Prometheus metrics exporter for Fastify.
This plugin uses prom-client under the hood.
This plugin also adds two http metrics for your routes:
- Requests duration histogram
- Requests duration summary
- fastify-metrics
- v3.x.x - supports
fastify-1.x
- v4.x.x - supports
fastify-2.x
prom-client-11.x
- v5.x.x - supports
fastify-2.x
prom-client-12.x
- v6.x.x - supports
fastify-3.x
- v9.x.x - supports
fastify-4.x
prom-client-14.x
- Replace route
context.config
withrouteConfig
due to deprecation in fastify v4 and removal in fastify v5. If you haddisableMetrics
option in you routeconfig
, update fastify to latest version. - Prefer
request.routeOptions.method
over deprecatedrequest.routerMethod
.
- Fastify v4 support.
- Complete config rewrite, default behaviour changed.
- Support disabling metrics in route config.
- Now collects metrics only for registered routes by default.
- Unknown routes metrics collection disabled by default.
- Removed
metrics
fromrequest
. Now it usesWeakMap
and not exposed. - Add balcklisting possibility for request methods.
- Registry overrides moved to metric configuration.
- Support overriding all Summary and Histogram options for default route metrics.
- Fastify v3 support.
- Drop node.js 8 support.
enableDefaultMetrics
- now enables only defaultprom-client
metrics. Set totrue
by default.enableRouteMetrics
- additional flag that enables route metrics. Set totrue
by default.
npm i fastify-metrics --save
pnpm i fastify-metrics --save
- Collects default server metrics (see prom-client);
- Collects route response timings
- Adds
metrics
to fastify instance for your custom metrics.
- Requires fastify
>=4.0.0
. - Node.js
>=16.0.0
.
Add it to your project like regular fastify plugin. Use register
method and pass options to it.
const fastify = require('fastify');
const app = fastify();
const metricsPlugin = require('fastify-metrics');
await app.register(metricsPlugin, { endpoint: '/metrics' });
It also exports client to fastify instance fastify.metrics.client
which you may use it in your routes.
You may create your metrics when app starts and store it in fastify.metrics
object and reuse them in multiple routes.
After calling registry.clear()
all metrics are removed from registry. In order to add them again to the registry, call fastify.mterics.initMetricsInRegistry
.
See for details docs
Property | Type | Default Value |
---|---|---|
defaultMetrics? | IDefaultMetricsConfig | { enabled: true } |
endpoint? | string | null | Fastify.RouteOptions |
'/metrics' |
name? | string | 'metrics' |
routeMetrics? | IRouteMetricsConfig | { enabled: true } |
Property | Type | Default Value |
---|---|---|
enabled? | boolean | { histogram: boolean, summary: boolean } | true |
enableSummaries? | boolean | true |
groupStatusCodes? | boolean | false |
invalidRouteGroup? | string | '__unknown__' |
methodBlacklist? | readonly string[] | ['HEAD','OPTIONS','TRACE','CONNECT',] |
overrides? | IRouteMetricsOverrides | |
registeredRoutesOnly? | boolean | true |
customLabels? | Record<string, string | ((request: FastifyRequest, reply: FastifyReply) => string)> | undefined |
routeBlacklist? | readonly (string | RegExp)[] | [] |
The enabled
configuration option can be either a boolean which enables/disables generation of both histograms and summaries, or it can be set to an object that allows you to pick individually whether you want histograms or summaries to be generated, for example:
{
...
routeMetrics: {
enabled: {
histogram: true,
summary: false
}
}
}
would result in the library only generating histograms.
You may override default metrics settings. You may provide overrides for two metrics tracking http request durations: histogram
and summary
.
const fastify = require('fastify');
const app = fastify();
const metricsPlugin = require('fastify-metrics');
await app.register(metricsPlugin, {
endpoint: '/metrics',
routeMetrics: {
overrides: {
histogram: {
name: 'my_custom_http_request_duration_seconds',
buckets: [0.1, 0.5, 1, 3, 5],
},
summary: {
help: 'custom request duration in seconds summary help',
labelNames: ['status_code', 'method', 'route'],
percentiles: [0.5, 0.75, 0.9, 0.95, 0.99],
},
},
},
});
Property | Type | Default value |
---|---|---|
getRouteLabel? | (request: FastifyRequest) => string | undefined |
method? | string | 'method' |
route? | string | 'route' |
status? | string | 'status_code' |
Property | Type | Default value |
---|---|---|
name? | string | 'http_request_summary_seconds' |
help? | string | 'request duration in seconds summary' |
percentiles? | number[] | [0.5, 0.9, 0.95, 0.99] |
Property | Type | Default value |
---|---|---|
name? | string | 'http_request_duration_seconds' |
help? | string | 'request duration in seconds' |
buckets? | number[] | [0.05, 0.1, 0.5, 1, 3, 5, 10] |
The following table shows what metrics will be available in Prometheus (subject to the enabled
configuration option). Note suffixes like _bucket
, _sum
, _count
are added automatically.
metric | labels | description |
---|---|---|
http_request_duration_seconds_count |
method , route , status_code |
Requests total count |
http_request_duration_seconds_bucket |
method , route , status_code |
Requests durations by bucket |
http_request_summary_seconds |
method , route , status_code |
Requests duration percentiles |
http_request_summary_seconds_count |
method , route , status_code |
Requests total count |
See docs.
See changelog.
- fastify-prom-client - just simple client that adds aggregated http requests metric.
Licensed under MIT.