Zoho integrations rarely fail loudly. Channels expire after an hour, credits drain against a rolling window, and bulk writes return HTTP 200 while rejecting records. Here is how to instrument for absence using CloudWatch Embedded Metric Format, Loki's absent_over_time, and Grafana across both.
CloudWatch rarely fails loudly, it accumulates. This is a breakdown of the four independent meters behind the bill: ingestion, storage, Logs Insights scans and custom metric cardinality. Why the same log line gets billed three times, why log groups never expire by default, how a single dimension can multiply your metrics bill without your traffic changing, and how to attribute the spend to specific log groups before you start deleting things.
A pipeline that returns 200 is not a pipeline that works. The four decisions behind running OpenTelemetry on AWS with ADOT, the CloudWatch OTLP endpoint limits that drop data without erroring, and how to catch the failures before a colleague does.
n8n's Prometheus endpoint tells you the process is alive and busy. It does not tell you a workflow stopped producing correct output. This post walks through the three failure families that slip past a default n8n dashboard, the PromQL that catches each one, and how to close the gap with a second source of truth from the executions API.