Engineering Logs for Troubleshooting & Debugging
Problem – RAG retrieval returns empty results behind HAProxy in CI/CD pipelines During automated end‑to‑end tests a Retrieval‑Augmented Generation (RAG) service intermittently returns no documents. The symptom is observed only when the request traverses an HAProxy instance that load‑balances traffic across several identical backend replicas. Typical error messages: HAProxy log entry: <…> 0/0/0/30/30 504 0 … Read more
Problem – Intermittent DNS Resolution Failures in Docker Containers Across Multi‑Region Kubernetes AI inference services deployed as Docker containers on Amazon EKS clusters in several AWS regions (e.g., us-east-1, eu-central-1, ap-south-1) experience sporadic failures when resolving external endpoints such as model registries, third‑party APIs, or telemetry services. The failures manifest as: Go errors: dial tcp: … Read more
Problem: HAProxy “multimodal alignment” errors in a mixed‑protocol Kubernetes ingress In a GKE‑based AI platform the same HAProxy ingress is used to expose: TensorFlow Serving (gRPC over HTTP/2) FastAPI inference endpoints (HTTP/1.1) WebSocket streams (HTTP/1.1 upgrade) After a rolling update the following symptoms appeared: [WARNING] 2026/07/08 10:12:45 HA-Proxy[WARN] : content mismatch, header size exceeds payload … Read more
Problem: Nginx Fails to Bind Because a Node.js Process Holds the Desired Port In an air‑gapped deployment the nginx service is started after a Node.js micro‑service that is configured to listen on the same TCP port (commonly 80 or 443). Because the environment has no internet connectivity, developers cannot pull remote debugging tools or replace … Read more
Kubernetes CRD Validation Failure During AI Job Deployment Problem When deploying an AI training job to the staging cluster (Kubernetes v1.24) via Helm, the kubectl apply step aborts with a CRD validation error. The custom resource (AITrainingJob) is accepted by the Helm chart, but the API server rejects it, preventing the job from being created. … Read more
Problem: HAProxy Fails to Start in Docker Compose Because the Certificate Volume Is Missing or Mis‑mounted When launching a local development stack with docker-compose up, the HAProxy service aborts during initialization with errors similar to: ERROR: cannot open /etc/haproxy/certs/example.com.pem: No such file or directory HAProxy: SSL: unable to load certificate from /etc/haproxy/certs/example.com.pem (error 2) docker-compose: … Read more
Problem – Nginx Serves Stale Data After a Kubernetes Pod Update In an on‑premises data‑center, Nginx (or the Nginx Ingress Controller) is used as a reverse proxy for a micro‑services architecture. Service endpoints are discovered through the Kubernetes EndpointSlice API. After a rolling update or a pod crash, Nginx continues to forward traffic to the … Read more
Problem – HAProxy returns HTTP 429 “Too Many Requests” during local development Developers running a local HAProxy instance as a reverse proxy for several micro‑services observe intermittent 429 Too Many Requests responses. The errors appear even though traffic is generated only by integration tests, IDE live‑share sessions, or manual curl loops. Typical log lines look like: … Read more
Problem: Kubernetes Secret Rotation Failure for Multi‑GPU Training Pods In a production AI training platform, each training job runs in a pod that requests multiple GPUs. Access to the GPU resource provider (e.g., NVIDIA GPU Cloud, a proprietary licensing server, or a cloud‑native GPU quota service) is gated by short‑lived credentials stored in a Secret. … Read more
Problem: NodePort conflicts during rolling updates During a rolling update of a Deployment that exposes a Service of type NodePort, new Pods are scheduled while the old Pods are still running. If the Service definition specifies a static nodePort (or relies on the default allocation) and the update creates a second Service object (e.g., during … Read more