AER: include encodedTraces only once to prevent duplicates

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### vNEXT
 
+- Apollo Engine Reporting: include encodedTraces only once to prevent duplicates with multiple instances of apollo-engine-reporting [PR #2040](https://github.com/apollographql/apollo-server/pull/2040)
 - `apollo-server-micro`: Set the `Content-type` to `text/html` for GraphQL Playground. [PR #2026](https://github.com/apollographql/apollo-server/pull/2026)
 
 ### v2.2.5

packages/apollo-engine-reporting-protobuf/.gitignore

@@ -0,0 +1,2 @@
+protobuf.d.ts
+protobuf.js

packages/apollo-engine-reporting-protobuf/package.json

@@ -5,9 +5,10 @@
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "scripts": {
-    "prepare": "npm run pbjs && npm run pbts",
-    "pbjs": "bash -c 'mkdir -p dist && pbjs --target static-module --out dist/index.js --wrap commonjs --force-number <(grep -v \"package mdg.engine.proto\" reports.proto)'",
-    "pbts": "pbts -o dist/index.d.ts dist/index.js"
+    "compile": "tsc && cp src/protobuf* dist",
+    "prepare": "npm run pbjs && npm run pbts && npm run compile",
+    "pbjs": "bash -c 'pbjs --target static-module --out src/protobuf.js --wrap commonjs --force-number <(grep -v \"package mdg.engine.proto\" reports.proto)'",
+    "pbts": "pbts -o src/protobuf.d.ts src/protobuf.js"
   },
   "repository": {
     "type": "git",

packages/apollo-engine-reporting-protobuf/src/index.ts

@@ -0,0 +1,24 @@
+import * as protobuf from './protobuf';
+
+// Override the generated protobuf Traces.encode function so that it will look
+// for Traces that are already encoded to Buffer as well as unencoded
+// Traces. This amortizes the protobuf encoding time over each generated Trace
+// instead of bunching it all up at once at sendReport time. In load tests, this
+// change improved p99 end-to-end HTTP response times by a factor of 11 without
+// a casually noticeable effect on p50 times. This also makes it easier for us
+// to implement maxUncompressedReportSize as we know the encoded size of traces
+// as we go.
+const originalTracesEncode = protobuf.Traces.encode;
+protobuf.Traces.encode = function(message, originalWriter) {
+  const writer = originalTracesEncode(message, originalWriter);
+  const encodedTraces = (message as any).encodedTraces;
+  if (encodedTraces != null && encodedTraces.length) {
+    for (let i = 0; i < encodedTraces.length; ++i) {
+      writer.uint32(/* id 1, wireType 2 =*/ 10);
+      writer.bytes(encodedTraces[i]);
+    }
+  }
+  return writer;
+};
+
+export = protobuf;

packages/apollo-engine-reporting-protobuf/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.base",
+  "compilerOptions": {
+    "rootDir": "./src",
+    "outDir": "./dist"
+  },
+  "include": ["src/**/*"],
+  "exclude": ["src/protobuf.d.ts", "src/protobuf.js"]
+}

packages/apollo-engine-reporting/src/agent.ts

@@ -17,27 +17,6 @@ import {
   GraphQLServiceContext,
 } from 'apollo-server-core/dist/requestPipelineAPI';
 
-// Override the generated protobuf Traces.encode function so that it will look
-// for Traces that are already encoded to Buffer as well as unencoded
-// Traces. This amortizes the protobuf encoding time over each generated Trace
-// instead of bunching it all up at once at sendReport time. In load tests, this
-// change improved p99 end-to-end HTTP response times by a factor of 11 without
-// a casually noticeable effect on p50 times. This also makes it easier for us
-// to implement maxUncompressedReportSize as we know the encoded size of traces
-// as we go.
-const originalTracesEncode = Traces.encode;
-Traces.encode = function(message, originalWriter) {
-  const writer = originalTracesEncode(message, originalWriter);
-  const encodedTraces = (message as any).encodedTraces;
-  if (encodedTraces != null && encodedTraces.length) {
-    for (let i = 0; i < encodedTraces.length; ++i) {
-      writer.uint32(/* id 1, wireType 2 =*/ 10);
-      writer.bytes(encodedTraces[i]);
-    }
-  }
-  return writer;
-};
-
 export interface ClientInfo {
   clientName?: string;
   clientVersion?: string;
@@ -190,8 +169,8 @@ export class EngineReportingAgent<TContext = any> {
       this.report.tracesPerQuery[statsReportKey] = new Traces();
       (this.report.tracesPerQuery[statsReportKey] as any).encodedTraces = [];
     }
-    // See comment on our override of Traces.encode to learn more about this
-    // strategy.
+    // See comment on our override of Traces.encode inside of
+    // apollo-engine-reporting-protobuf to learn more about this strategy.
     (this.report.tracesPerQuery[statsReportKey] as any).encodedTraces.push(
       encodedTrace,
     );