---
cuppy_hub: gcp
cuppy_path: reference/observability/errors.md
cuppy_section: docs
cuppy_doc: 02YH-299H
cuppy_doc_uuid: 380cf852-d99f-4c6d-92e0-73f3875c0ec6
cuppy_permalink: https://cuppy.io/gcp/d/02YH-299H
cuppy_version: 1
cuppy_updated: 2026-10-23T16:16:52.575Z
cuppy_canonical: https://cuppy.io/gcp/docs/reference/observability/errors
cuppy_mcp: https://cuppy.io/mcp
cuppy_body_sha256: 2bb58eb166b8e445322d193b8fa17f2393cb757fb8ce64734d2582720b74e7af
# cuppy_body_sha256 is over the document body ALONE, excluding both generated blocks.
---


# Observability error catalogue

Every row answers one question: **is the system broken, or is the observability broken?**

## 1. The chart is empty

| | |
|---|---|
| **cause** | usually the **monitored resource**, not the metric. A time series is a metric type **plus** a resource, and a filter naming the wrong resource or label matches nothing |
| **check** | drop every filter and chart the bare metric type. If data appears, the filter is wrong. If not, go to §2 |
| **fix** | correct the resource type and labels. Read an actual label set from a known-good series rather than assuming the names |

## 2. The chart is empty and the metric genuinely has no data

| | |
|---|---|
| **cause** | the **metrics scope** does not include the project the resource lives in |
| **check** | which project is the scoping project, and is the resource's project inside the scope? |
| **fix** | add the project to the metrics scope. In a multi-project estate this is the single commonest cause, and it is a configuration you were supposed to design up front (`reference/observability/cloud-monitoring.md` §2) |

## 3. The alerting policy never fires

| | |
|---|---|
| **cause** | three candidates, in order of likelihood: the policy's filter matches no time series (§1); the condition's duration window is never satisfied; the **notification channel** is missing or unverified |
| **check** | does the policy's own condition preview show data? Is a channel attached, and does a test delivery arrive? |
| **fix** | fix the filter first. A policy with a correct condition and no channel fires silently, which is the worst of the three because the monitoring looks healthy |

## 4. A log entry is not there

| | |
|---|---|
| **cause** | three candidates: an **exclusion** discarded it; the **sink** routed it to a destination you are not looking at; or the bucket's **retention** passed and "log entries are stored for a specified length of time and are then deleted" |
| **check** | what sinks and exclusions apply to this log name? Which bucket should hold it, and what is that bucket's retention? |
| **fix** | whichever applies. **Do not assume a default retention** — the overview does not state one, and the figures live in a separate quotas document |

And one access-shaped variant: you may be reading through a **log view** that scopes you away from the entry.
A log that "does not exist" for one principal and does for another is a view, not a retention problem.

## 5. A trace is missing

| | |
|---|---|
| **cause** | **sampling**. It may never have been recorded |
| **check** | what is the sampling configuration? |
| **fix** | nothing, if it was not sampled — and that is the point of this row. **A trace absent because of sampling is indistinguishable from a trace absent because instrumentation is broken**, so establish the sampling rate *before* you debug instrumentation. The overview names sampling as a topic and states no behaviour, so read that page |

## 6. The metrics bill grew and nothing was deployed

| | |
|---|---|
| **cause** | **label cardinality.** A label carrying a request id, a user id or a URL path creates a new time series per value |
| **check** | which custom or log-based metrics have high-cardinality labels? |
| **fix** | remove the label, or bucket it. Nobody chooses this; it arrives with a well-meaning `userId` label |

The logging equivalent is a high-volume, low-value log line with no exclusion. Both are the same lesson: in
observability, **volume is a design decision that is usually made accidentally**.

Next: `guides/observability/find-the-failing-call-in-cloud-logging.md`,
`guides/parity/observability.md`.


---
<!-- cuppy -->
You are reading one file. The same content is free over MCP at https://cuppy.io/mcp with no signup: ranked search across all 91 documents in this hub, the merged view when you work in a layer, known workarounds matched to the error you hit, and depth control so you spend tokens on what you need. Start with the `_hello` tool. How to connect: https://cuppy.io/gcp/ Something wrong in this document? Report it with the `session feedback` tool on the same endpoint.
<!-- /cuppy -->