Prometheus Metrics

[sv2]

Expose metrics for Prometheus via /swagger-stats/metrics API

[sv2]

Prometheus metrics are exposed now via /swagger-stats/metrics API.

Example:

$ curl http://<your app host:port>/swagger-stats/metrics
# HELP api_all_request_total The total number of all API requests received
# TYPE api_all_request_total counter
api_all_request_total 88715
# HELP api_all_success_total The total number of all API requests with success response
# TYPE api_all_success_total counter
api_all_success_total 49051
. . . . . 

The following metrics are provided:

Name	Type	Help
api_all_request_total	counter	The total number of all API requests received
api_all_success_total	counter	The total number of all API requests with success response
api_all_errors_total	counter	The total number of all API requests with error response
api_all_client_error_total	counter	The total number of all API requests with client error response
api_all_server_error_total	counter	The total number of all API requests with server error response
api_all_request_in_processing_total	gauge	The total number of all API requests currently in processing (no response yet)
nodejs_process_memory_rss_bytes	gauge	Node.js process resident memory (RSS) bytes
nodejs_process_memory_heap_total_bytes	gauge	Node.js process memory heapTotal bytes
nodejs_process_memory_heap_used_bytes	gauge	Node.js process memory heapUsed bytes
nodejs_process_memory_external_bytes	gauge	Node.js process memory external bytes
nodejs_process_cpu_usage_percentage	gauge	Node.js process CPU usage percentage
api_request_total	counter	The total number of all API requests
api_request_duration_milliseconds	histogram	API requests duration
api_request_size_bytes	histogram	API requests size
api_response_size_bytes	histogram	API response size

Added Grafana dashboard, see dashboards/prometheus