Engineering Logs for Troubleshooting & Debugging
Problem During a planned disaster‑recovery (DR) failover, traffic for the GPT‑3.5 service was rerouted from the primary region (us-east-1) to the backup region (us-west-2). The API slice that serves the text‑completion model continued to return responses that were identical to those generated before the failover, even though the underlying model version had been updated in … Read more
Problem In a production Kubernetes deployment the ONNX Runtime inference service intermittently fails to load models stored in cloud object storage (e.g., Amazon S3, Google Cloud Storage). The failure manifests as a model‑load timeout followed by inference request timeouts. The issue appears only after a period of sustained traffic and disappears after a pod restart. … Read more
Problem: Meta LLaMA Batch Inference Fails After Intermittent Cloud API Timeouts In a production pipeline that runs large‑scale batch inference on Meta LLaMA, jobs started to abort after a few hundred input files were processed. The failure manifested as unhandled exceptions during both the input fetch phase (cloud storage read) and the result upload phase … Read more
Problem Description – Claude API Authentication Failures After Secret Rotation in Staging CI/CD During nightly staging deployments the integration test suite intermittently receives 401 Unauthorized – “Invalid API key” or 403 Forbidden – “API key expired or revoked” responses from the Anthropic Claude endpoint. The failure correlates with the automated secret‑rotation step that fetches a … Read more
Problem Description During large‑scale model evaluation runs, scripts that invoke the https://api.deepseek.com/v1/chat/completions endpoint start failing after a few seconds of sustained traffic. The most common error messages observed are: Error: connect ETIMEDOUT https://api.deepseek.com/v1/chat/completions HTTP 502 Bad Gateway – received from DeepSeek load balancer during peak load HTTP 504 Gateway Timeout – request exceeded server timeout … Read more
Kubernetes API server unreachable behind HAProxy after health‑check timeout Problem Description (Symptoms and Impact) During a routine AI inference workload deployment, the control‑plane components (controller‑manager, scheduler, kubelet) began reporting: Failed to connect to apiserver: net/http: request canceled (Client.Timeout exceeded while awaiting headers) HAProxy returned 502 errors to any client trying to reach https://k8s‑lb.example.com: SC– 502 … Read more
Problem Description The inference API service, built with FastAPI and using psycopg2/SQLAlchemy to query a PostgreSQL instance, started returning HTTP 504 timeouts after a recent firewall rule change. The API logs contain repeated connection errors such as: 2026-08-31 14:02:13,842 ERROR inference.api.handlers – could not connect to server: Connection timed out (0.00s) Is the server running … Read more
Problem During a traffic surge on the API gateway that fronts the Anthropic Claude service, response times for /v1/complete calls jumped from the typical 300‑500 ms to several seconds, occasionally reaching 30 s. The latency spike was intermittent but correlated with periods when the gateway handled thousands of concurrent requests per second. Typical error messages observed in … Read more
Problem: Gemini API Server Unreachable During High‑Concurrency Inference During fine‑tuning runs that employ a multi‑node GPU cluster with PyTorch Distributed Data Parallel (DDP), each forward pass makes a synchronous call to the Google Gemini API to obtain reward scores or augmented samples. When the inference workload exceeds a few hundred concurrent requests, the training job … Read more
Problem – Prometheus remote read/write 429/503 errors during cloud‑API rate‑limit bursts During large‑scale LLM benchmarking runs, a fleet of GPU instances pushes telemetry (inference latency, GPU utilisation, evaluation accuracy) to a central Prometheus server. The server forwards these samples to a managed remote storage service (Google Cloud Monitoring, AWS Managed Service for Prometheus, Azure Monitor) … Read more