Out of those four requests, only one has been received. What could be the reasons for this, and how would you troubleshoot it?

When only one of four expected requests is received, several factors could be at play. First, network issues such as packet loss, DNS resolution failures, or firewall rules can drop packets before they reach the server. Second, the server or load balancer might be misconfigured, causing it to reject or drop requests (e.g., health‑check failures, rate limiting, or incorrect routing). Third, application‑level errors—such as unhandled exceptions, timeouts, or resource exhaustion—can cause the server to terminate connections prematurely. Fourth, client‑side problems (e.g., incorrect headers, authentication failures, or retry logic) can prevent the request from reaching the backend. To troubleshoot, start by inspecting server logs and monitoring metrics (CPU, memory, request latency). Use network tracing tools like tcpdump or Wireshark to confirm that packets arrive. Verify load balancer health checks and routing rules. Check firewall and security group rules to ensure the correct ports are open. If using a cloud provider, review CloudWatch or equivalent logs for dropped requests. Finally, replicate the scenario with a tool like curl or Postman to isolate whether the issue is client‑side or server‑side. By systematically validating each layer, you can pinpoint the root cause and apply the appropriate fix.