API Application Insights good practice to use

Question

I read this documentation: https://docs.microsoft.com/en-us/azure/application-insights/app-insights-api-custom-events-metrics

There are many different API method to track exceptions, track trace etc..

I have a ASP.NET MVC 5 application. For example, I have the following controller method (called by ajax):

    [AjaxErrorHandling]
    [HttpPost]
    public async Task SyncDriverToVistracks(int DriverID)
    {
            if ([condition])
            {
                // some actions here

                try
                {
                    driver.VistrackId = await _vistracksService.AddNewDriverToVistrackAsync(domain);
                    await db.SaveChangesAsync();
                }
                catch (VistracksApiException api_ex)
                {
                    // external service throws exception type VistracksApiException 
                    throw new AjaxException("vistracksApiClient", api_ex.Response.Message);
                }
                catch (VistracksApiCommonException common_ex)
                {
                    // external service throws exception type VistracksApiCommonException 
                    throw new AjaxException("vistracksApiServer", "3MD HOS server is not available");
                }
                catch (Exception ex)
                {
                    // something wrong at all
                    throw new AjaxException("General", ex.Message);
                }
            }
            else
            {
                // condition is not valid
                throw new AjaxException("General", "AccountId is not found");
            }
    }

this method throws AjaxException if something wrong (which catch by AjaxErrorHandling and then return something json response to client).

Now I want to add telemetry for logging, analyzing exceptions and observe on client events.

So, I added the following:

    [AjaxErrorHandling]
    [HttpPost]
    public async Task SyncDriverToVistracks(int DriverID)
    {
            telemetryClient.TrackEvent("Sync driver", new Dictionary<string, string> { { "ChangedBy", User.Identity.Name }, { "DriverID", DriverID.ToString() } }, null);
            if ([condition])
            {
                // some actions here

                try
                {
                    driver.VistrackId = await _vistracksService.AddNewDriverToVistrackAsync(domain);
                    await db.SaveChangesAsync();
                }
                catch (VistracksApiException api_ex)
                {
                    // external service throws exception type VistracksApiException 
                    telemetryClient.TrackTrace("VistracksApiException", new Dictionary<string, string> {
                        { "ChangedBy", User.Identity.Name },
                        { "DriverID", DriverID.ToString() },
                        { "ResponseCode", api_ex.Response.Code.ToString() },
                        { "ResponseMessage", api_ex.Response.Message },
                        { "ResponseDescription", api_ex.Response.Description }
                    });
                    telemetryClient.TrackException(api_ex);

                    throw new AjaxException("vistracksApiClient", api_ex.Response.Message);
                }
                catch (VistracksApiCommonException common_ex)
                {
                    // external service throws exception type VistracksApiCommonException 
                    telemetryClient.TrackTrace("VistracksApiCommonException", new Dictionary<string, string> {
                        { "ChangedBy", User.Identity.Name },
                        { "DriverID", DriverID.ToString() },
                        { "Message", common_ex.Message },
                    });
                    telemetryClient.TrackException(common_ex);
                    throw new AjaxException("vistracksApiServer", "3MD HOS server is not available");
                }
                catch (Exception ex)
                {
                    // something wrong at all
                    telemetryClient.TrackTrace("Exception", new Dictionary<string, string> {
                        { "ChangedBy", User.Identity.Name },
                        { "DriverID", DriverID.ToString() },
                        { "Message", ex.Message },
                    });
                    telemetryClient.TrackException(ex);
                    throw new AjaxException("General", ex.Message);
                }
            }
            else
            {
                telemetryClient.TrackTrace("ConditionWrong", new Dictionary<string, string> {
                    { "ChangedBy", User.Identity.Name },
                    { "DriverID", DriverID.ToString() },
                    { "Message", "AccountId is not found" },
                });
                // condition is not valid
                throw new AjaxException("General", "AccountId is not found");
            }
    }

by the following line:

        telemetryClient.TrackEvent("Sync driver", new Dictionary<string, string> { { "ChangedBy", User.Identity.Name }, { "DriverID", DriverID.ToString() } }, null);

I just "log" client event, that the method was called. Just for statistics.

In each "catch" block I try to write trace with different parameters and write exception:

                    telemetryClient.TrackTrace("trace name", new Dictionary<string, string> {
                        { "ChangedBy", User.Identity.Name },
                        ....
                    });
                    telemetryClient.TrackException(ex);

Is it necessary? Or just need to track only exception? Then I lose different info, like who try to add these changes etc... When each of these methods should be used?

Answer 1

This is the best practice for 2.5.1 AI SDK. Will highlight parts which might not be required in upcoming AI SDK releases.

The right way to do end-to-end tracing is to rely on new Activity class in .NET framework. Until AI supports Activity.Tags (https://github.com/Microsoft/ApplicationInsights-dotnet/issues/562) you need to propagate them manually using TelemetryInitializer:

public class ActvityTagsTelemetryInitializer : ITelemetryInitializer
{
    public void Initialize(ITelemetry telemetry)
    {
        Activity current = Activity.Current;

        if (current == null)
        {
            current = (Activity)HttpContext.Current?.Items["__AspnetActivity__"];
        }

        while (current != null)
        {
            foreach (var tag in current.Tags)
            {
                if (!telemetry.Context.Properties.ContainsKey(tag.Key))
                {
                    telemetry.Context.Properties.Add(tag.Key, tag.Value);
                }
            }

            current = current.Parent;
        }
    }
}

Then register it in ApplicationInsights.config:

  <TelemetryInitializers>
    ...
    <Add Type="<namespace>.ActvityTagsTelemetryInitializer, <assemblyname>"/>
  </TelemetryInitializers>

Then you can populate proper tags:

[AjaxErrorHandling]
[HttpPost]
public async Task SyncDriverToVistracks(int DriverID)
{
    Activity.Current.AddTag("DriverID", DriverID.ToString());
    Activity.Current.AddTag("UserID", User.Identity.Name);

    try
    {
        if ([condition])
        {
            // some actions here

            try
            {
                // If below call is HTTP then no need to use StartOperation
                using (telemetryClient.StartOperation<DependencyTelemetry>("AddNewDriverToVistrackAsync"))
                {
                    driver.VistrackId = await _vistracksService.AddNewDriverToVistrackAsync(domain);
                }

                // If below call is HTTP then no need to use StartOperation
                using (telemetryClient.StartOperation<DependencyTelemetry>("SaveChanges"))
                {
                    await db.SaveChangesAsync();
                }
            }
            catch (VistracksApiException api_ex)
            {
                // external service throws exception type VistracksApiException 
                throw new AjaxException("vistracksApiClient", api_ex.Response.Message);
            }
            catch (VistracksApiCommonException common_ex)
            {
                // external service throws exception type VistracksApiCommonException 
                throw new AjaxException("vistracksApiServer", "3MD HOS server is not available");
            }
            catch (Exception ex)
            {
                // something wrong at all
                throw new AjaxException("General", ex.Message);
            }
        }
        else
        {
            // condition is not valid
            throw new AjaxException("General", "AccountId is not found");
        }
    }
    catch (Exception ex)
    {
        // Upcoming 2.6 AI SDK will track exceptions for MVC apps automatically.
        telemetryClient.TrackException(ex);
        throw;
    }
}

You should have the following telemetry:

1. Incoming request
2. Outgoing requests (dependencies)
3. Exceptions for failed requests

All telemetry will be stamped with ChangedBy and DriverID