如何配置IP Load Balancing实现VPS按请求数阈值分流？

Hey there! Let's walk through exactly how to set up this request-threshold-based routing with OVH's IP Load Balancer to fit your needs.

Core Idea #

Your requirement boils down to threshold-triggered traffic splitting based on requests per minute: when total requests are ≤3500/min, send everything to S1; when exceeding 3500, forward only the excess traffic to S2. OVH's IPLB Traffic Rules, combined with Request Count metrics, can handle this logic perfectly.

Step-by-Step Configuration #

1. Set Up Backend Server Pool First #

Make sure S1 and S2 are already added to your IPLB's backend pool:

• Log into your OVH Management Console and navigate to your IPLB instance
• Go to the Backend Servers tab
• Add both S1 and S2, and configure health checks (like HTTP/HTTPS checks) to ensure the load balancer only sends traffic to online servers

2. Create a Request Count Rule #

First, we need a rule to track requests per minute:

• Head to the Traffic Rules tab and click Create a rule
• Select Request Count as the rule type
• Set the time window to 60 seconds (1 minute) and the threshold to 3500
• Name it something descriptive, like req_threshold_3500_per_min

3. Configure Traffic Splitting Logic #

We'll need two rules to cover your scenario, ordered by priority:

Rule 1: Route All Traffic to S1 When Under Threshold

• Create a new rule with high priority (so it matches first)
• For the match condition, select your req_threshold_3500_per_min rule, set the condition to Count < 3500
• Choose the action Forward to backend, and select the server group (or direct server) for S1

Rule 2: Route Excess Traffic to S1 When Over Threshold

• Create a second rule with lower priority than Rule 1
• For the match condition, select req_threshold_3500_per_min, set the condition to Count >= 3500
• Enable the Only forward excess traffic option (if available in your IPLB interface) — this ensures only requests beyond the 3500 threshold get sent to S2, while the first 3500 still go to S1
• Choose the action Forward to backend, and select the server group (or direct server) for S2

4. Validate the Configuration #

Test the setup to make sure it works as expected:

• Use a load testing tool like ab or wrk to send ~3000 requests/minute — verify all traffic lands on S1
• Send ~4000 requests/minute — check that S1 receives 3500 requests, and S2 gets the remaining 500

Key Notes #

• Ensure the request count rule tracks traffic for your target frontend ports (e.g., 80 for HTTP, 443 for HTTPS)
• Double-check health check configurations to avoid routing traffic to offline servers
• The "excess traffic" option is critical here — without it, all traffic would switch to S2 once the threshold is hit, which isn't what you want

内容的提问来源于stack exchange，提问作者Ghulam Akbar