[User experience] Fix JS error rate

x-pack/plugins/apm/server/lib/rum_client/get_client_metrics.ts

@@ -4,7 +4,6 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { TRANSACTION_DURATION } from '../../../common/elasticsearch_fieldnames';
 import { getRumPageLoadTransactionsProjection } from '../../projections/rum_page_load_transactions';
 import { mergeProjection } from '../../projections/util/merge_projection';
 import { Setup, SetupTimeRange } from '../helpers/setup_request';
@@ -25,17 +24,14 @@ export async function getClientMetrics({
   const projection = getRumPageLoadTransactionsProjection({
     setup,
     urlQuery,
+    checkFetchStartFieldExists: false,
   });
 
   const params = mergeProjection(projection, {
     body: {
       size: 0,
+      track_total_hits: true,
       aggs: {
-        pageViews: {
-          value_count: {
-            field: TRANSACTION_DURATION,
-          },
-        },
         backEnd: {
           percentiles: {
             field: TRANSACTION_TIME_TO_FIRST_BYTE,
@@ -59,15 +55,14 @@ export async function getClientMetrics({
   });
 
   const { apmEventClient } = setup;
-
   const response = await apmEventClient.search(params);
-  const { backEnd, domInteractive, pageViews } = response.aggregations!;
+  const { backEnd, domInteractive } = response.aggregations!;
 
   const pkey = percentile.toFixed(1);
 
   // Divide by 1000 to convert ms into seconds
   return {
-    pageViews,
+    pageViews: { value: response.hits.total.value ?? 0 },
     backEnd: { value: backEnd.values[pkey] || 0 },
     frontEnd: {
       value: (domInteractive.values[pkey] || 0) - (backEnd.values[pkey] || 0),

x-pack/plugins/apm/server/projections/rum_page_load_transactions.ts

@@ -17,23 +17,29 @@ import { TRANSACTION_PAGE_LOAD } from '../../common/transaction_types';
 export function getRumPageLoadTransactionsProjection({
   setup,
   urlQuery,
+  checkFetchStartFieldExists = true,
 }: {
   setup: Setup & SetupTimeRange;
   urlQuery?: string;
+  checkFetchStartFieldExists?: boolean;
 }) {
   const { start, end, esFilter } = setup;
 
   const bool = {
     filter: [
       { range: rangeFilter(start, end) },
       { term: { [TRANSACTION_TYPE]: TRANSACTION_PAGE_LOAD } },
-      {
-        // Adding this filter to cater for some inconsistent rum data
-        // not available on aggregated transactions
-        exists: {
-          field: 'transaction.marks.navigationTiming.fetchStart',
-        },
-      },
+      ...(checkFetchStartFieldExists
+        ? [
+            {
+              // Adding this filter to cater for some inconsistent rum data
+              // not available on aggregated transactions
+              exists: {
+                field: 'transaction.marks.navigationTiming.fetchStart',
+              },
+            },
+          ]
+        : []),
       ...(urlQuery
         ? [
             {