Application Insight Introduction
=====================================

.. post:: Apr 20, 2019
   :tags: cloud, telemetry
   :category: ComputerScience

This blog introduces what Application Insight can do.

Application Insight Basics
================================

Application Insights is aimed at the development team, to help you understand how your app is performing and how it's being used.

.. image:: images/application_insight_overview.png

It includes functions: 

* Detect, triage, and diagnose issues in web apps and services (Detect: Know about any issues before your users, Triage: how many users are affected? How often does this happen? Diagnose: Where is the problem? When does it happen?)
* Detect issues through email and webhook alerts 
* Diagnose exceptions and web app performance issues 
* Perform root cause analysis with ad-hoc queries and full-text search 
* Live application monitoring 
* HTTP request rates, response times, success rates. 
* Dependency (HTTP & SQL) call rates, response times, success rates. 
* Exception traces from both server and client. 
* Page view counts, user and session counts, browser load times, exceptions. 
* AJAX call rates, response times and success rates. 
* Server performance counters. (your Windows or Linux server machines, such as CPU, memory, and network usage)
* Segmentation by client location, browser version, OS version, server instance, custom dimensions, and more. 
* Availability tests. 
* 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.
* Integrate with DevOps processes using Visual Studio Team Services
* Monitor web apps hosted on Azure, other cloud services, or on-premises servers
* Get started with Visual Studio or monitor existing apps without re-deploying

.. image:: images/application_insight_in_devops.png

Diagnostic and analytic tools:

* Smart and manual alerts on failure rates and other metrics, and on availability.
* Charts over time of aggregated metrics.
* Diagnostic search on instances of requests, exceptions, custom events, log traces, page views, dependency and AJAX calls.
* Analytics - a powerful query language over your telemetry
* Dashboards - compose the charts you need to monitor all your app components.
* The Dependency Duration chart shows the time taken by calls from your app to external components such as databases, REST APIs, or Azure blob storage.
* Application map
* Profiler
* Live Metrics Stream
* Visual Studio
* Snapshot debugger
* Power BI
* REST API
* Continuous Export

Other Good Articles
======================

Azure cloud service support: 
https://docs.microsoft.com/en-us/azure/azure-monitor/app/cloudservices

Feed PowerBI with application insight:
https://docs.microsoft.com/en-us/azure/azure-monitor/app/export-power-bi

Billing service
https://github.com/Microsoft/peek

Platform support:
https://docs.microsoft.com/en-us/azure/azure-monitor/app/platforms

Work item for app insight:
https://azure.microsoft.com/en-us/blog/application-insights-work-item-integration-with-visual-studio-team-services/

Application insight can also support Application Performance Management (APM) and AB testing.

*Written by Binwei@Singapore*