Geocoding service metrics

[jmarin]

The geocoding service needs to capture metrics of its runtime performance. Metrics should be stored and able to be queried on demand

• Tools for metrics logging Tools for metrics logging #72
• Point geocode execution time Measure point geocoding performance #37
• 404 errors 404 errors #73
• System health System health #74
• Usage of system Usage of system #75
• Address error rate Address error rate #76
• Metrics UI display Metrics UI display #78