CloudCostChefs: Oversized App Service Plan Detector (with Max Usage)

Overview

Meet your FinOps sous-chef: the Oversized App Service Plan Detector. This PowerShell recipe sniff tests CPU and memory usage over time to spot App Service Plans that are overcooked—letting you downsize with confidence and trim Azure costs without sacrificing performance.

More than just the bland “here’s your average” scoop, this script serves up both Avg and Max usage—think of it as tasting the simmer and the sizzle. With that dual-metric flavor, you get the full recipe for right-sizing your App Service Plans without underseasoning for peak loads.

Key Features

How It Works

The Oversized App Service Plan Detector is like a taste-test for your App Service Plans’ resource use over time—here’s the recipe it follows:

1. Discovery: Identifies all App Service Plans in the specified Azure subscription
2. Data Collection: Queries the Azure Monitor API to retrieve hourly CPU and memory metrics for each plan over the specified time period
3. Analysis: Calculates both average and maximum utilization for each plan
4. Identification: Flags plans as "underutilized" when both average CPU and memory usage fall below your specified thresholds
5. Reporting: Generates both console output and an HTML report with the findings

Prerequisites

Before you fire up the Oversized App Service Plan Detector, make sure your kitchen is stocked with these essentials:

• PowerShell 5.1 or higher - The script is compatible with both Windows PowerShell and PowerShell Core
• Az PowerShell Modules - Specifically, you'll need:
  • Az.Accounts - For Azure authentication
  • Az.Monitor - For accessing metrics data
• Azure Subscription - Active subscription with App Service Plans to analyze
• Appropriate Permissions - Reader access to the subscription and access to Azure Monitor metrics

Installation

Whipping up the Oversized App Service Plan Detector is a breeze:

1. Download the script - Save the Find-OversizedAppServicePlans.ps1 file to your preferred location
2. Verify execution policy - Ensure your PowerShell execution policy allows running the script
3. Install required modules - Make sure the Az.Accounts and Az.Monitor modules are installed

Usage

Basic Usage

To get cooking, just run the script as-is (no extra spices). It will:

• Use your current Azure context (subscription)
• Analyze usage over the last 7 days
• Flag plans with average CPU < 10% AND average memory < 10% as underutilized
• Save the report as "AppServicePlan-UsageReport.html" in the current directory
• Open the report in your default browser

Advanced Usage

This script comes with a spice rack of parameters so you can fine-tune the flavor:

Understanding the Report

The Oversized App Service Plan Detector serves up two courses: a console table and a CloudCostChefs-styled HTML report.

Console Output

The console output is your quick taste-test, showing:

• Analysis Parameters - Subscription, time window, and thresholds used
• Tabular Results - A formatted table showing all App Service Plans with their metrics
• Summary Statistics - Total plans scanned and number of underutilized plans
• Underutilized Plans - A focused list of just the plans flagged as underutilized

HTML Report

The HTML report is your chef’s table—richly detailed, visually appealing, and perfect for sharing with the whole kitchen brigade:

Customization Options

The Oversized App Service Plan Detector is great out of the box, but feel free to tweak the spices (parameters) to match your unique FinOps recipe.

# Find the HTML template section (starts with $html = @")
                   # Modify the CSS styles or HTML structure as needed
                   # For example, to change the background color:

                   body {
                       font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
                       margin: 0; padding: 40px; background-color: #f0f0f0; /* Changed color */
                   }

Automation

For regular monitoring of App Service Plan utilization, you can automate the Oversized App Service Plan Detector using various methods:

# Add this at the end of the script
                   $emailParams = @{
                       From       = "reports@yourcompany.com"
                       To         = "team@yourcompany.com"
                       Subject    = "App Service Plan Usage Report - $(Get-Date -Format 'yyyy-MM-dd')"
                       Body       = "Please find attached the latest App Service Plan usage report."
                       SmtpServer = "smtp.yourcompany.com"
                       Attachment = $OutputPath
                   }
                   Send-MailMessage @emailParams

Troubleshooting

Hit a snag in the kitchen with the Detector? Here are common recipe missteps and how to fix them:

Next Steps

Now that you’ve spotted the undercooked App Service Plans, here’s how to trim the fat and spice up your Azure cost savings: