Observability

Prometheus scrape TLS handshake failure after streaming service cert rotation

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Prometheus scrape TLS handshake failure after streaming service cert rotation Problem Symptoms and impact After a scheduled certificate rotation on the real‑time streaming platform, Prometheus began reporting scrape errors for the affected endpoint: 2026-10-19T08:15:32.123Z level=error msg=”scrape failed” target=”streaming-prod.example.com:443″ err=”Get \”https://streaming-prod.example.com/metrics\”: remote error: tls: handshake failure” 2026-10-19T08:15:32.124Z level=error msg=”scrape failed” target=”streaming-prod.example.com:443″ err=”connection reset by peer” Prometheus … Read more

GPU OOM errors during model training after Prometheus alert in sandbox

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Problem During iterative development in the shared sandbox, data‑science engineers observed frequent GPU out‑of‑memory (OOM) failures when launching PyTorch training jobs. The failures coincided with a Prometheus alert that fired on the gpu_memory_usage_bytes metric exceeding a static threshold. The alert itself did not trigger any remediation, and the training jobs aborted with the following error … Read more

Loki query parse error from AI query builder in Grafana

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Problem In a development sandbox the AI‑powered query builder integrated with Grafana produces Loki queries that fail at execution time. The UI shows a “filter expression parse error” and the Loki server returns syntax‑related error messages such as: parse error at line 1: unexpected token “=” near “app=frontend” The failure occurs only for queries generated … Read more

Prometheus image pull failure on edge node after registry auth error

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Problem – Prometheus Fails to Pull Its Image on an Edge Node An edge‑computing node that runs a lightweight Kubernetes distribution (e.g., K3s) attempts to start the prometheus pod. The pod remains in ImagePullBackOff and the node reports a registry authentication error combined with intermittent network timeouts. $ kubectl get pod -n monitoring prometheus-0 -o … Read more

Prometheus model inference failure after tokenizer encoding error in hybrid Kubernetes

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Problem In a hybrid Kubernetes deployment (on‑premise + AWS EKS) the Prometheus model service intermittently crashes during inference. The failure manifests as a RuntimeError: token ids out of range exception raised by the model’s PyTorch inference loop. The same input text that succeeds on a pure‑cloud cluster fails when the request is routed to a … Read more

Grafana panel duplicate data after RAG chunk overlap in A/B test

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Problem: Grafana panels show duplicated or missing data during A/B testing of dashboard versions During a staged rollout of two dashboard variants (A and B) using Grafana’s feature‑flag based A/B testing, operators observed the following symptoms: Prometheus‑based time‑series panels display each metric twice, inflating KPI values by ~100%. Loki log panels contain duplicate log entries … Read more

Prometheus scrape target creation failure for TensorFlow Serving after Helm upgrade

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Problem Description After upgrading the tf-serving Helm chart, Prometheus stopped collecting latency and throughput metrics from TensorFlow Serving pods. The Prometheus server logs contain entries such as: scrape target creation failed: connection refused (target: http://10.1.2.3:8501/metrics) no endpoints found for service “tf-serving” in namespace “ml” – check ServiceMonitor selector error reading body: EOF while scraping TensorFlow … Read more

Prometheus scrape 401 token limit exceeded during canary rollout

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Problem – 401 Token Limit Exceeded During Canary Scrape During a staged rollout of a new microservice, Prometheus began reporting scrape failures with the following error: error scraping target “http://service-canary:9090/metrics”: unexpected status code 401 Unauthorized (token limit exceeded) Additional log entries from the Prometheus server process show the token acquisition step failing: 2024-08-12T14:23:07Z level=error msg=”failed to fetch bearer … Read more

Prometheus nightly batch aborts due to RAG prompt placeholder not substituted

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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

Grafana dashboard query latency spikes over 8000ms with PromQL aggregations

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Problem Description Grafana dashboards that visualize real‑time model inference latency and GPU utilization are experiencing intermittent rendering latency spikes that exceed 8000 ms. The symptoms observed in the UI and logs are: Panel data request timed out after 8000 ms (Grafana UI). Grafana logs contain datasource query timeout and Failed to query datasource: context deadline exceeded. Prometheus … Read more