address @eli comments

src/core/server/http/http_server.ts

@@ -155,7 +155,7 @@ export class HttpServer {
     await this.server.start();
     const serverPath = this.config!.rewriteBasePath || this.config!.basePath || '';
     this.log.info('http server running');
-    this.log.debug(`http server listens at ${this.server.info.uri}${serverPath}`);
+    this.log.debug(`http server listening on ${this.server.info.uri}${serverPath}`);
   }
 
   public async stop() {

src/core/server/http/http_service.test.ts

@@ -214,6 +214,30 @@ test('stops http server', async () => {
   expect(httpServer.stop).toHaveBeenCalledTimes(1);
 });
 
+test('stops not ready server if it is running', async () => {
+  const configService = createConfigService();
+  const mockHapiServer = {
+    start: jest.fn(),
+    stop: jest.fn(),
+    route: jest.fn(),
+  };
+  const httpServer = {
+    isListening: () => false,
+    setup: jest.fn().mockReturnValue({ server: mockHapiServer }),
+    start: noop,
+    stop: jest.fn(),
+  };
+  mockHttpServer.mockImplementation(() => httpServer);
+
+  const service = new HttpService({ configService, env, logger });
+
+  await service.setup();
+
+  await service.stop();
+
+  expect(mockHapiServer.stop).toHaveBeenCalledTimes(1);
+});
+
 test('register route handler', async () => {
   const configService = createConfigService();
 

src/core/server/http/http_service.ts

@@ -94,7 +94,9 @@ export class HttpService implements CoreService<HttpServiceSetup, HttpServiceSta
     const config = await this.config$.pipe(first()).toPromise();
     if (this.shouldListen(config)) {
       if (this.notReadyServer) {
+        this.log.debug('stopping NotReady server');
         await this.notReadyServer.stop();
+        this.notReadyServer = undefined;
       }
       // If a redirect port is specified, we start an HTTP server at this port and
       // redirect all requests to the SSL port.
@@ -162,13 +164,17 @@ export class HttpService implements CoreService<HttpServiceSetup, HttpServiceSta
     this.configSubscription.unsubscribe();
     this.configSubscription = undefined;
 
+    if (this.notReadyServer) {
+      await this.notReadyServer.stop();
+    }
     await this.httpServer.stop();
     await this.httpsRedirectServer.stop();
     await Promise.all([...this.secondaryServers.values()].map(s => s.stop()));
     this.secondaryServers.clear();
   }
 
   private async runNotReadyServer(config: HttpConfig) {
+    this.log.debug('starting NotReady server');
     const httpServer = new HttpServer(this.log);
     const { server } = await httpServer.setup(config);
     this.notReadyServer = server;