Engineering Logs for Troubleshooting & Debugging
Jordan Lee 
Problem – Nightly RAG Batch Jobs Abort with Unsubstituted Prompt Placeholders The nightly batch pipeline that drives large‑scale Retrieval‑Augmented Generation (RAG) for reporting is failing. Each run aborts with a non‑zero exit code and the generated CSV contains malformed or empty fields. The primary symptom is a rendering error where template variables such as {{user_query}}, … Read more
TGI checkpoint storage class not found after A/B deployment Problem During an A/B testing rollout of Text Generation Inference (TGI) instances, the newly created replica fails to start and logs an error similar to: Failed to load checkpoint: storage class “fast-ssd” not found Other observed symptoms include: Pod tgi-a-12345 stays in Pending state. kubectl describe … Read more
Problem When deploying a Mistral AI inference job through a Knative Eventing pipeline, the custom resource (CR) creation fails with a validation error from the Kubernetes API server: error: admission webhook “mistral-ai-validation.k8s.io” denied the request: spec.modelVersion: Required value: missing required field “spec.modelVersion” spec.resources.limits.cpu: Invalid value: “500m”: must be an integer spec.parameters: Additional property foo is not … Read more
Problem – Malformed Function‑Calling JSON from Gemini in an Air‑Gapped Deployment When calling a Gemini model deployed on‑premises behind an air‑gap, the client receives a response that cannot be parsed as JSON. Typical error messages include: JSONDecodeError: Expecting ‘,’ delimiter – trailing commas or missing quotes. JSONDecodeError: Unexpected token ‘<‘ at position 0 – HTML … Read more
Problem – Inference Queue Backlog During CI/CD Pipeline Execution Symptoms and Impact During automated testing and deployment steps, Haystack inference calls start to time out. Typical log excerpts look like: 2024-08-24 12:03:45,212 [celery.worker] ERROR QueueFullError: Inference queue is full (maxsize=100) 2024-08-24 12:03:48,019 [haystack.client] ERROR TimeoutError: Inference request timed out after 30 seconds 2024-08-24 12:04:01,877 [celery.worker] … Read more
Problem – Redis pod stuck pending PVC on an edge node after node reboot A Redis StatefulSet deployed to an edge‑computing node fails to start. The pod remains in Pending because its PersistentVolumeClaim (redis-data) never becomes Bound. The symptom blocks data persistence and makes the Redis service unavailable. Typical pod description: kubectl describe pod redis-0 … Read more
Problem The RAG (Retrieval‑Augmented Generation) pipeline in the Qwen service started returning incomplete answers after the embedding model was upgraded from text‑embedding‑ada‑002 to qwen‑embedding‑v2. The most visible symptom was that the query decomposition stage produced either malformed sub‑queries or no sub‑queries at all, causing downstream vector search to return empty result sets. The issue manifested … Read more
Problem – Runtime error: temperature value out of 0‑1 range During a fine‑tuning run of a Mistral model the training script aborts after a few epochs with an exception similar to: ValueError: temperature must be in the range [0.0, 1.0], got 1.3 Typical symptoms observed in the logs: Trainer initialization succeeds, then validate_sampling_params raises. Training … Read more
Problem Description Symptoms and Impact After upgrading the Docker image to CUDA 12.4, vLLM v0.6.3 started emitting malformed JSON for function‑calling prompts. The downstream FastAPI gateway receives a truncated or syntactically invalid JSON payload, which triggers json.JSONDecodeError exceptions and causes request drops. Log snippet from a worker thread: INFO vllm.engine.output_parser – Received partial JSON: {“name”: “search”, “parameters”: … Read more
RAG Pipeline Chunk Overlap Causing Duplicate Context Injection in Kubernetes Problem The Retrieval‑Augmented Generation (RAG) service deployed on a GPU‑accelerated Kubernetes cluster began exhibiting: Excessive token duplication in the vector store, leading to inflated embedding counts. Memory pressure on A100/H100 pods, resulting in OOMKilled restarts. Embedding latency spikes (>30 s) and a 40 % drop in retrieval … Read more