Engineering Logs for Troubleshooting & Debugging
Problem After a primary PostgreSQL cluster outage, the standby server was promoted and the database was restored from a recent base backup. Subsequent similarity‑search queries that rely on pgvector indexes start failing with errors such as: ERROR: could not read index file “base/16384/12345”: Invalid argument DETAIL: Index “vector_idx” appears to be corrupted. HINT: Reindex the … Read more
Problem The Retrieval‑Augmented Generation (RAG) pipeline uses RabbitMQ to stream document metadata to a GPU‑accelerated inference service. After a recent change to the metadata filter, the pipeline began discarding documents that should have been included in the context set. The LLM responses became fragmented, missing critical facts, and the generation_quality_score metric dropped from 0.87 to … Read more
Problem When the API gateway scales out, the Helm release that deploys the Redis cache attempts to create additional Redis pods. The pod creation fails with an admission controller error, preventing the cache layer from meeting the traffic demand. Typical console output: $ kubectl scale deployment redis-cache –replicas=5 deployment.apps/redis-cache scaled $ kubectl get pods -w … Read more
Problem The AI inference microservice runs on GPU‑enabled nodes in a Kubernetes cluster and consumes a high‑throughput Kafka topic. After a blue‑green deployment rollout, the new (green) pods start reporting CUDA out of memory (OOM) errors, causing request failures and a cascade of consumer lag in Kafka. Typical log excerpt from a failing pod: 2026-09-28 … Read more
Problem After a scheduled rotation of the OAuth2 client secret used by Kafka producers and consumers, the applications began failing to acquire access tokens from the authorization server. The resulting authentication errors caused the following observable symptoms: Kafka client logs contain org.apache.kafka.common.errors.SaslAuthenticationException with messages such as Failed to acquire OAuth token: 401 Unauthorized. Producer metrics … Read more
RAG Document Loader Segfault After Redis Batch Load During Benchmark Problem During a high‑throughput performance benchmark of a Retrieval‑Augmented Generation (RAG) pipeline, the document loader crashes with a segmentation fault (SIGSEGV) or an out‑of‑memory (OOM) kill. The failure occurs immediately after a bulk INSERT of thousands of documents into Redis, just before the first query‑time … Read more
Problem Description During a planned disaster‑recovery (DR) failover from the primary Kafka cluster to a secondary replica, the AI model‑training data ingestion pipeline stalls. Batch jobs that consume from Kafka topics exceed their SLA and are terminated with a Job completion timeout. The underlying failure manifests as consumer‑group rebalancing timeouts and growing offset lag. Typical … Read more
Problem – Duplicate Fragments from Overlapping Chunk Inserts In an event‑driven Retrieval‑Augmented Generation (RAG) pipeline, incoming documents are split into overlapping text windows (chunks) and each chunk is stored as a vector in PostgreSQL using the pgvector extension. After a recent deployment, retrieval queries began returning multiple identical fragments, inflating similarity scores and producing noisy … Read more
Problem – Vector Index Corruption After Blue‑Green Traffic Switch During a blue‑green rollout of a streaming analytics pipeline, the new version of the service began writing vector index files (Avro‑encoded embeddings) to a compacted Kafka topic while the previous version was still running. After the traffic cut‑over, downstream consumers started failing with deserialization errors such … Read more
Problem – Timestamp Drift Between Video and LiDAR Streams on an Edge Kafka Node In a low‑power edge deployment a local Kafka broker aggregates two high‑rate topics: video‑frames – 30 fps H.264 payloads, timestamps generated by the camera firmware. lidar‑points – 10 Hz point‑cloud packets, timestamps generated by the LiDAR driver. During intermittent Wi‑Fi outages the following … Read more