fix: GraphQL schema rebuilds leak Apollo signal handlers and pin old schema graphs in memory

spec/ParseGraphQLServer.spec.js

@@ -135,6 +135,29 @@ describe('ParseGraphQLServer', () => {
         expect(server).toBe(firstServer);
       });
     });
+
+    it('does not leak process signal listeners across schema rebuilds (#9813)', async () => {
+      const originalNodeEnv = process.env.NODE_ENV;
+      // Apollo registers SIGINT/SIGTERM handlers only when NODE_ENV !== 'test'; force the
+      // production path so the (pre-fix) leak is exercised deterministically.
+      process.env.NODE_ENV = 'production';
+      try {
+        parseGraphQLServer.server = undefined;
+        await parseGraphQLServer._getServer();
+        const before = process.listenerCount('SIGTERM') + process.listenerCount('SIGINT');
+        // Force several real schema rebuilds (each new class changes the schema).
+        for (let i = 0; i < 5; i++) {
+          await new Parse.Object(`LeakClass${i}`).save();
+          await parseGraphQLServer._getServer();
+        }
+        const after = process.listenerCount('SIGTERM') + process.listenerCount('SIGINT');
+        // Fix: discarded ApolloServers register no process listeners, so the count is stable.
+        // Baseline: each rebuild leaks a SIGINT + SIGTERM listener (grows by 2 per rebuild).
+        expect(after).toBe(before);
+      } finally {
+        process.env.NODE_ENV = originalNodeEnv;
+      }
+    });
   });
 
   describe('_getGraphQLOptions', () => {

src/GraphQL/ParseGraphQLServer.js

@@ -180,6 +180,13 @@ class ParseGraphQLServer {
           // We need always true introspection because apollo server have changing behavior based on the NODE_ENV variable
           // we delegate the introspection control to the IntrospectionControlPlugin
           introspection: true,
+          // A new ApolloServer is created every time the GraphQL schema changes, and Parse Server
+          // already manages its own SIGTERM/SIGINT graceful shutdown (see configureListeners in
+          // ParseServer). Left to its default, apollo.start() registers a SIGINT and a SIGTERM
+          // listener on the global `process` per build and only removes them on apollo.stop() —
+          // which is never called on the discarded server — pinning every old ApolloServer and its
+          // entire GraphQL schema graph in memory forever. (#9813)
+          stopOnTerminationSignals: false,
           plugins: [ApolloServerPluginCacheControlDisabled(), IntrospectionControlPlugin(this.config.graphQLPublicIntrospection), SchemaSuggestionsControlPlugin(this.config.graphQLPublicIntrospection), createComplexityValidationPlugin(() => this.parseServer.config.requestComplexity)],
           schema,
         });