KONG monitoring

KONG performance from kong prometheus plugin

The kong-prometheus is a lua library that can be used with Kong to collect metrics. It exposes metrics related to Kong and proxied upstream services in Prometheus exposition format, which can be scraped by a Prometheus Server. SkyWalking leverages OpenTelemetry Collector to transfer the metrics toOpenTelemetry receiver and into the Meter System.

Data flow

1. KONG Prometheus plugin collects metrics data from KONG.
2. OpenTelemetry Collector fetches metrics from KONG Prometheus plugin via Prometheus Receiver and pushes metrics to SkyWalking OAP Server via OpenTelemetry gRPC exporter.
3. The SkyWalking OAP Server parses the expression with MAL to filter/calculate/aggregate and store the results.

Set up

1. Enable KONG KONG Prometheus plugin. Note that if need to monitor per_consumer, status_code_metrics, ai_metrics, latency_metrics, bandwidth_metrics or upstream_health_metrics, need to enable them manually as needed, which can be enabled in the konga dashboard or through the Admin API, such as the following command

   curl -i -X POST http://{KONG-HOST}:{KONG_ADMIN_PORT}/plugins \
    --data name=prometheus \
    --data config.per_consumer=true \
    --data config.status_code_metrics=true \
    --data config.ai_metrics=true \
    --data config.latency_metrics=true \
    --data config.bandwidth_metrics=true \
    --data config.upstream_health_metrics=true
   

2. Set up OpenTelemetry Collector. For details on Prometheus Receiver in OpenTelemetry Collector, refer to here.
3. Config SkyWalking OpenTelemetry receiver.

KONG Monitoring

KONG prometheus plugin provide multiple dimensions metrics for KONG server, upstream, route etc. Accordingly, SkyWalking observes the status, requests, and latency of the KONG server, which is cataloged as a LAYER: KONG Service in the OAP. Each Kong server is cataloged as a LAYER: KONG instance, meanwhile, the route rules would be recognized as a LAYER: KONG endpoint.

Kong Request Supported Metrics

Monitoring Panel	Unit	Metric Name	Description	Data Source
Bandwidth	bytes	meter_kong_service_http_bandwidth meter_kong_instance_http_bandwidth meter_kong_endpoint_http_bandwidth	Total bandwidth (ingress/egress) throughput	Kong
HTTP Status	count	meter_kong_service_http_status meter_kong_instance_http_status meter_kong_endpoint_http_status	HTTP status codes per consumer/service/route in Kong	Kong
HTTP Request	count	meter_kong_service_http_requests meter_kong_instance_http_requests	Total number of requests	Kong

Kong Database Supported Metrics

Monitoring Panel	Unit	Metric Name	Description	Data Source
DB	count	meter_kong_service_datastore_reachable meter_kong_instance_datastore_reachable	Datastore reachable from Kong	Kong
DB	bytes	meter_kong_instance_shared_dict_bytes	Allocated slabs in bytes in a shared_dict	Kong
DB	bytes	meter_kong_instance_shared_dict_total_bytes	Total capacity in bytes of a shared_dict	Kong
DB	bytes	meter_kong_instance_memory_workers_lua_vms_bytes	Allocated bytes in worker Lua VM	Kong

Kong Latencies Supported Metrics

Monitoring Panel	Unit	Metric Name	Description	Data Source
Latency	ms	meter_kong_service_kong_latency meter_kong_instance_kong_latency meter_kong_endpoint_kong_latency	Latency added by Kong and enabled plugins for each service/route in Kong	Kong
Latency	ms	meter_kong_service_request_latency meter_kong_instance_request_latency meter_kong_endpoint_request_latency	Total latency incurred during requests for each service/route in Kong	Kong
Latency	ms	meter_kong_service_upstream_latency meter_kong_instance_upstream_latency meter_kong_endpoint_upstream_latency	Latency added by upstream response for each service/route in Kong	Kong

Kong Nginx Supported Metrics

Monitoring Panel	Unit	Metric Name	Description	Data Source
Nginx	count	meter_kong_service_nginx_metric_errors_total	Number of nginx-lua-prometheus errors	Kong
Nginx	count	meter_kong_service_nginx_connections_total meter_kong_instance_nginx_connections_total	Number of connections by subsystem	Kong
Nginx	count	meter_kong_service_nginx_timers meter_kong_instance_nginx_timers	Number of Nginx timers	Kong

Customizations

You can customize your own metrics/expression/dashboard panel. The metrics definition and expression rules are found in /config/otel-rules/kong. The KONG dashboard panel configurations are found in /config/ui-initialized-templates/kong.