Package io.prometheus.metrics.model.registry

Interface Collector

All Known Implementing Classes:
Counter, CounterWithCallback, Gauge, GaugeWithCallback, Histogram, Info, Metric, MetricWithFixedMetadata, StateSet, Summary, SummaryWithCallback
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface Collector
To be registered with the Prometheus collector registry. See Overall Structure on https://prometheus.io/docs/instrumenting/writing_clientlibs/.

  • Method Details

    • collect

      MetricSnapshot collect()
      Called when the Prometheus server scrapes metrics.

    • collect

      default MetricSnapshot collect(PrometheusScrapeRequest scrapeRequest)
      Provides Collector with the details of the request issued by Prometheus to allow multi-target pattern implementation Override to implement request dependent logic to provide MetricSnapshot

    • collect

      default MetricSnapshot collect(Predicate<String> includedNames)
      Like collect(), but returns null if includedNames.test(name) is false.

      Override this if there is a more efficient way than first collecting the snapshot and then discarding it.

    • collect

      default MetricSnapshot collect(Predicate<String> includedNames, PrometheusScrapeRequest scrapeRequest)
      Like collect(Predicate), but with support for multi-target pattern.

      Override this if there is a more efficient way than first collecting the snapshot and then discarding it.

    • getPrometheusName

      default String getPrometheusName()
      This is called in two places:
      1. During registration to check if a metric with that name already exists.
      2. During scrape to check if this collector can be skipped because a name filter is present and the metric name is excluded.
      Returning null means checks are omitted (registration the metric always succeeds), and the collector is always scraped (the result is dropped after scraping if a name filter is present and the metric name is excluded).

      If your metric has a name that does not change at runtime it is a good idea to overwrite this and return the name.

      All metrics in prometheus-metrics-core override this.