HaproxyServerConnectionErrors #

Too many connection errors to {{ $labels.server }} server (> 100 req/s). Request throughput may be too high.

alert: HaproxyServerConnectionErrors
annotations:
  description: |-
    Too many connection errors to {{ $labels.server }} server (> 100 req/s). Request throughput may be too high.
      VALUE = {{ $value }}
      LABELS = {{ $labels }}    
  runbook: https://srerun.github.io/prometheus-alerts/runbooks/haproxy-exporter-v1/haproxyserverconnectionerrors/
  summary: HAProxy server connection errors (instance {{ $labels.instance }})
expr: sum by (server) (rate(haproxy_server_connection_errors_total[1m])) > 100
for: 0m
labels:
  severity: critical

Meaning #

The HaproxyServerConnectionErrors alert is triggered when the total number of connection errors to a specific HAProxy server exceeds 100 requests per second over a 1-minute period. This indicates that the server is experiencing difficulties handling incoming requests, which may lead to request loss or slow responses.

Impact #

• High request latency or loss due to connection errors
• Potential impact on application performance and user experience
• Inability to handle increased traffic or load, leading to potential service unavailability

Diagnosis #

To diagnose the root cause of the issue, follow these steps:

1. Check the HAProxy server logs for error messages related to connection errors
2. Investigate the server’s resource utilization (CPU, memory, and disk usage) to identify potential bottlenecks
3. Verify that the server is properly configured and optimized for the current workload
4. Review the application’s traffic patterns and request rates to identify potential spikes or anomalies
5. Check for any recent changes to the server configuration, application code, or infrastructure that may be contributing to the issue

Mitigation #

To mitigate the issue, follow these steps:

1. Immediate:
   • Reduce the request rate to the affected server by load-balancing or throttling requests
   • Implement a temporary fix to reduce the error rate, such as increasing the server’s resource allocation or adjusting the server’s configuration
2. Short-term:
   • Investigate and resolve any underlying issues causing the connection errors (e.g., network connectivity problems, server misconfiguration)
   • Optimize the server’s configuration for better performance and resource utilization
   • Consider implementing connection error tracking and alerting to detect issues earlier
3. Long-term:
   • Implement sustainable solutions to handle increased traffic, such as auto-scaling, load balancing, or content delivery networks (CDNs)
   • Perform regular performance and stress tests to identify potential bottlenecks and weaknesses
   • Develop a comprehensive monitoring and alerting strategy to detect issues proactively