Logging

Serilog configuration reference for log levels, file rotation, and structured output.

Log Outputs ​

Console Logging ​

• Displays real-time logs with timestamp formatting
• Information level and above shown by default
• Color-coded by severity level
• Useful for development and debugging

File Logging ​

• Stored in the /log directory
• Daily rotation with pattern: portwayapi-YYYYMMDD.log
• 10MB file size limit with automatic rollover
• Retains 10 days of log files
• Buffered writing for performance

Log Levels ​

Configuration ​

Logging is configured in appsettings.json under the Serilog section. See Application Settings for the full configuration schema.

Log File Management ​

Rotation Policy ​

• Daily rotation at midnight
• Size-based rotation at 10MB
• Automatic file naming with date suffix

Retention Policy ​

• Keeps last 10 log files
• Older files automatically deleted
• Configurable retention period

File Naming Convention ​

log/
├── portwayapi-20240120.log
├── portwayapi-20240119.log
└── portwayapi-20240118.log

Performance Logging ​

Request Timing ​

[DBG] Incoming request: POST /api/500/Orders
[DBG] Outgoing response: 200 for /api/500/Orders - Took 125ms

Rate Limiting ​

[INF] Rate limiter initialized - IP: 100/60s, Token: 1000/60s
[INF] IP 192.168.1.100 has exceeded rate limit, blocking for 60s
[DBG] Rate limit for IP 192.168.1.100 has expired, allowing traffic

Structured Logging ​

Event Properties ​

The logging system captures structured data for better analysis:

• Request method and path
• User identity and token information
• Environment and endpoint names
• Duration and status codes
• Error details and stack traces

Context Enrichment ​

Logs are automatically enriched with:

• Machine name
• Application version
• Request correlation IDs
• User context
• Environment information

Troubleshooting ​

Common Issues ​

1. Missing Log Files

   • Check write permissions on log directory
   • Verify log path configuration
   • Ensure application has started successfully

2. Excessive Log Volume

   • Adjust minimum log levels
   • Enable filtering for noisy components
   • Configure appropriate retention policies

3. Performance Impact

   • Enable buffered writing
   • Increase flush intervals
   • Filter high-frequency events

Diagnostic Tools ​

PowerShell commands for log analysis:

# Find errors in today's log
Get-Content "log/portwayapi-$(Get-Date -Format 'yyyyMMdd').log" | Select-String "ERR"

# Count requests by endpoint
Get-Content "log/portwayapi-*.log" | Select-String "Processing.*endpoint:" | Group-Object

# Monitor log growth
Get-ChildItem "log" -Filter "*.log" | Sort-Object LastWriteTime -Descending | Select-Object Name, Length