feat: add option to disable summary collection in routeMetrics config

README.md

@@ -141,6 +141,7 @@ See for details [docs](docs/api/fastify-metrics.imetricspluginoptions.md)
 | Property                                                                                    | Type                                                                                          | Default Value                           |
 | ------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------- | --------------------------------------- |
 | [enabled?](./docs/fastify-metrics.iroutemetricsconfig.enabled.md)                           | boolean                                                                                       | `true`                                  |
+| [enableSummaries?](./docs/fastify-metrics.iroutemetricsconfig.enablesummaries.md)           | boolean                                                                                       | `true`                                  |
 | [groupStatusCodes?](./docs/fastify-metrics.iroutemetricsconfig.groupstatuscodes.md)         | boolean                                                                                       | `false`                                 |
 | [invalidRouteGroup?](./docs/fastify-metrics.iroutemetricsconfig.invalidroutegroup.md)       | string                                                                                        | `'__unknown__'`                         |
 | [methodBlacklist?](./docs/fastify-metrics.iroutemetricsconfig.methodblacklist.md)           | readonly string\[\]                                                                           | `['HEAD','OPTIONS','TRACE','CONNECT',]` |
@@ -205,7 +206,7 @@ await app.register(metricsPlugin, {
 
 ### HTTP routes metrics in Prometheus
 
-The following table shows what metrics will be available in Prometheus. Note suffixes like `_bucket`, `_sum`, `_count` are added automatically.
+The following table shows what metrics will be available in Prometheus. Note suffixes like `_bucket`, `_sum`, `_count` are added automatically and `summary` type metrics will only be available if `{ routeMetrics: { enableSummaries: true } }`
 
 | metric                                 | labels                           | description                   |
 | -------------------------------------- | -------------------------------- | ----------------------------- |

package.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/package.json",
   "name": "fastify-metrics",
-  "version": "10.3.3",
+  "version": "10.4.0",
   "description": "Prometheus metrics exporter for Fastify",
   "keywords": [
     "fastify-plugin",

src/__tests__/route-metrics.spec.ts

@@ -626,4 +626,61 @@ describe('route metrics', () => {
       );
     });
   });
+
+  describe(`{ routeMetrics: { enableSummaries: false } }`, () => {
+    let app = fastify();
+
+    afterEach(async () => {
+      await app.close();
+    });
+
+    beforeEach(async () => {
+      app = fastify();
+
+      await app.register(fastifyPlugin, {
+        endpoint: '/metrics',
+        routeMetrics: {
+          enabled: true,
+          enableSummaries: false,
+          customLabels: {
+            url: (request: FastifyRequest) => request.url,
+          },
+        },
+      });
+      app.get('*', async (_request, reply) => {
+        await reply.send('foo');
+      });
+      await app.ready();
+    });
+
+    test('summaries are not collected', async () => {
+      await expect(
+        app.inject({
+          method: 'GET',
+          url: '/test',
+        })
+      ).resolves.toBeDefined();
+
+      const metrics = await app.inject({
+        method: 'GET',
+        url: '/metrics',
+      });
+
+      expect(typeof metrics.payload).toBe('string');
+
+      const lines = metrics.payload.split('\n');
+
+      expect(lines).toEqual(
+        expect.arrayContaining([
+          'http_request_duration_seconds_count{method="GET",route="*",status_code="200",url="/test"} 1',
+        ])
+      );
+
+      expect(lines).toEqual(
+        expect.not.arrayContaining([
+          'http_request_summary_seconds_count{method="GET",route="*",status_code="200",url="/test"} 1',
+        ])
+      );
+    });
+  });
 });

src/fastify-metrics.ts

@@ -42,6 +42,7 @@ export const DEFAULT_OPTIONS: IMetricsPluginOptions = {
   clearRegisterOnInit: false,
   routeMetrics: {
     enabled: true,
+    enableSummaries: true,
   },
   defaultMetrics: {
     enabled: true,
@@ -352,7 +353,9 @@ export class FastifyMetrics implements IFastifyMetrics {
           [this.routeMetrics.labelNames.status]: statusCode,
           ...this.collectCustomLabels(request, reply),
         };
-        metrics.sum(labels);
+        if (!(this.options.routeMetrics.enableSummaries === false)) {
+          metrics.sum(labels);
+        }
         metrics.hist(labels);
 
         done();

src/types.ts

@@ -158,10 +158,17 @@ export interface IRouteMetricsConfig {
   /**
    * Enables collection of fastify routes metrics response time.
    *
-   * @defaultValue `false`
+   * @defaultValue `true`
    */
   enabled?: boolean;
 
+  /**
+   * Enables computation of summaries for response times.
+   *
+   * @defaultValue 'true'
+   */
+  enableSummaries?: boolean;
+
   /**
    * Collect metrics only for registered routes. If `false`, then metrics for
    * unknown routes `/unknown-unregistered-route` will be collected as well.