Struct RelabeledMetricVec

pub struct RelabeledMetricVec<M> {
    relabel_threshold: MetricLevel,
    metric_level: MetricLevel,
    metric: M,
    relabel_num: usize,
}

For all Relabeled*Vec below,

• when metric_level <= relabel_threshold, they behave exactly the same as their inner metric.
• when metric_level > relabel_threshold, the first relabel_num labels are rewrite to “” when calling with_label_values. That’s means the metric vec is aggregated into a single metric.

These wrapper classes add a metric_level field to corresponding metric. We could have use one single struct to represent all MetricVec<T: MetricVecBuilder>, rather than specializing them one by one. However, that’s undoable because prometheus crate doesn’t export MetricVecBuilder implementation like HistogramVecBuilder.

Note

CAUTION! Relabelling might cause expected result!

For counters (including histogram because it uses counters internally), it’s usually natural to sum up the count from multiple labels.

For the rest (such as Gauge), the semantics becomes “any/last of the recorded value”. Please be cautious.

Fields

relabel_threshold: MetricLevel

metric_level: MetricLevel

metric: M

relabel_num: usize

The first relabel_num labels will be relabeled to empty string

For example, if relabel_num is 1, and the input labels are ["actor_id", "fragment_id", "table_id"], when threshold is reached, the label values will be ["", "<original_fragment_id>", "<original_table_id>"].

Implementations

impl<M> RelabeledMetricVec<M>

pub fn with_metric_level( metric_level: MetricLevel, metric: M, relabel_threshold: MetricLevel, ) -> Self

pub fn with_metric_level_relabel_n( metric_level: MetricLevel, metric: M, relabel_threshold: MetricLevel, relabel_num: usize, ) -> Self

impl<T: MetricVecBuilder> RelabeledMetricVec<MetricVec<T>>

pub fn with_label_values(&self, vals: &[&str]) -> T::M

impl<T: MetricVecBuilder, const N: usize> RelabeledMetricVec<LabelGuardedMetricVec<T, N>>

pub fn with_guarded_label_values( &self, vals: &[&str; N], ) -> LabelGuardedMetric<T::M, N>

Trait Implementations

impl<M: Clone> Clone for RelabeledMetricVec<M>

fn clone(&self) -> RelabeledMetricVec<M>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Collector> Collector for RelabeledMetricVec<T>

fn desc(&self) -> Vec<&Desc>

Return descriptors for metrics.

fn collect(&self) -> Vec<MetricFamily>

Collect metrics.

impl<M: Debug> Debug for RelabeledMetricVec<M>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.