Configurable request and resolver duration histogram metrics (#335)

services/src/modules/apollo-server-plugins/metrics.ts

@@ -6,7 +6,11 @@ import {
   GraphQLRequestListenerValidationDidEnd,
 } from 'apollo-server-plugin-base';
 import * as promClient from 'prom-client';
-import { knownApolloDirectives } from '../config';
+import {
+  knownApolloDirectives,
+  requestDurationPromHistogramBuckets,
+  resolverDurationPromHistogramBuckets,
+} from '../config';
 
 let requestDurationHistogram: promClient.Histogram<string> | undefined;
 let resolverDurationHistogram: promClient.Histogram<string> | undefined;
@@ -18,14 +22,14 @@ export function initializeMetrics(pClient: typeof promClient) {
     name: 'graphql_request_duration_seconds',
     help: 'request duration in seconds',
     labelNames: ['status', 'operationName'],
-    buckets: [0.02, 0.1, 0.5, 2, 10],
+    buckets: requestDurationPromHistogramBuckets,
   });
 
   resolverDurationHistogram = new pClient.Histogram({
     name: 'graphql_resolver_duration_seconds',
     help: 'resolver duration in seconds',
     labelNames: ['parentType', 'fieldName', 'status'],
-    buckets: [0.02, 0.1, 0.5, 2, 10],
+    buckets: resolverDurationPromHistogramBuckets,
   });
 
   requestParsingErrorCounter = new pClient.Counter({

services/src/modules/config.ts

@@ -69,3 +69,13 @@ export const knownApolloDirectives = envVarExt
   .asSet();
 
 export const corsConfiguration = envVar.get('CORS_CONFIGURATION').default({}).asJsonObject() as CorsConfiguration;
+
+export const requestDurationPromHistogramBuckets: number[] = envVarExt
+  .get('REQUEST_DURATION_PROM_HISTOGRAM_BUCKETS')
+  .default('[0.02, 0.1, 0.5, 2, 10]')
+  .asJsonArray();
+
+export const resolverDurationPromHistogramBuckets: number[] = envVarExt
+  .get('RESOLVER_DURATION_PROM_HISTOGRAM_BUCKETS')
+  .default('[0.02, 0.1, 0.5, 2, 10]')
+  .asJsonArray();

services/tests/e2e/basic/__snapshots__/metrics.spec.ts.snap

@@ -15,7 +15,6 @@ Array [
   "0.1",
   "0.5",
   "2",
-  "10",
   "+Inf",
 ]
 `;
@@ -25,8 +24,6 @@ Array [
   "0.02",
   "0.1",
   "0.5",
-  "2",
-  "10",
   "+Inf",
 ]
 `;

services/tests/e2e/basic/metrics.spec.ts

@@ -107,6 +107,7 @@ describe('Metrics', () => {
     );
     const bucketRegex = /le="(.+)",parentType=/;
     const buckets = bucketMetrics.map(m => m.match(bucketRegex)?.[1]);
+    expect(buckets).toHaveLength(4);
     expect(buckets).toMatchSnapshot();
   });
 
@@ -117,6 +118,7 @@ describe('Metrics', () => {
     );
     const bucketRegex = /le="(.+)",operationName=/;
     const buckets = bucketMetrics.map(m => m.match(bucketRegex)?.[1]);
+    expect(buckets).toHaveLength(5);
     expect(buckets).toMatchSnapshot();
   });
 

services/tests/e2e/docker-compose.yml

@@ -65,6 +65,10 @@ services:
             "publicPaths": ["/metrics", "/.well-known/apollo/server-health", "/graphql"]
           }
         }
+      REQUEST_DURATION_PROM_HISTOGRAM_BUCKETS: >
+        [0.02, 0.1, 0.5, 2]
+      RESOLVER_DURATION_PROM_HISTOGRAM_BUCKETS: >
+        [0.02, 0.1, 0.5]
     volumes:
       - ./config/plugins:/plugins:ro
       - ./config/scripts:/scripts:ro