Engineering Logs for Troubleshooting & Debugging
Jordan Lee 
Problem Description In a Docker‑based AI training workload orchestrated by Kubernetes, a ReplicaSet that should run multiple pods—each requesting a set of GPUs—stops scaling after the first replica. The cluster has sufficient free GPUs (e.g., a node with 8 × NVIDIA A100), but subsequent pods remain in Pending with scheduler messages such as: 0/5 nodes are available: 5 … Read more
Shard Rebalancing Fails in Docker Container on Azure VM Problem Description A distributed AI training workload runs inside a Docker container on an Azure Virtual Machine. The storage layer is sharded (e.g., Milvus, Redis Cluster, or a custom file‑system). During normal operation the coordinator attempts to relocate shards to balance load, but the operation aborts … Read more
Problem – DNS resolution failures during LangChain batch API calls When running a LangChain batch pipeline on a distributed compute cluster (Kubernetes, Ray, Azure Batch, or on‑premise HPC), the jobs intermittently abort with DNS‑related exceptions. Typical log excerpts look like: socket.gaierror: [Errno -3] Temporary failure in name resolution aiohttp.client_exceptions.ClientConnectorError: Cannot connect to host api.example.com:443 ssl:default … Read more
Problem: PostgreSQL Pod Stalls Because PVC Remains Pending A PostgreSQL container launched by a StatefulSet (or plain Deployment) cannot start. The pod events contain messages such as: Warning FailedMount 12s (x3 over 30s) kubelet MountVolume.SetUp failed for volume “postgres-data” : could not attach or mount volume: failed to find a matching node for volume and the … Read more
Problem – RAG query decomposition fails during a rolling update During a rolling update of an MLflow‑served Retrieval‑Augmented Generation (RAG) model, inference requests start returning errors such as: Failed to decompose query: embedding dimension mismatch (expected 768, got 512) CacheKeyCollisionError: Duplicate cache entry for key ‘rag_decompose:customer_id=123’ detected during rolling update ModelVersionNotFoundError: Requested version ‘2’ for … Read more
Problem – HAProxy NodePort Conflict in Kubernetes Staging In the staging environment several AI micro‑services expose a NodePort service. The HAProxy ingress controller attempts to bind each service’s NodePort on the host network interface. When two or more services request the same port, HAProxy pods repeatedly fail to start with errors such as: 2024-06-23T10:12:45Z haproxy[1]: … Read more
Problem Description Symptoms and Impact After the nightly CI/CD pipeline retrains the Mistral AI embedding model and rolls out the new container image, the /v1/hybrid-search endpoint returns noticeably different relevance scores in the production Kubernetes cluster compared to the staging cluster. Typical observations: Top‑K results differ in ordering despite identical query text. Score drift of … Read more
Problem – Frequent Pod Evictions on AMD GPU Nodes During Disaster Recovery During disaster‑recovery (DR) drills the AI training platform experiences a surge of concurrent training jobs. On clusters that use AMD MI250X GPUs the kubelet repeatedly evicts pods with the reason=OutOfmemory condition. Typical symptoms observed: Pods transition to Evicted status within minutes of the … Read more
Problem Description During high‑throughput real‑time streaming with OpenAI GPT‑4o, the inference pipeline intermittently drops the connection. The client receives HTTP 401 responses such as: Error: Invalid API Key HTTP/1.1 401 Unauthorized Content-Type: application/json { “error”: { “message”: “Invalid request: token expired”, “type”: “invalid_request_error”, “code”: “invalid_api_key” } } Log excerpts from the Python SDK show the same … Read more
ONNX Runtime RAG Reranker Timeout on Premises Server Problem Description The RAG (Retrieval‑Augmented Generation) pipeline uses an ONNX Runtime reranker model to score retrieved documents before generation. In a private data‑center deployment with limited CPU cores and memory, the reranker frequently exceeds the configured inference timeout during peak query load, returning errors such as: Error: … Read more