Inhaltsverzeichnis

Runbook: Check Logs

Runbook: Check Logs

Duration: ~10 minutes
Role: Gateway Operator
Frequency: Daily / On issues

Analysis of Gateway logs for error diagnosis and monitoring.

Workflow

flowchart TD A[Open logs] --> B[Filter for ERROR] B --> C{Errors found?} C -->|Yes| D[Analyze error] C -->|No| E[Filter for WARN] D --> F[Take action] E --> G{Warnings?} G -->|Yes| H[Document] G -->|No| I[OK - Done] F --> I H --> I style I fill:#e8f5e9 style D fill:#ffebee style H fill:#fff3e0

1. Log Locations

Platform	Path
———-	——
Windows (Console)	Console output
Windows (Service)	`%GATEWAY_ROOT%\logs\` or Event Log
Linux (systemd)	`journalctl -u data-gateway`
Docker	`docker logs gateway`

2. Show Recent Logs

Windows (File):

# Last 50 lines
Get-Content -Path "%GATEWAY_ROOT%\logs\gateway.log" -Tail 50
 
# Live tail
Get-Content -Path "%GATEWAY_ROOT%\logs\gateway.log" -Wait -Tail 10

Linux (systemd):

# Last 100 lines
journalctl -u data-gateway -n 100 --no-pager
 
# Live tail
journalctl -u data-gateway -f

Docker:

# Last 100 lines
docker logs --tail 100 gateway
 
# Live tail
docker logs -f gateway

3. Filter for Errors

Windows:

# ERROR entries
Select-String -Path "%GATEWAY_ROOT%\logs\*.log" -Pattern "ERROR|Exception"
 
# Today
Get-Content "%GATEWAY_ROOT%\logs\gateway.log" | Where-Object { $_ -match "ERROR" -and $_ -match (Get-Date -Format "yyyy-MM-dd") }

Linux:

# ERROR entries
journalctl -u data-gateway --since today | grep -E "ERROR|Exception"
 
# Or in file
grep -E "ERROR|Exception" /var/log/gateway/gateway.log

4. Common Log Patterns

Successful request:

[INFO] GET /api/v1/dsn/demo/tables 200 45ms

Error:

[ERROR] GET /api/v1/dsn/invalid/tables 404 Database 'invalid' not found
[ERROR] POST /api/v1/dsn/demo/query 500 SqlException: Invalid syntax

Warning:

[WARN] Slow query detected: 2340ms for GET /api/v1/dsn/production/tables/BigTable

5. Adjust Log Level

In appsettings.json:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "WvdS.WebAPI.Data.Gateway": "Debug"
    }
  }
}

Level	Usage
——-	——-
`Trace`	Very detailed (development)
`Debug`	Debugging information
`Information`	Normal operations (default)
`Warning`	Potential problems
`Error`	Errors that were handled
`Critical`	Severe errors, crash

6. Checklist

#	Check	Done
—	——-	——
1	ERROR entries reviewed	[ ]
2	WARN entries reviewed	[ ]
3	Slow queries noted	[ ]
4	Errors documented/reported	[ ]
5	Log rotation active	[ ]

Troubleshooting

Log Message	Cause	Solution
————-	——-	———-
`Database not found`	DSN not configured	Check appsettings.json
`Connection refused`	DB not reachable	Check firewall/network
`SqlException: Login failed`	Wrong credentials	Check password
`OutOfMemoryException`	Query too large	Set `$top` limit
`Timeout expired`	DB too slow	Optimize index

Set Up Log Rotation

Serilog (appsettings.json):

{
  "Serilog": {
    "WriteTo": [
      {
        "Name": "File",
        "Args": {
          "path": "logs/gateway-.log",
          "rollingInterval": "Day",
          "retainedFileCountLimit": 30
        }
      }
    ]
  }
}

Related Runbooks

Health Check - Availability check
Start Server - On crash
Alerting - Automatic notification

« <- Health Check | -> Operator Overview »

Wolfgang van der Stille @ EMSR DATA d.o.o. - Data Gateway Professional

operator, runbook, logs, troubleshooting