[Watcher] Prevent expensive queries on ES by using PointInTimeFinder to get indexPatterns (#119717)

* Use PointInTimeFinder to paginate through indexPatterns in a more performant way

* commit using @elastic.co

* Start working on tests

* Add tests

* Add missing types

* Fix tests

* Update tests responses

* Remove unnecessary mocks

* Fix type

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/watcher/__jest__/client_integration/watch_create_threshold.test.tsx

@@ -50,14 +50,6 @@ jest.mock('../../public/application/lib/api', () => {
 
   return {
     ...original,
-    loadIndexPatterns: async () => {
-      const INDEX_PATTERNS = [
-        { attributes: { title: 'index1' } },
-        { attributes: { title: 'index2' } },
-        { attributes: { title: 'index3' } },
-      ];
-      return await INDEX_PATTERNS;
-    },
     getHttpClient: () => mockHttpClient,
   };
 });

x-pack/plugins/watcher/__jest__/client_integration/watch_edit.test.ts

@@ -23,14 +23,6 @@ jest.mock('../../public/application/lib/api', () => {
 
   return {
     ...original,
-    loadIndexPatterns: async () => {
-      const INDEX_PATTERNS = [
-        { attributes: { title: 'index1' } },
-        { attributes: { title: 'index2' } },
-        { attributes: { title: 'index3' } },
-      ];
-      return await INDEX_PATTERNS;
-    },
     getHttpClient: () => mockHttpClient,
   };
 });

x-pack/plugins/watcher/public/application/lib/api.ts

@@ -151,12 +151,10 @@ export const executeWatch = async (executeWatchDetails: ExecutedWatchDetails, wa
 };
 
 export const loadIndexPatterns = async () => {
-  const { savedObjects } = await getSavedObjectsClient().find({
-    type: 'index-pattern',
-    fields: ['title'],
-    perPage: 10000,
+  return sendRequest({
+    path: `${basePath}/indices/index_patterns`,
+    method: 'get',
   });
-  return savedObjects;
 };
 
 const getWatchVisualizationDataDeserializer = (data: { visualizeData: any }) => data?.visualizeData;

x-pack/plugins/watcher/public/application/sections/watch_edit/components/threshold_watch_edit/threshold_watch_edit.tsx

@@ -182,9 +182,8 @@ export const ThresholdWatchEdit = ({ pageTitle }: { pageTitle: string }) => {
 
   useEffect(() => {
     const getIndexPatterns = async () => {
-      const indexPatternObjects = await loadIndexPatterns();
-      const titles = indexPatternObjects.map((indexPattern: any) => indexPattern.attributes.title);
-      setIndexPatterns(titles);
+      const { data: indexPatternTitles } = await loadIndexPatterns();
+      setIndexPatterns(indexPatternTitles);
     };
 
     const loadData = async () => {

x-pack/plugins/watcher/server/routes/api/indices/register_get_index_patterns_route.ts

@@ -0,0 +1,47 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { SavedObjectsFindResult } from 'src/core/server';
+import { RouteDependencies } from '../../../types';
+
+export function registerGetIndexPatternsRoute({
+  router,
+  license,
+  lib: { handleEsError },
+}: RouteDependencies) {
+  router.get(
+    {
+      path: '/api/watcher/indices/index_patterns',
+      validate: false,
+    },
+    license.guardApiRoute(async ({ core: { savedObjects } }, request, response) => {
+      try {
+        const finder = savedObjects.client.createPointInTimeFinder({
+          type: 'index-pattern',
+          fields: ['title'],
+          perPage: 1000,
+        });
+
+        const responses: string[] = [];
+
+        for await (const result of finder.find()) {
+          responses.push(
+            ...result.saved_objects.map(
+              (indexPattern: SavedObjectsFindResult<any>) => indexPattern.attributes.title
+            )
+          );
+        }
+
+        await finder.close();
+
+        return response.ok({ body: responses });
+      } catch (error) {
+        return handleEsError({ error, response });
+      }
+    })
+  );
+}

x-pack/plugins/watcher/server/routes/api/indices/register_indices_routes.ts

@@ -6,8 +6,10 @@
  */
 
 import { registerGetRoute } from './register_get_route';
+import { registerGetIndexPatternsRoute } from './register_get_index_patterns_route';
 import { RouteDependencies } from '../../../types';
 
 export function registerIndicesRoutes(deps: RouteDependencies) {
   registerGetRoute(deps);
+  registerGetIndexPatternsRoute(deps);
 }

x-pack/test/api_integration/apis/index.ts

@@ -34,5 +34,6 @@ export default function ({ loadTestFile }: FtrProviderContext) {
     loadTestFile(require.resolve('./painless_lab'));
     loadTestFile(require.resolve('./file_upload'));
     loadTestFile(require.resolve('./ml'));
+    loadTestFile(require.resolve('./watcher'));
   });
 }

x-pack/test/api_integration/apis/watcher/index.ts

@@ -0,0 +1,14 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { FtrProviderContext } from '../../ftr_provider_context';
+
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('Watcher', () => {
+    loadTestFile(require.resolve('./watcher'));
+  });
+}

x-pack/test/api_integration/apis/watcher/watcher.ts

@@ -0,0 +1,47 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import expect from '@kbn/expect';
+
+import { FtrProviderContext } from '../../ftr_provider_context';
+
+export default function ({ getService }: FtrProviderContext) {
+  const log = getService('log');
+  const supertest = getService('supertest');
+  const transform = getService('transform');
+
+  describe('watcher', () => {
+    before(async () => {
+      try {
+        await transform.testResources.createIndexPatternIfNeeded('ft_ecommerce', 'order_date');
+      } catch (error) {
+        log.debug('[Setup error] Error creating index pattern');
+        throw error;
+      }
+    });
+
+    after(async () => {
+      try {
+        await transform.testResources.deleteIndexPatternByTitle('ft_ecommerce');
+      } catch (error) {
+        log.debug('[Cleanup error] Error deleting index pattern');
+        throw error;
+      }
+    });
+
+    describe('POST /api/watcher/indices/index_patterns', () => {
+      it('returns list of index patterns', async () => {
+        const response = await supertest
+          .get('/api/watcher/indices/index_patterns')
+          .set('kbn-xsrf', 'kibana')
+          .expect(200);
+
+        expect(response.body).to.contain('ft_ecommerce');
+      });
+    });
+  });
+}