Config

The Prometheus metrics library provides multiple options how to override configuration at runtime:

Properties file
System properties

Future releases will add more options, like configuration via environment variables.

Example:

io.prometheus.exporter.httpServer.port = 9401

The property above changes the port for the HTTPServer exporter to 9401.

Properties file: Add the line above to the properties file.
System properties: Use the command line parameter -Dio.prometheus.exporter.httpServer.port=9401 when starting your application.

Location of the Properties File

The properties file is searched in the following locations:

/prometheus.properties in the classpath. This is for bundling a properties file with your application.
System property -Dprometheus.config=/path/to/prometheus.properties.
Environment variable PROMETHEUS_CONFIG=/path/to/prometheus.properties.

Metrics Properties

Name	Javadoc	Note
io.prometheus.metrics.exemplarsEnabled	Counter.Builder.withExemplars()	(1) (2)
io.prometheus.metrics.histogramNativeOnly	Histogram.Builder.nativeOnly()	(2)
io.prometheus.metrics.histogramClassicOnly	Histogram.Builder.classicOnly()	(2)
io.prometheus.metrics.histogramClassicUpperBounds	Histogram.Builder.classicUpperBounds()	(3)
io.prometheus.metrics.histogramNativeInitialSchema	Histogram.Builder.nativeInitialSchema()
io.prometheus.metrics.histogramNativeMinZeroThreshold	Histogram.Builder.nativeMinZeroThreshold()
io.prometheus.metrics.histogramNativeMaxZeroThreshold	Histogram.Builder.nativeMaxZeroThreshold()
io.prometheus.metrics.histogramNativeMaxNumberOfBuckets	Histogram.Builder.nativeMaxNumberOfBuckets()
io.prometheus.metrics.histogramNativeResetDurationSeconds	Histogram.Builder.nativeResetDuration()
io.prometheus.metrics.summaryQuantiles	Summary.Builder.quantile(double)	(4)
io.prometheus.metrics.summaryQuantileErrors	Summary.Builder.quantile(double, double)	(5)
io.prometheus.metrics.summaryMaxAgeSeconds	Summary.Builder.maxAgeSeconds()
io.prometheus.metrics.summaryNumberOfAgeBuckets	Summary.Builder.numberOfAgeBuckets()

Notes

(1) withExemplars() and withoutExemplars() are available for all metric types, not just for counters
(2) Boolean value. Format: property=true or property=false.
(3) Comma-separated list. Example: .005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10.
(4) Comma-separated list. Example: 0.5, 0.95, 0.99.
(5) Comma-separated list. If specified, the list must have the same length as io.prometheus.metrics.summaryQuantiles. Example: 0.01, 0.005, 0.005.

There’s one special feature about metric properties: You can set a property for one specific metric only by specifying the metric name. Example: Let’s say you have a histogram named latency_seconds.

io.prometheus.metrics.histogramClassicUpperBounds = 0.2, 0.4, 0.8, 1.0

The line above sets histogram buckets for all histograms. However:

io.prometheus.metrics.latency_seconds.histogramClassicUpperBounds = 0.2, 0.4, 0.8, 1.0

The line above sets histogram buckets only for the histogram named latency_seconds.

This works for all Metrics properties.

Exemplar Properties

Name	Javadoc	Note
io.prometheus.exemplars.minRetentionPeriodSeconds	ExemplarsProperties.getMinRetentionPeriodSeconds()
io.prometheus.exemplars.maxRetentionPeriodSeconds	ExemplarsProperties.getMaxRetentionPeriodSeconds()
io.prometheus.exemplars.sampleIntervalMilliseconds	ExemplarsProperties.getSampleIntervalMilliseconds()

Exporter Properties

Name	Javadoc	Note
io.prometheus.exporter.includeCreatedTimestamps	ExporterProperties.getIncludeCreatedTimestamps()	(1)
io.prometheus.exporter.exemplarsOnAllMetricTypes	ExporterProperties.getExemplarsOnAllMetricTypes()	(1)

(1) Boolean value, true or false. Default see Javadoc.

Exporter Filter Properties

Name	Javadoc	Note
io.prometheus.exporter.filter.metricNameMustBeEqualTo	ExporterFilterProperties.getAllowedMetricNames()	(1)
io.prometheus.exporter.filter.metricNameMustNotBeEqualTo	ExporterFilterProperties.getExcludedMetricNames()	(2)
io.prometheus.exporter.filter.metricNameMustStartWith	ExporterFilterProperties.getAllowedMetricNamePrefixes()	(3)
io.prometheus.exporter.filter.metricNameMustNotStartWith	ExporterFilterProperties.getExcludedMetricNamePrefixes()	(4)

(1) Comma sparated list of allowed metric names. Only these metrics will be exposed.
(2) Comma sparated list of excluded metric names. These metrics will not be exposed.
(3) Comma sparated list of prefixes. Only metrics starting with these prefixes will be exposed.
(4) Comma sparated list of prefixes. Metrics starting with these prefixes will not be exposed.

Exporter HTTPServer Properties

Name	Javadoc	Note
io.prometheus.exporter.httpServer.port	HTTPServer.Builder.port()

Exporter OpenTelemetry Properties

Name	Javadoc	Note
io.prometheus.exporter.opentelemetry.protocol	OpenTelemetryExporter.Builder.protocol()	(1)
io.prometheus.exporter.opentelemetry.endpoint	OpenTelemetryExporter.Builder.endpoint()
io.prometheus.exporter.opentelemetry.headers	OpenTelemetryExporter.Builder.headers()	(2)
io.prometheus.exporter.opentelemetry.intervalSeconds	OpenTelemetryExporter.Builder.intervalSeconds()
io.prometheus.exporter.opentelemetry.timeoutSeconds	OpenTelemetryExporter.Builder.timeoutSeconds()
io.prometheus.exporter.opentelemetry.serviceName	OpenTelemetryExporter.Builder.serviceName()
io.prometheus.exporter.opentelemetry.serviceNamespace	OpenTelemetryExporter.Builder.serviceNamespace()
io.prometheus.exporter.opentelemetry.serviceInstanceId	OpenTelemetryExporter.Builder.serviceInstanceId()
io.prometheus.exporter.opentelemetry.serviceVersion	OpenTelemetryExporter.Builder.serviceVersion()
io.prometheus.exporter.opentelemetry.resourceAttributes	OpenTelemetryExporter.Builder.resourceAttributes()	(3)

(1) Protocol can be grpc or http/protobuf.
(2) Format: key1=value1,key2=value2
(3) Format: key1=value1,key2=value2

Many of these attributes can alternatively be configured via OpenTelemetry environment variables, like OTEL_EXPORTER_OTLP_ENDPOINT. The Prometheus metrics library has support for OpenTelemetry environment variables. See Javadoc for details.