# Metric cardinality limits in OpenTelemetry: a practical guide

DevFeed: [Metric cardinality limits in OpenTelemetry: a practical guide](<https://devfeed.tech/articles/metric-cardinality-limits-in-opentelemetry-a-practical-guide-32566.md>)

Original publisher: [Read original article](<https://opentelemetry.io/blog/2026/cardinality-limits-in-opentelemetry/>)

Author: OpenTelemetry Authors; Docs CC BY

Published: 2026-08-06T07:43:47Z

Content type: article

Language: en

Sources: [Blog on OpenTelemetry](<https://devfeed.tech/sources/blog-on-opentelemetry.md>)

Topics: [OpenTelemetry](<https://devfeed.tech/topics/opentelemetry.md>), [SDK](<https://devfeed.tech/topics/sdk.md>), [telemetry](<https://devfeed.tech/topics/telemetry.md>), [dashboards](<https://devfeed.tech/topics/dashboards.md>)

Tags: [cardinality](<https://devfeed.tech/tags/cardinality.md>), [dashboards](<https://devfeed.tech/tags/dashboards.md>), [filter](<https://devfeed.tech/tags/filter.md>), [guide](<https://devfeed.tech/tags/guide.md>), [memory](<https://devfeed.tech/tags/memory.md>), [metric](<https://devfeed.tech/tags/metric.md>), [metrics](<https://devfeed.tech/tags/metrics.md>), [opentelemetry](<https://devfeed.tech/tags/opentelemetry.md>), [practical](<https://devfeed.tech/tags/practical.md>), [production](<https://devfeed.tech/tags/production.md>)

## AI overview

This practical guide explains how OpenTelemetry metric cardinality limits protect process memory from unbounded growth. When a metric stream overflows, total values remain correct, but attribute-based filtering and grouping can undercount, affecting dashboards, SLOs, and alerts.

## Source excerpt

OpenTelemetry metrics are designed to be safe to use in production. One part of that safety is the cardinality limit in the metrics SDK. The limit protects your process from unbounded memory growth when a metric receives too many unique attribute combinations. That protection is useful, but it has a consequence many users do not expect: when a metric stream overflows, the total value remains correct, while queries that filter or group by attributes can undercount. This can affect dashboards, service-level objectives (SLOs), and alerts that looked correct before overflow started.