---
title: Prometheus
description: Adapter that exposes Istio metrics for ingestion by a Prometheus harvester.
location: https://istio.io/docs/reference/config/policy-and-telemetry/adapters/prometheus.html
layout: protoc-gen-docs
generator: protoc-gen-docs
aliases:
- /docs/reference/config/adapters/prometheus.html
number_of_entries: 7
---
The prometheus
adapter collects Istio metrics and makes them available to
Prometheus.
This adapter supports the metric template.
Params
Configuration format for the prometheus
adapter.
Field |
Type |
Description |
metrics |
Params.MetricInfo[] |
The set of metrics to represent in Prometheus. If a metric is defined in Istio but doesn’t have a corresponding
shape here, it will not be populated at runtime.
|
Params.MetricInfo
Describes how a metric should be represented in Prometheus.
Field |
Type |
Description |
namespace |
string |
Optional. The namespace is used as a prefix on the metric names.
An example: for a metric named “requestcount” with a namespace of “istio”,
the full metric name becomes “istiorequest_count”.
NOTE: The specificed namespace should be a prometheus-safe name. If not, the adapter
will attempt to convert the namespace to a prometheus-safe name.
NOTE: Changing the value for this will potentially impact downstream integrations
and should be used with caution.
Default value: “istio”.
|
name |
string |
Recommended. The name is used to register the prometheus metric.
It must be unique across all prometheus metrics as prometheus does not allow duplicate names.
If name is not specified a sanitized version of instance_name is used.
|
instanceName |
string |
Required. The name is the fully qualified name of the Istio metric instance
that this MetricInfo processes.
|
description |
string |
Optional. A human readable description of this metric.
|
kind |
Params.MetricInfo.Kind |
|
buckets |
Params.MetricInfo.BucketsDefinition |
For metrics with a metric kind of DISTRIBUTION, this provides a mechanism
for configuring the buckets that will be used to store the aggregated values.
This field must be provided for metrics declared to be of type DISTRIBUTION.
This field will be ignored for non-distribution metric kinds.
|
labelNames |
string[] |
The names of labels to use: these need to match the dimensions of the Istio metric.
TODO: see if we can remove this and rely on only the dimensions in the future.
|
Params.MetricInfo.BucketsDefinition
Describes buckets for DISTRIBUTION kind metrics.
Params.MetricInfo.BucketsDefinition.Explicit
Specifies a set of buckets with arbitrary widths.
There are size(bounds) + 1
(= N
) buckets. Bucket i
has the following
boundaries:
- Upper bound (
0 <= i < N-1
): bounds[i]
- Lower bound (
1 <= i < N
): bounds[i - 1]
The bounds
field must contain at least one element. If bounds
has
only one element, then there are no finite buckets, and that single
element is the common boundary of the overflow and underflow buckets.
Field |
Type |
Description |
bounds |
double[] |
The values must be monotonically increasing.
|
Params.MetricInfo.BucketsDefinition.Exponential
Specifies an exponential sequence of buckets that have a width that is
proportional to the value of the lower bound. Each bucket represents a
constant relative uncertainty on a specific value in the bucket.
There are num_finite_buckets + 2
(= N
) buckets. The two additional
buckets are the underflow and overflow buckets.
Bucket i
has the following boundaries:
- Upper bound (0 <= i < N-1):
scale * (growth_factor ^ i)
- Lower bound (1 <= i < N):
scale * (growth_factor ^ (i - 1))
Field |
Type |
Description |
numFiniteBuckets |
int32 |
Must be greater than 0.
|
growthFactor |
double |
Must be greater than 1.
|
scale |
double |
Must be greater than 0.
|
Params.MetricInfo.BucketsDefinition.Linear
Specifies a linear sequence of buckets that all have the same width
(except overflow and underflow). Each bucket represents a constant
absolute uncertainty on the specific value in the bucket.
There are num_finite_buckets + 2
(= N
) buckets. The two additional
buckets are the underflow and overflow buckets.
Bucket i
has the following boundaries:
- Upper bound (
0 <= i < N-1
): offset + (width * i)
- Lower bound (
1 <= i < N
): offset + (width * (i - 1))
Field |
Type |
Description |
numFiniteBuckets |
int32 |
Must be greater than 0.
|
width |
double |
Must be greater than 0.
|
offset |
double |
Lower bound of the first bucket.
|
Params.MetricInfo.Kind
Describes what kind of metric this is.
Name |
Description |
UNSPECIFIED |
|
GAUGE |
|
COUNTER |
|
DISTRIBUTION |
|