Engineering Logs for Troubleshooting & Debugging
Problem An automated ETL pipeline invokes the Google Gemini API for model inference. After rotating the Google Cloud service account used for authentication, the pipeline repeatedly fails to acquire an OAuth2 access token. All subsequent Gemini requests return 401 Unauthorized errors, causing the data processing job to abort. Root Cause The failure stems from a … Read more
Kubernetes Cron Overlap Causing Concurrent GPT‑3.5 Batch Jobs Problem The nightly batch pipeline that invokes the OpenAI gpt‑3.5‑turbo model is implemented as a CronJob on a Kubernetes cluster. During several nights the pipeline failed with errors similar to: 2024-10-12T02:15:43Z ERROR rate limit exceeded for model gpt-3.5-turbo 2024-10-12T02:15:44Z INFO Retrying request after backoff… 2024-10-12T02:16:01Z FATAL job … Read more
Problem The Horizontal Pod Autoscaler (HPA) for the Claude inference service never scales out, even though the cpu utilization metric consistently exceeds the configured target (80%). Pods remain at the minimum replica count (2), CPU usage stays above 90%, and request latency grows from ~150 ms to >2 s during traffic spikes. Root Cause Investigation revealed three … Read more
Problem – Token Refresh Failure During Rolling Update of DeepSeek Inference Pods During a rolling update of the DeepSeek inference service in a Kubernetes cluster, newly scheduled pods attempt to obtain a fresh OAuth2 access token from the internal token‑issuer service. The request fails, resulting in authentication errors (HTTP 401) and dropped inference requests. The issue … Read more
Problem – Intermittent Qwen Query Latency Spikes in an On‑the‑Fly Evaluation Loop During a continuous training run, the Qwen model is invoked for on‑the‑fly evaluation after each training epoch. Most inference calls complete within ~30 ms, but occasional spikes of 300‑800 ms appear, causing the overall training step time to increase by up to 5×. The spikes … Read more
Problem – Scheduler Pod Fails to Schedule After Node‑Affinity Change The GPT‑4o inference scheduler pod remains in Pending state despite the cluster having free capacity. The issue appeared after a change to the pod’s nodeAffinity rules intended to isolate inference workloads on GPU‑enabled nodes. Observed symptoms Pod status: Pending Events from kubectl describe pod gpt4o-scheduler-xxxx … Read more
Problem – Duplicate Model Refresh Tasks During Rolling Updates During a rolling update of the Anthropic Claude service, operators observed that the model-refresh CronJob executed twice for a single refresh window. The duplicate executions caused: Increased CPU and memory pressure on the refreshed pods. Conflicting writes to the shared model cache, resulting in occasional cache … Read more
Problem – OOM During Concurrent A/B‑Test Variants of GPT‑4 Inference In production we run an A/B testing framework that sends several prompt variants to the OpenAI GPT‑4 endpoint in parallel. Under load the inference workers start throwing Memory allocation failed or CUDA out of memory exceptions, causing request failures and downstream SLA breaches. Root Cause … Read more
Gemini Scheduler Pod Placement Failure After Adding New Model Microservice Problem The Google Gemini scheduler repeatedly reports FailedScheduling for pods belonging to the newly introduced model‑service microservice. Deployments stall, and the kubectl get pods output shows pods stuck in Pending state: NAME READY STATUS RESTARTS AGE model-service-7c9f5d9d9b-abcde 0/1 Pending 0 2m30s Cluster-wide impact includes: Increased … Read more
Problem During local development of a Meta LLaMA inference pipeline that incorporates audio inputs, the process aborts with a ValueError: unsupported audio sample rate. The exception is raised when the transformers audio preprocessing utilities attempt to load WAV or MP3 files whose sample rate or channel layout does not match the model’s expectations. Typical traceback … Read more