Package io.prometheus.metrics.model.snapshots

Class PrometheusNaming

java.lang.Object
io.prometheus.metrics.model.snapshots.PrometheusNaming
public class PrometheusNaming extends Object
Utility for Prometheus Metric and Label naming.

Note that this library allows dots in metric and label names. Dots will automatically be replaced with underscores in Prometheus exposition formats. However, if metrics are exposed in OpenTelemetry format the dots are retained.

  • Field Details

    • RESERVED_METRIC_NAME_SUFFIXES

      private static final String[] RESERVED_METRIC_NAME_SUFFIXES
      According to OpenMetrics _count and _sum (and _gcount, _gsum) should also be reserved metric name suffixes. However, popular instrumentation libraries have Gauges with names ending in _count. Examples:
      • Micrometer: jvm_buffer_count
      • OpenTelemetry: process_runtime_jvm_buffer_count

      We do not treat _count and _sum as reserved suffixes here for compatibility with these libraries. However, there is a risk of name conflict if someone creates a gauge named my_data_count and a histogram or summary named my_data, because the histogram or summary will implicitly have a sample named my_data_count.

  • Constructor Details

    • PrometheusNaming

      public PrometheusNaming()

  • Method Details

    • isValidMetricName

      public static boolean isValidMetricName(String name)
      Test if a metric name is valid. Rules:

      If a metric has a Unit, the metric name SHOULD end with the unit as a suffix. Note that OpenMetrics requires metric names to have their unit as suffix, and we implement this in prometheus-metrics-core. However, prometheus-metrics-model does not enforce Unit suffixes.

      Example: If you create a Counter for a processing time with Unit SECONDS, the name should be processing_time_seconds. When exposed in OpenMetrics Text format, this will be represented as two values: processing_time_seconds_total for the counter value, and the optional processing_time_seconds_created timestamp.

      Use sanitizeMetricName(String) to convert arbitrary Strings to valid metric names.

    • validateMetricName

      public static String validateMetricName(String name)
      Same as isValidMetricName(String), but produces an error message.

      The name is valid if the error message is null.

    • isValidLegacyMetricName

      public static boolean isValidLegacyMetricName(String name)

    • isValidLabelName

      public static boolean isValidLabelName(String name)

    • isValidUtf8

      private static boolean isValidUtf8(String name)

    • isValidLegacyLabelName

      public static boolean isValidLegacyLabelName(String name)

    • isValidUnitName

      public static boolean isValidUnitName(String name)
      Units may not have illegal characters, and they may not end with a reserved suffix like 'total'.

    • validateUnitName

      public static String validateUnitName(String name)
      Same as isValidUnitName(String) but returns an error message.

    • prometheusName

      public static String prometheusName(String name)
      Get the metric or label name that is used in Prometheus exposition format.
      Parameters:
      name - must be a valid metric or label name, i.e. isValidMetricName(name) or isValidLabelName(name) must be true.
      Returns:
      the name with dots replaced by underscores.

    • sanitizeMetricName

      public static String sanitizeMetricName(String metricName)
      Convert an arbitrary string to a name where isValidMetricName(name) is true.

    • sanitizeMetricName

      public static String sanitizeMetricName(String metricName, Unit unit)
      Like sanitizeMetricName(String), but also makes sure that the unit is appended as a suffix if the unit is not null.

    • sanitizeLabelName

      public static String sanitizeLabelName(String labelName)
      Convert an arbitrary string to a name where isValidLabelName(name) is true.

    • sanitizeUnitName

      public static String sanitizeUnitName(String unitName)
      Convert an arbitrary string to a name where validateUnitName(String) is null (i.e. the name is valid).
      Throws:
      IllegalArgumentException - if the unitName cannot be converted, for example if you call sanitizeUnitName("total") or sanitizeUnitName("").
      NullPointerException - if unitName is null.

    • replaceIllegalCharsInUnitName

      private static String replaceIllegalCharsInUnitName(String name)
      Returns a string with only valid unit name characters [a-zA-Z0-9_.:].

    • escapeName

      public static String escapeName(String name, EscapingScheme scheme)
      Escapes the incoming name according to the provided escaping scheme. Depending on the rules of escaping, this may cause no change in the string that is returned (especially NO_ESCAPING, which by definition is a noop). This method does not do any validation of the name.

    • needsEscaping

      public static boolean needsEscaping(String name, EscapingScheme scheme)

    • isValidLegacyChar

      static boolean isValidLegacyChar(int c, int i)

    • isValidUtf8Char

      private static boolean isValidUtf8Char(int c)