diff options
Diffstat (limited to 'vendor/go.opentelemetry.io/otel/sdk/metric/doc.go')
| -rw-r--r-- | vendor/go.opentelemetry.io/otel/sdk/metric/doc.go | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/vendor/go.opentelemetry.io/otel/sdk/metric/doc.go b/vendor/go.opentelemetry.io/otel/sdk/metric/doc.go index 90a4ae16c..0f3b9d623 100644 --- a/vendor/go.opentelemetry.io/otel/sdk/metric/doc.go +++ b/vendor/go.opentelemetry.io/otel/sdk/metric/doc.go @@ -39,6 +39,30 @@ // Meter.RegisterCallback and Registration.Unregister to add and remove // callbacks without leaking memory. // +// # Cardinality Limits +// +// Cardinality refers to the number of unique attributes collected. High cardinality can lead to +// excessive memory usage, increased storage costs, and backend performance issues. +// +// Currently, the OpenTelemetry Go Metric SDK does not enforce a cardinality limit by default +// (note that this may change in a future release). Use [WithCardinalityLimit] to set the +// cardinality limit as desired. +// +// New attribute sets are dropped when the cardinality limit is reached. The measurement of +// these sets are aggregated into +// a special attribute set containing attribute.Bool("otel.metric.overflow", true). +// This ensures total metric values (e.g., Sum, Count) remain correct for the +// collection cycle, but information about the specific dropped sets +// is not preserved. +// +// Recommendations: +// +// - Set the limit based on the theoretical maximum combinations or expected +// active combinations. The OpenTelemetry Specification recommends a default of 2000. +// - A too high of a limit increases worst-case memory overhead in the SDK and may cause downstream +// issues for databases that cannot handle high cardinality. +// - A too low of a limit causes loss of attribute detail as more data falls into overflow. +// // See [go.opentelemetry.io/otel/metric] for more information about // the metric API. // |