[APM] Add kibana config for limiting the number of services in a service group

x-pack/plugins/apm/server/routes/service_groups/lookup_services.ts

@@ -14,18 +14,19 @@ import {
 } from '../../../common/elasticsearch_fieldnames';
 import { ProcessorEvent } from '../../../common/processor_event';
 import { Setup } from '../../lib/helpers/setup_request';
-import { MAX_NUMBER_OF_SERVICE_GROUPS } from '../../../common/service_groups';
 
 export async function lookupServices({
   setup,
   kuery,
   start,
   end,
+  maxNumberOfServices,
 }: {
   setup: Setup;
   kuery: string;
   start: number;
   end: number;
+  maxNumberOfServices: number;
 }) {
   const { apmEventClient } = setup;
 
@@ -49,7 +50,7 @@ export async function lookupServices({
         services: {
           terms: {
             field: SERVICE_NAME,
-            size: MAX_NUMBER_OF_SERVICE_GROUPS,
+            size: maxNumberOfServices,
           },
           aggs: {
             environments: {

x-pack/plugins/apm/server/routes/service_groups/route.ts

@@ -6,6 +6,7 @@
  */
 
 import * as t from 'io-ts';
+import { apmServiceGroupMaxNumberOfServices } from '@kbn/observability-plugin/common';
 import { setupRequest } from '../../lib/helpers/setup_request';
 import { createApmServerRoute } from '../apm_routes/create_apm_server_route';
 import { kueryRt, rangeRt } from '../default_api_types';
@@ -28,8 +29,12 @@ const serviceGroupsRoute = createApmServerRoute({
     resources
   ): Promise<{ serviceGroups: SavedServiceGroup[] }> => {
     const { context } = resources;
-    const savedObjectsClient = (await context.core).savedObjects.client;
-    const serviceGroups = await getServiceGroups({ savedObjectsClient });
+    const {
+      savedObjects: { client: savedObjectsClient },
+    } = await context.core;
+    const serviceGroups = await getServiceGroups({
+      savedObjectsClient,
+    });
     return { serviceGroups };
   },
 });
@@ -46,7 +51,9 @@ const serviceGroupRoute = createApmServerRoute({
   },
   handler: async (resources): Promise<{ serviceGroup: SavedServiceGroup }> => {
     const { context, params } = resources;
-    const savedObjectsClient = (await context.core).savedObjects.client;
+    const {
+      savedObjects: { client: savedObjectsClient },
+    } = await context.core;
     const serviceGroup = await getServiceGroup({
       savedObjectsClient,
       serviceGroupId: params.query.serviceGroup,
@@ -75,13 +82,21 @@ const serviceGroupSaveRoute = createApmServerRoute({
   handler: async (resources): Promise<void> => {
     const { context, params } = resources;
     const { start, end, serviceGroupId } = params.query;
-    const savedObjectsClient = (await context.core).savedObjects.client;
-    const setup = await setupRequest(resources);
+    const {
+      savedObjects: { client: savedObjectsClient },
+      uiSettings: { client: uiSettingsClient },
+    } = await context.core;
+    const [setup, maxNumberOfServices] = await Promise.all([
+      setupRequest(resources),
+      uiSettingsClient.get<number>(apmServiceGroupMaxNumberOfServices),
+    ]);
+
     const items = await lookupServices({
       setup,
       kuery: params.body.kuery,
       start,
       end,
+      maxNumberOfServices,
     });
     const serviceNames = items.map(({ serviceName }): string => serviceName);
     const serviceGroup: ServiceGroup = {
@@ -126,14 +141,21 @@ const serviceGroupServicesRoute = createApmServerRoute({
   handler: async (
     resources
   ): Promise<{ items: Awaited<ReturnType<typeof lookupServices>> }> => {
-    const { params } = resources;
+    const { params, context } = resources;
     const { kuery = '', start, end } = params.query;
-    const setup = await setupRequest(resources);
+    const {
+      uiSettings: { client: uiSettingsClient },
+    } = await context.core;
+    const [setup, maxNumberOfServices] = await Promise.all([
+      setupRequest(resources),
+      uiSettingsClient.get<number>(apmServiceGroupMaxNumberOfServices),
+    ]);
     const items = await lookupServices({
       setup,
       kuery,
       start,
       end,
+      maxNumberOfServices,
     });
     return { items };
   },

x-pack/plugins/observability/common/index.ts

@@ -17,6 +17,7 @@ export {
   defaultApmServiceEnvironment,
   apmServiceInventoryOptimizedSorting,
   apmProgressiveLoading,
+  apmServiceGroupMaxNumberOfServices,
 } from './ui_settings_keys';
 
 export {

x-pack/plugins/observability/common/ui_settings_keys.ts

@@ -15,3 +15,5 @@ export const apmProgressiveLoading = 'observability:apmProgressiveLoading';
 export const enableServiceGroups = 'observability:enableServiceGroups';
 export const apmServiceInventoryOptimizedSorting =
   'observability:apmServiceInventoryOptimizedSorting';
+export const apmServiceGroupMaxNumberOfServices =
+  'observability:apmServiceGroupMaxNumberOfServices';

x-pack/plugins/observability/public/index.ts

@@ -29,6 +29,7 @@ export {
   enableInfrastructureView,
   enableServiceGroups,
   enableNewSyntheticsView,
+  apmServiceGroupMaxNumberOfServices,
 } from '../common/ui_settings_keys';
 export { uptimeOverviewLocatorID } from '../common';
 

x-pack/plugins/observability/server/ui_settings.ts

@@ -19,6 +19,7 @@ import {
   enableServiceGroups,
   apmServiceInventoryOptimizedSorting,
   enableNewSyntheticsView,
+  apmServiceGroupMaxNumberOfServices,
 } from '../common/ui_settings_keys';
 
 const technicalPreviewLabel = i18n.translate(
@@ -187,4 +188,15 @@ export const uiSettings: Record<string, UiSettingsParams<boolean | number | stri
     requiresPageReload: false,
     type: 'boolean',
   },
+  [apmServiceGroupMaxNumberOfServices]: {
+    category: [observabilityFeatureId],
+    name: i18n.translate('xpack.observability.serviceGroupMaxServicesUiSettingName', {
+      defaultMessage: 'Maximum services in a service group',
+    }),
+    value: 500,
+    description: i18n.translate('xpack.observability.serviceGroupMaxServicesUiSettingDescription', {
+      defaultMessage: 'Limit the number of services in a given service group',
+    }),
+    schema: schema.number({ min: 1 }),
+  },
 };