Observability

Prometheus scrape 401 token limit exceeded during canary rollout

by
a golden statue of a man and a woman on a boat

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

by
angel statue on brown wooden floor

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

by
a close-up of a server room

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

Prometheus token limit exceeded in cloud managed service

by
a golden statue of a man and a woman on a boat

Problem Description Several teams observed remote‑write failures from their Prometheus instances that are managed by a cloud provider (Google Cloud Managed Service for Prometheus, AWS Managed Service for Prometheus, Azure Monitor for containers). The failure manifests as HTTP 429 responses with a clear message that the token quota has been exhausted. Typical log entries include: error=”token … Read more

Prometheus remote read 429 error during cloud API rate limit

by
white angel statue on brown wooden floor

Problem – Prometheus remote read/write 429/503 errors during cloud‑API rate‑limit bursts During large‑scale LLM benchmarking runs, a fleet of GPU instances pushes telemetry (inference latency, GPU utilisation, evaluation accuracy) to a central Prometheus server. The server forwards these samples to a managed remote storage service (Google Cloud Monitoring, AWS Managed Service for Prometheus, Azure Monitor) … Read more

RAG retrieval pipeline silent failures after embedding model update

by
a golden statue of a man and a woman on a boat

Problem – Silent Retrieval Failures After Embedding Model Update The Retrieval‑Augmented Generation (RAG) pipeline started returning empty result sets while query latency dropped dramatically. No HTTP error was propagated to callers, and the existing Prometheus alerts did not fire. The symptoms appeared during a rolling deployment of a new sentence‑transformer model that changed the embedding … Read more

Grafana dashboard rendering fails with high CPU and memory usage

by
a rack of servers in a server room

Problem – Grafana Dashboard Rendering Fails Under Load In a GPU‑focused LLM training cluster (64 × A100, 48 × H100 for inference) operators observed the following symptoms after adding per‑GPU DCGM metrics and reducing the dashboard refresh interval to 5s: Grafana pod repeatedly OOMKilled: panic: runtime: out of memory HTTP 504 Gateway Timeout responses from the Grafana UI. CPU … Read more

Prometheus query error 400 Bad Request after changing label selectors

by
white angel statue on brown wooden floor

Problem: Prometheus query returns 400 Bad Request after changing label selectors After a recent change to the AI model evaluation exporter, dashboard panels that query model_inference_latency_seconds, model_accuracy, and model_tokens_total started failing with HTTP 400 responses from the Prometheus query API. The error payload typically looks like: { “status”:”error”, “errorType”:”bad_data”, “error”:”parse error at char 27: unexpected character ‘\\’ in … Read more

RAG retrieval pipeline returning empty results after metadata filter update

by
angel statue on brown wooden floor

Problem – Empty Retrieval Results After Metadata Filter Update In a hybrid‑cloud RAG (Retrieval‑Augmented Generation) deployment, the vector store retrieval pipeline began returning empty result sets and occasional query timeouts after a new metadata filter was added. The failure manifested across on‑premises and cloud‑based retrieval nodes that synchronize Pinecone/Elasticsearch indexes. Typical log excerpt: 2024-07-15T10:42:03.112Z ERROR … Read more

Prometheus query latency spikes with high-cardinality metrics

by
white angel statue on brown wooden floor

Problem Description During peak ingestion windows of a real‑time LLM inference pipeline, Prometheus query latency exceeds the 5‑second Service‑Level Objective (SLO). The most common symptom is a timeout error returned by the HTTP API: error: query timeout after 5s Dashboard panels that aggregate inference_latency_seconds by endpoint and model start rendering in 10‑12 seconds. The issue correlates … Read more