AZ-204 - Developer associate - Monitor, Troubleshoot and Monitor

Last updated Aug 3, 2022 Published Jun 20, 2022

Azure offer different services to troubleshoot and monitor applications, it might vary based on the type of application you are building. Nevertheless, application insights could be of help to mitigate issues. In this section we will go through those services to better understand their purpose and what they do as well as tips that could be helpful while studying.

Application insights

  • Concepts
    • Application performance
    • Monitor applications
    • Diagnose issues
  • Install a instrumentation package
  • Monitored aspects
    • Request rate
    • Exceptions
    • Page views
    • User sessions count
    • Performance of underlying machine
    • Custom metrics written in the code
  • Installation
    • Visual studio
      • creates a web mvc application
      • From Project click on “Add Application Insights Telemetry”
      • It can be install locally or use azure
  • Creating app insights
    • telemetry is stored in a log workspace
    • in dot net app, it stores the instrumentation key under Secrets.json file
    • Insights allows dependency tracking from sql server

CLI

this section was not asked in any of the mock exams

Azure CLI offers a application insights extension (for the time being it is not official, but as this is a developer associate exam I thought it is worth to mention it here).

az monitor app-insights query --app myapp -g mygroup --analytics-query 'traces | where message contains "bla"' --start-time 2022-07-10T09:10:00.000Z -o table

For further reference, follow this issue created in the official github repository.

Tracking users

By default insights adds a random id from the user that, to corelate that with a actual user from an app, a custom metrics is needed. In c# (dotnet core) it is done extending the class TelemetryInitializeBase

Tracking page views

Can be done via javascript embedded in the html page

Application map

Draws a diagram based on the requests tracked by insights

Insights funnel

User flows

Availability

  • URL ping
  • Multi step test

Web site scale

https://docs.microsoft.com/en-us/azure/app-service/web-sites-scale

Web logic apps

Web logic app is an azure service that allows developers to integrate different services in the cloud. Some of the examples shared in the official documentation are:

  • React to an event that happened in office 365
  • Move uploaded files from an SFTP or FTP server to Azure Storage.
  • Monitor tweets

Caching

Cache-Aside

Load data on demand into a cache from a data store. This can improve performance and also helps to maintain consistency between data held in the cache and data in the underlying data store.

CDN

The caching behaviors that are offered by azure are something to keep in mind while preparing for the exam.

  • Bypass cache
  • Override
  • Set if missing

CDN settings

  • Ignore query string
  • Bypass caching for query string
  • Cache every unique URL

Azure cache for redis

  • Managed redis

Caching rules

  • Bypass cache
  • Default
  • Override
  • Set if missing/cosmos

Front door

Azure front door is a CDN service that provides the deliver of large file sizes without cap on file size.

Front door supports different mime types as well as compression. The full list is available under Microsoft’s official front door documentation.

Purge caching

  • Single path value
  • Wildcard purge
  • Root domain purge