PowderCoatingLogix/src/PowderCoating.Web/LOGGING-GUIDE.md

Logging Guide for PowderCoating Application

Log File Locations

When you deploy the application to your testing server, logs will be written to:

On Windows Server

C:\inetpub\wwwroot\YourAppFolder\logs\

or wherever your application is deployed to.

Log Files Created

1. powdercoating-YYYYMMDD.txt - All application logs (Info, Warning, Error)

   • Contains general application activity
   • Includes request logs with user information
   • New file created daily
   • Keeps last 30 days

2. errors-YYYYMMDD.txt - Error logs only

   • Contains ONLY errors and critical issues
   • Check this file first when troubleshooting
   • New file created daily
   • Keeps last 90 days

What Gets Logged

Automatic Error Logging

• Unhandled Exceptions: All unhandled errors are automatically logged with:

  • Exception details and stack trace
  • URL path where error occurred
  • Username (or "Anonymous")
  • Request trace ID
  • Timestamp

• HTTP Requests: All requests are logged with:

  • HTTP method and path
  • Response status code
  • Duration
  • User information
  • IP address
  • User agent

Log Entry Format

2026-02-11 10:30:45.123 -05:00 [ERR] [PowderCoating.Web.Controllers.JobsController] Error creating job
System.InvalidOperationException: Job validation failed
   at PowderCoating.Web.Controllers.JobsController.Create(...)

Finding Logs on Your Testing Server

Step 1: Locate the Application Directory

1. Connect to your testing server via RDP
2. Navigate to where the application is deployed
3. Look for a logs folder in the application root

Step 2: Check for Permissions

The application needs write permissions to the logs folder. If no logs are created:

1. Right-click the logs folder → Properties → Security
2. Ensure the IIS application pool identity has "Modify" permissions
3. Typically this is IIS AppPool\YourAppPoolName

Step 3: View Current Errors

Open the most recent errors-YYYYMMDD.txt file to see all errors from today.

Troubleshooting: Logs Not Appearing

If logs folder doesn't exist:

1. The application may not have started successfully
2. Check Windows Event Viewer → Application logs for startup errors
3. Check IIS logs in C:\inetpub\logs\LogFiles\

If logs folder exists but empty:

1. Check folder permissions (application pool needs Write access)
2. Check if application is actually running
3. Restart the application pool in IIS Manager

If only seeing old logs:

1. Application may have crashed - check Windows Event Viewer
2. Application pool may have stopped - check IIS Manager
3. Restart the application pool to generate fresh startup logs

Log Levels by Environment

Development

• Logs everything at Information level and above
• Full console output with colors
• Detailed EF Core query logs

Production/Testing (Your Server)

• Logs Information level and above
• Warnings for Microsoft/System components
• Separate error log for quick troubleshooting
• Request logging enabled for audit trail

Reading the Logs

Finding Specific Errors

Use PowerShell to search logs:

# Find all errors today
Get-Content "logs\errors-$(Get-Date -Format yyyyMMdd).txt"

# Search for specific error
Select-String -Path "logs\*.txt" -Pattern "InvalidOperationException"

# Get last 50 error lines
Get-Content "logs\errors-*.txt" | Select-Object -Last 50

Common Log Patterns

Database Connection Error:

[ERR] An error occurred using the connection to database 'PowderCoatingDb'

Authentication Error:

[ERR] [Microsoft.AspNetCore.Authentication] Authentication failed

Unhandled Exception:

[ERR] [PowderCoating.Web.Controllers.*] Unhandled exception occurred

Additional Monitoring

Windows Event Viewer

For startup/crash errors that may not appear in application logs:

1. Open Event Viewer
2. Windows Logs → Application
3. Filter by Source: "ASP.NET Core"

IIS Logs

For HTTP-level issues:

• Location: C:\inetpub\logs\LogFiles\W3SVC*\
• Shows HTTP status codes, response times
• Useful for 500 errors, timeouts

Log Retention

• General Logs: Last 30 days automatically retained
• Error Logs: Last 90 days automatically retained
• Older logs are automatically deleted to save disk space
• Archive important logs if you need long-term retention

Performance Impact

The current logging configuration:

• Minimal impact on application performance
• Logs are written asynchronously
• File writes are flushed every 1 second
• shared: true allows multiple processes to write to same log file

Next Steps: Production Logging Improvements

For production deployment, consider:

1. Azure Application Insights - Cloud-based monitoring and alerting
2. Seq - Structured log server with web UI
3. ELK Stack - Elasticsearch, Logstash, Kibana
4. Centralized logging - Aggregate logs from multiple servers

Contact your DevOps team to set up one of these for production.