Turn filter editor suggestions back on by default

docs/discover/field-filter.asciidoc

@@ -70,9 +70,10 @@ displayed below the query bar instead of the filter definition.
 . Click *Save*. The filter will be applied to your search and be displayed below
 the query bar.
 
-NOTE: To make the filter editor more user-friendly, you can enable the `filterEditor:suggestValues` advanced setting.
-Enabling this will cause the editor to suggest values from your indices if you are filtering against an aggregatable
-field. However, this is not recommended for extremely large datasets, as it can result in long queries.
+NOTE: By default, the filter editor will suggest values for fields that are aggregatable. If this
+results in long-running requests, you can configure the `filterEditor:suggestions:terminateAfter`
+advanced setting. Setting it to a lower value will result in quicker requests but may also result
+in less helpful suggestions. Setting it to `0` will disable suggestions completely.
 
 [float]
 [[filter-pinning]]

docs/management/advanced-options.asciidoc

@@ -74,7 +74,7 @@ mentioned use "_default_".
 `timepicker:refreshIntervalDefaults`:: The time filter's default refresh interval.
 `dashboard:defaultDarkTheme`:: Set this property to `true` to make new dashboards use the dark theme by default.
 `filters:pinnedByDefault`:: Set this property to `true` to make filters have a global state by default.
-`filterEditor:suggestValues`:: Set this property to `true` to have the filter editor suggest values for fields, instead of just providing a text input. This may result in heavy queries to Elasticsearch.
+`filterEditor:suggestions:terminateAfter`:: By default, the filter editor will suggest values for aggregatable fields. Setting this to a lower value will make the request for aggregatable fields quicker, yet may result in fewer suggestions. Set to `0` to disable suggestions entirely.
 `notifications:banner`:: You can specify a custom banner to display temporary notices to all users. This field supports
 Markdown.
 `notifications:lifetime:banner`:: Specifies the duration in milliseconds for banner notification displays. The default value is 3000000. Set this field to `Infinity` to disable banner notifications.

src/core_plugins/kibana/server/routes/api/suggestions/register_value_suggestions.js

@@ -4,33 +4,39 @@ export function registerValueSuggestions(server) {
   server.route({
     path: '/api/kibana/suggestions/values/{index}',
     method: ['POST'],
-    handler: function (req, reply) {
+    handler: async function (req, reply) {
+      const uiSettings = req.getUiSettingsService();
       const { index } = req.params;
       const { field, query } = req.payload;
+      const terminateAfter = await uiSettings.get('filterEditor:suggestions:terminateAfter');
 
       const { callWithRequest } = server.plugins.elasticsearch.getCluster('data');
-      const include = query ? `.*${query}.*` : undefined;
-      const body = getBody({
-        field,
-        include,
-        shard_size: 10,
-        size: 10
-      });
+      const body = getBody({ field, query, terminateAfter });
 
-      return callWithRequest(req, 'search', { index, body })
-      .then((res) => {
-        const suggestions = res.aggregations.suggestions.buckets.map(bucket => bucket.key);
+      try {
+        const response = await callWithRequest(req, 'search', { index, body });
+        const suggestions = response.aggregations.suggestions.buckets.map(bucket => bucket.key);
         return reply(suggestions);
-      })
-      .catch(error => reply(handleESError(error)));
+      } catch (error) {
+        return reply(handleESError(error));
+      }
     }
   });
 }
 
-function getBody(terms) {
+function getBody({ field, query, terminateAfter }) {
+  const include = query ? `.*${query}.*` : undefined;
   return {
+    size: 0,
+    terminate_after: terminateAfter,
     aggs: {
-      suggestions: { terms }
+      suggestions: {
+        terms: {
+          field,
+          include,
+          execution_hint: 'map'
+        }
+      }
     }
   };
 }

src/core_plugins/kibana/ui_setting_defaults.js

@@ -264,10 +264,10 @@ export function getUiSettingDefaults() {
       value: false,
       description: 'Whether the filters should have a global state (be pinned) by default'
     },
-    'filterEditor:suggestValues': {
-      value: false,
-      description: 'Set this property to `true` to have the filter editor suggest values for fields, ' +
-        'instead of just providing a text input. This may result in heavy queries to Elasticsearch.'
+    'filterEditor:suggestions:terminateAfter': {
+      value: 10000,
+      description: 'By default, the filter editor will suggest values for aggregatable fields. Setting this to a lower value will make the'
+        + 'request for aggregatable fields quicker, yet may result in fewer suggestions. Set to `0` to disable suggestions entirely.'
     },
     'notifications:banner': {
       type: 'markdown',

src/ui/public/filter_editor/params_editor/filter_params_phrase_controller.js

@@ -4,12 +4,9 @@ import chrome from 'ui/chrome';
 const baseUrl = chrome.addBasePath('/api/kibana/suggestions/values');
 
 export function filterParamsPhraseController($http, $scope, config) {
-  const shouldSuggestValues = this.shouldSuggestValues = config.get('filterEditor:suggestValues');
-
+  const shouldSuggestValues = this.shouldSuggestValues = (config.get('filterEditor:suggestions:terminateAfter') !== 0);
   this.compactUnion = _.flow(_.union, _.compact);
-
   this.getValueSuggestions = _.memoize(getValueSuggestions, getFieldQueryHash);
-
   this.refreshValueSuggestions = (query) => {
     return this.getValueSuggestions($scope.field, query)
       .then(suggestions => $scope.valueSuggestions = suggestions);
@@ -32,7 +29,7 @@ export function filterParamsPhraseController($http, $scope, config) {
       .catch(() => []);
   }
 
-  function getFieldQueryHash(field, query) {
+  function getFieldQueryHash(field, query = '') {
     return `${field.indexPattern.id}/${field.name}/${query}`;
   }
 }