chore: add Prometheus alerts for HAProxy v2

ref #87

_data/rules.yml

@@ -1070,12 +1070,84 @@ groups:
           - name: Embedded exporter (HAProxy >= v2)
             doc_url: https://github.com/haproxy/haproxy/tree/master/contrib/prometheus-exporter
             rules:
+              - name: HAProxy high HTTP 4xx error rate backend
+                description: Too many HTTP requests with status 4xx (> 5%) on backend {{ $labels.fqdn }}/{{ $labels.backend }}
+                query: '((sum by (server) (rate(haproxy_server_http_responses_total{code="4xx"}[1m])) / sum by (proxy) (rate(haproxy_server_http_responses_total[1m]))) * 100) > 5'
+                severity: critical
+                for: 1m
+              - name: HAProxy high HTTP 4xx error rate backend
+                description: Too many HTTP requests with status 5xx (> 5%) on backend {{ $labels.fqdn }}/{{ $labels.backend }}
+                query: ((sum by (server) (rate(haproxy_server_http_responses_total{code="5xx"}[1m])) / sum by (proxy) (rate(haproxy_server_http_responses_total[1m]))) * 100) > 5
+                severity: critical
+                for: 1m
+              - name: HAProxy high HTTP 4xx error rate server
+                description: Too many HTTP requests with status 4xx (> 5%) on server {{ $labels.server }}
+                query: ((sum by (server) (rate(haproxy_server_http_responses_total{code="4xx"}[1m])) / sum by (proxy) (rate(haproxy_server_http_responses_total[1m]))) * 100) > 5
+                severity: critical
+                for: 1m
+              - name: HAProxy high HTTP 5xx error rate server
+                description: Too many HTTP requests with status 5xx (> 5%) on server {{ $labels.server }}
+                query: ((sum by (server) (rate(haproxy_server_http_responses_total{code="5xx"}[1m])) / sum by (proxy) (rate(haproxy_server_http_responses_total[1m]))) * 100) > 5
+                severity: critical
+                for: 1m
+              - name: HAProxy server response errors
+                description: Too many response errors to {{ $labels.server }} server (> 5%).
+                query: (sum by (server) (rate(haproxy_server_response_errors_total[1m])) / sum by (server) (rate(haproxy_server_http_responses_total[1m]))) * 100 > 5
+                severity: critical
+                for: 1m
+              - name: HAProxy backend connection errors
+                description: Too many connection errors to {{ $labels.fqdn }}/{{ $labels.backend }} backend (> 100 req/s). Request throughput may be to high.
+                query: (sum by (proxy) (rate(haproxy_backend_connection_errors_total[1m]))) > 100
+                severity: critical
+                for: 1m
+              - name: HAProxy server connection errors
+                description: Too many connection errors to {{ $labels.server }} server (> 100 req/s). Request throughput may be to high.
+                query: (sum by (proxy) (rate(haproxy_backend_connection_errors_total[1m]))) > 100
+                severity: critical
+              - name: HAProxy backend max active session
+                description: HAproxy backend {{ $labels.fqdn }}/{{ $labels.backend }} is reaching session limit (> 80%).
+                query: avg_over_time(((sum by (proxy) (haproxy_server_max_sessions)) / (sum by (proxy) (haproxy_server_limit_sessions))) [2m]) * 100 > 80
+                severity: warning
+                for: 2m
+              - name: HAProxy pending requests
+                description: Some HAProxy requests are pending on {{ $labels.fqdn }}/{{ $labels.backend }} backend
+                query: sum by (proxy) haproxy_backend_current_queue > 0
+                severity: warning
+                for: 2m
+              - name: HAProxy HTTP slowing down
+                description: Average request time is increasing
+                query: avg by (proxy) (haproxy_backend_max_total_time_seconds) > 1
+                severity: warning
+                for: 1m
+              - name: HAProxy retry high
+                description: High rate of retry on {{ $labels.fqdn }}/{{ $labels.backend }} backend
+                query: sum by (proxy) (rate(haproxy_backend_retry_warnings_total[1m])) > 10
+                severity: warning
+                for: 2m
+              - name: HAProxy proxy down
+                description: HAProxy proxy is down
+                query: haproxy_backend_up == 0
+                severity: critical
+              - name: HAProxy server down
+                description: HAProxy backend is down
+                query: haproxy_backend_active_servers == 0
+                severity: critical
+              - name: HAProxy frontend security blocked requests
+                description: HAProxy is blocking requests for security reason
+                query: rate(sum by (proxy) (haproxy_frontend_denied_connections_total)) > 10
+                severity: warning
+                for: 2m
+              - name: HAProxy server healthcheck failure
+                description: Some server healthcheck are failing on {{ $labels.server }}
+                query: increase(haproxy_server_check_failures_total[1m]) > 0
+                severity: warning
+                for: 1m
           - name: prometheus/haproxy_exporter (HAProxy < v2)
             doc_url: https://github.com/prometheus/haproxy_exporter
             rules:
               - name: HAProxy down
                 description: HAProxy down
-                query: 'haproxy_up == 0'
+                query: "haproxy_up == 0"
                 severity: critical
               - name: HAProxy high HTTP 4xx error rate backend
                 description: Too many HTTP requests with status 4xx (> 5%) on backend {{ $labels.fqdn }}/{{ $labels.backend }}