When preparing a web application for deployment on IIS 7, comprehensive load testing is non-negotiable. Here are the most effective tools I've used in production environments:

// Example JMeter Test Plan snippet for IIS 7 testing
<TestPlan guiclass="TestPlanGui" testclass="TestPlan" testname="IIS7 Load Test">
  <stringProp name="TestPlan.comments">Simulating 1000 concurrent users</stringProp>
  <boolProp name="TestPlan.functional_mode">false</boolProp>
  <boolProp name="TestPlan.serialize_threadgroups">false</boolProp>
</TestPlan>

JMeter remains my top recommendation for IIS 7 testing due to:

• Protocol support (HTTP/HTTPS, SOAP, REST)
• Distributed testing capabilities
• Extensive reporting features

For teams with budget, these tools offer advanced IIS 7-specific features:

// LoadRunner configuration example for IIS
Action()
{
    web_url("homepage", 
        "URL=http://yoursite/iisapp/", 
        "Resource=0", 
        "RecContentType=text/html",
        LAST);
    return 0;
}

Services like Loader.io and BlazeMeter provide scalable options for:

• Geographically distributed testing
• Instant infrastructure provisioning
• Real-time analytics dashboards

Don't forget to monitor these key metrics during tests:

// PowerShell snippet to check IIS 7 performance counters
Get-Counter -Counter "\Web Service(_Total)\Current Connections" -SampleInterval 2 -MaxSamples 10
Get-Counter -Counter "\Process(w3wp)\% Processor Time" -SampleInterval 2 -MaxSamples 10

For automated pre-deployment validation:

# Azure DevOps YAML example for load testing
- task: JMeterLoadTest@1
  inputs:
    jmeterDirectory: '$(System.DefaultWorkingDirectory)/jmeter'
    testFile: 'IIS7_Test.jmx'
    resultFile: 'TestResults.jtl'
    cloudLoad: true
    machineCount: 5

When deploying web applications on IIS 7, load testing is crucial for identifying performance bottlenecks, capacity limits, and stability issues under concurrent user traffic. The right tools can simulate real-world usage patterns and help optimize your server configuration before production release.

An effective IIS 7 load testing solution should provide:

• Realistic HTTP request simulation
• Distributed load generation capabilities
• Detailed performance metrics (response times, throughput, error rates)
• Support for ASP.NET-specific monitoring
• Customizable test scenarios

1. JMeter with IIS 7 Plugins
Apache JMeter remains a popular open-source choice with excellent IIS integration:

<ThreadGroup guiclass="ThreadGroupGui" testclass="ThreadGroup" testname="IIS 7 Load Test" enabled="true">
  <elementProp name="ThreadGroup.main_controller" elementType="LoopController" guiclass="LoopControlPanel" testclass="LoopController" testname="Loop Controller" enabled="true">
    <boolProp name="LoopController.continue_forever">false</boolProp>
    <stringProp name="LoopController.loops">100</stringProp>
  </elementProp>
  <stringProp name="ThreadGroup.num_threads">50</stringProp>
  <stringProp name="ThreadGroup.ramp_time">60</stringProp>
</ThreadGroup>

2. WebLOAD Professional
This commercial tool offers specialized IIS 7 monitoring with JavaScript-based test scripting:

webLOAD.openTransaction("IIS7_Homepage");
webLOAD.httpGet("http://yourserver/default.aspx");
webLOAD.closeTransaction();

For larger scale testing, consider cloud solutions:

• LoadStorm (now part of SmartBear)
• BlazeMeter
• LoadImpact (k6)

When preparing your IIS 7 server for load testing:

appcmd.exe set config -section:system.applicationHost/applicationPools /[name='YourAppPool'].queueLength:50000 /commit:apphost

Key metrics to monitor during IIS 7 load tests:

Create custom PowerShell scripts to monitor IIS 7 during tests:

Get-Counter -Counter "\Process(w3wp)\% Processor Time" -SampleInterval 2 -MaxSamples 30
Get-Counter -Counter "\Web Service(_Total)\Current Connections"