the client or server code, to track business events such as items sold or games won.

good & Bad Traces, and Severity level in Trace logs

Traces are logged by the application & they help to zero in on the problems when something goes wrong with the application. The traces log information which is generally unstructured, but one thing that can be definitively learned from them is their severity level. There are 5 severity levels in application insights they are 0 - Verbose / Debug, 1 - Information, 2 - Warning, 3 - Error & 4 - Critical. An application can send good traces and bad traces, Debug & Information is good traces, Warning, Error & Critical are bad traces.

If you find that Not all log levels are being logged in Application Insights, that's because by default application insight is configured to only receive Warning, Error, Critical, You can make changes in the client application to send all trace levels to the application insights service.

for an asp .net core application you can set the Severity level in your applicatoin.json file.

  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },

for a python application you can use the setLevel function in the logging module

logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)

.Net Core Sample Code

Getting the application insights to work from your asp .net core application is very easy. Just follow the below instructions.

Step1: go to nuget package manager and install Microsoft.ApplicationInsights.AspNetCore

Step2: Modify the application.json file and add
  "ApplicationInsights": {
    "InstrumentationKey": "YOURKEY-a2ba-ec098fbc3c77"
  }

Step3:

Step4: Inject the ILogger through the constructor

private readonly ILogger _logger;
        
public YourControllerNameController(ILogger logger)
{
            // Hello world
            _logger = logger;
}

Step5: do the logging

_logger.LogDebug("debug");
_logger.LogInformation("info");
_logger.LogWarning("warning");
_logger.LogError("error");
_logger.LogCritical("critical");