When to use Azure Web Job and Azure Functions

Web Jobs are suitable for continuously running jobs. Azure function is not supported or designed for it.


Web job is a supporting mechanism to an existing application. Azure functions can be a supporting application or an application itself.


Web Jobs can have only 2 triggers (Manual or Timer). Azure Functions can have different triggers (Queue, Blob Storage, table storage etc)


Azure functions can be triggered from external events (Example - When message comes to Queue/Bus, New file is uploaded to blob storage etc). Web Jobs cannot do this.

Availability set and Availability Zone

One of the business continuity strategy is high availability. Availability set & Availability Zone helps to achieve this. This ensure availability of apps during catastrophic failures.

Availability set - VMs are placed within the same data center. Keep them in different racks. So that one goes down, other is available.

Availability Zone - VMs are placed in different data centers under same region

Cloud Migration Strategies

1. Rehost
2. Refactor
3. Re-architect

Rehost - This is the fastest way to move to cloud. Move all your workload to VM. Also known as "lift and shift". IaaS.


Refactor - Make few changes in the application and host it on Azure. This is through PaaS. (Example: Azure App Service or Azure SQL)


Re-architect - Breakdown large application into smaller micro-services. Or through SaaS offering

Azure Web Job

Web job is a process that runs in the background. It complements the main application. In other words, it is supporting mechanism to an existing application.

There are 2 types of Web Jobs:

1. Continuous Web Job
2. Triggered Web Job

Continuous Web Job runs until it stopped.

Triggered Web Job will only run when triggered.

Triggered Web Job can start in 2 ways:

1. Manual
2. Scheduled

Observations:

• Web job can be configured on any existing Azure App Service (Web App or Web Api)
• Web job supports .exe, .ps, .cmd etc.
• Dotnet framework console application can be configured as Web Job
• By default, dotnet core console project output is dll. Hence may not be able to configure directly
• Web job can be scheduled using CRON expressions

Azure Application Insights - Observations

• There is few minutes delay in seeing logs in Azure Application Insights
• Data retention can be up to 730 days(2 years). Upto 90 days is free, post that is chargeable.
• Instrumentation key uniquely identifies Application Insights in Azure portal
• A local web app (not published) with Instrumentation Key can send messages to Application Insights
• Use TelemetryClient to log custom events into Azure Application Insights
• Kusto Query Language (KQL) - helps to query Application Insights