I can't speak for the creators of Prometheus, but 0 sounds like a reasonable default for anything. (Meaning it's more reasonable for a gauge to start at 0 than any other value, possibly excluding NaN.)

Gauges are typically used for measured values like temperatures or current memory usage, but also "counts" that can go up and down, like the number of concurrent requests.

September 15, 2016 - (r@turbot)4> prometheus_gauge:... ok (r@turbot)9> prometheus_gauge:reset("name"). true (r@turbot)10> prometheus_gauge:value("name"). 0 · I expected the metric to be created with the default value, and also that reset would always work....

February 5, 2021 - the gauge is then registered with a CollectorRegistry, the central store in your application for Prometheus metrics · when an item is added to the queue, the gauge can be incremented. The label value must also be passed at this point. likewise, when an item is read from the queue the gauge can be decremented, also passing the label value · By default Prometheus scrapes any configured targets once every minute.

November 6, 2023 - Use Flux to query and transform Prometheus gauge metrics stored in InfluxDB. A gauge is a metric that represents a single numerical value that can arbitrarily go up and down.

March 27, 2024 - A gauge that is registered but does not have a value set is currently set to 0 (zero). I believe this behavior to be incorrect because a gauge without a label does not work like it. const client = require('prom-client'); const gauge = ne...

April 24, 2026 - A Gauge tracks a value that can go up and down. Use it for things you sample at a point in time — active connections, queue depth, memory usage, temperature. from prometheus_client import Gauge g = Gauge('my_inprogress_requests', 'Description of gauge') g.inc() # Increment by 1 g.dec(10) # Decrement by given value g.set(4.2) # Set to a given value Constructor Gauge(name, documentation, labelnames=(), namespace='', subsystem='', unit='', registry=REGISTRY, multiprocess_mode='all') Parameter Type Default Description name str required Metric name. documentation str required Help text shown in the /metrics output and Prometheus UI. labelnames Iterable[str] () Names of labels for this metric.

February 21, 2026 - If a gauge isn’t reinitialized, Prometheus may continue scraping an outdated value or drop the time series altogether, depending on scrape timing. ... Always set gauges on startup. Don’t assume zero is the default.

A gauge metric to represent a value that can arbitrarily go up and down. The class represents the metric type gauge: https://prometheus.io/docs/concepts/metric_types/#gauge

v_labels ~label_names ~help ~namespace ~subsystem name is a family of metrics with full name namespace_subsystem_name and documentation string help. Each metric in the family will provide a value for each of the labels. The new family is registered with registry (default: CollectorRegistry.default).

Raises Prometheus.UnknownMetricError exception if a gauge for spec can't be found.<br> Raises Prometheus.InvalidMetricArityError exception if labels count mismatch. Sets the gauge identified by spec to value.

Time series that are not present until something happens are difficult to deal with, as the usual simple operations are no longer sufficient to correctly handle them. To avoid this, export a default value such as 0 for any time series you know may exist in advance.

January 30, 2026 - When dealing with gauges, timestamps become important for understanding when a value was observed. Prometheus assigns the scrape timestamp to all metrics by default, but sometimes you need to handle stale data or external timestamps.

There SHOULD be a way to initialize a given Child with the default value, usually just calling labels(). Metrics without labels MUST always be initialized to avoid problems with missing metrics. Metric names must follow the specification. As with label names, this MUST be met for uses of Gauge/Counter/Summary/Histogram and in any other Collector offered with the library.

May 8, 2019 - Hello everyone! I found that if I declare gauge_foo = Gauge( 'foo', 'Gauge Foo', registry=prometheus_registry, ) and then call push_to_gateway, it will send 0 value for the gauge to the push gateway. I gave a quick look in the code https...

July 24, 2026 - A Gauge is typically used for measured values like temperatures or current memory usage, but also "counts" that can go up and down, like the number of running goroutines. To create Gauge instances, use NewGauge. ... package main import ( "github.com/prometheus/client_golang/prometheus" ) func main() { opsQueued := prometheus.NewGauge(prometheus.GaugeOpts{ Namespace: "our_company", Subsystem: "blob_storage", Name: "ops_queued", Help: "Number of blob storage operations waiting to be processed.", }) prometheus.MustRegister(opsQueued) // 10 operations queued by the goroutine managing incoming requests.

December 27, 2019 - Info: by default Prometheus includes the configured help text and metric type for informational purposes · We can use the following query to calculate the per second rate of requests averaged over the last 5 minutes: ... Info: the rate function calculates the per second rate of increase averaged over the provided time interval. It can only be used with counters. The gauge metric type can be used for values that go down as well as up, such as current memory usage or the number of items in a queue.

Prometheus offers four core metric types to capture diverse system behaviors: Counters for tracking ever-increasing values, like the total number of exceptions thrown. Gauges for measuring fluctuating values, such as current CPU usage.

July 21, 2025 - This set() approach should be preferred for measuring stateful values like the number of items in a queue or current memory usage. By periodically checking the actual source of truth, your gauge remains stateless and self-correcting. Most Prometheus’ clients also allow you to use inc()Copy and dec()Copy for incrementing and decrementing a gauge respectively.