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PASSEDserver / iis_app_pool_crash
IIS Application Pool Crash Loop
The IIS application pool for a critical internal web application enters a crash loop after a .NET runtime update. The worker process (w3wp.exe) crashes within seconds of starting, and IIS rapid-fail protection disables the pool after 5 crashes in 5 minutes.
Pattern
PROCESS_CRASH_LOOP
Severity
CRITICAL
Confidence
90%
Remediation
Auto-Heal
Test Results
| Metric | Expected | Actual | Result |
|---|---|---|---|
| Pattern Recognition | PROCESS_CRASH_LOOP | PROCESS_CRASH_LOOP | |
| Severity Assessment | CRITICAL | CRITICAL | |
| Incident Correlation | Yes | 9 linked | |
| Cascade Escalation | N/A | No | |
| Remediation | — | Auto-Heal — Corax resolves autonomously |
Scenario Conditions
Windows Server 2022 running IIS 10. .NET 6 runtime updated to 6.0.28. Application pool 'InternalPortalAppPool' crashing on start. Rapid-fail protection threshold: 5 crashes in 5 minutes. 200 internal users affected.
Injected Error Messages (2)
IIS application pool InternalPortalAppPool in crash loop — w3wp.exe worker process crashing within 3 seconds of start, rapid-fail protection triggered after 5 crashes in 5 minutes, app pool disabled, event ID 5011: worker process crash loop detected, .NET runtime exception during CLR initialization
IIS health endpoint returning HTTP 503 Service Unavailable — application pool stopped due to crash loop, w3wp.exe generating crash dump on every start attempt, all requests to internal portal failing
Neural Engine Root Cause Analysis
The IIS application pool InternalPortalAppPool is experiencing a crash loop where the w3wp.exe worker process repeatedly crashes within 3 seconds of startup due to a .NET runtime exception during CLR initialization. This indicates a fundamental issue with the .NET application's ability to initialize, potentially caused by corrupted application files, missing dependencies, configuration errors, or resource constraints. The rapid-fail protection has automatically disabled the application pool after 5 crashes in 5 minutes to prevent further system instability.
Remediation Plan
1. Attempt to restart the IIS application pool to clear transient issues 2. If restart fails, check application event logs for specific .NET CLR errors 3. Verify application dependencies and configuration files 4. Check system resources (memory, disk space) 5. If issues persist, perform IIS reset 6. As last resort, redeploy application binaries if corruption is suspected
Tested: 2026-03-30Monitors: 2 | Incidents: 2Test ID: cmncjxwau05ojobqexpcca7zl