[ML] APM Latency Correlations: Code consolidation. (elastic#110790)

Code deduplication:
- combine 3 existing client side hooks into useSearchStrategy
- combine server side multiple search strategy files into shared search_strategy_provider.ts
- Clarified naming (client/server params, strategy naming etc.), improved types.
- None of the actual deeper internal logic changed, larger chunks of code that show up as new lines is mostly just moved code + additional types (e.g. function overloads) to support the different search strategies with the same server side code and client side hook.

x-pack/plugins/apm/common/search_strategies/constants.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.
+ */
+
+export const APM_SEARCH_STRATEGIES = {
+  APM_FAILED_TRANSACTIONS_CORRELATIONS: 'apmFailedTransactionsCorrelations',
+  APM_LATENCY_CORRELATIONS: 'apmLatencyCorrelations',
+} as const;
+export type ApmSearchStrategies = typeof APM_SEARCH_STRATEGIES[keyof typeof APM_SEARCH_STRATEGIES];
+
+export const DEFAULT_PERCENTILE_THRESHOLD = 95;

x-pack/plugins/apm/common/search_strategies/failure_correlations/constants.ts → x-pack/plugins/apm/common/search_strategies/failed_transactions_correlations/constants.ts

@@ -7,9 +7,6 @@
 
 import { i18n } from '@kbn/i18n';
 
-export const FAILED_TRANSACTIONS_CORRELATION_SEARCH_STRATEGY =
-  'apmFailedTransactionsCorrelationsSearchStrategy';
-
 export const FAILED_TRANSACTIONS_IMPACT_THRESHOLD = {
   HIGH: i18n.translate(
     'xpack.apm.correlations.failedTransactions.highImpactText',

x-pack/plugins/apm/common/search_strategies/failed_transactions_correlations/types.ts

@@ -0,0 +1,34 @@
+/*
+ * 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 {
+  FieldValuePair,
+  RawResponseBase,
+  SearchStrategyClientParams,
+} from '../types';
+
+import { FAILED_TRANSACTIONS_IMPACT_THRESHOLD } from './constants';
+
+export interface FailedTransactionsCorrelation extends FieldValuePair {
+  doc_count: number;
+  bg_count: number;
+  score: number;
+  pValue: number | null;
+  normalizedScore: number;
+  failurePercentage: number;
+  successPercentage: number;
+}
+
+export type FailedTransactionsCorrelationsImpactThreshold = typeof FAILED_TRANSACTIONS_IMPACT_THRESHOLD[keyof typeof FAILED_TRANSACTIONS_IMPACT_THRESHOLD];
+
+export type FailedTransactionsCorrelationsParams = SearchStrategyClientParams;
+
+export interface FailedTransactionsCorrelationsRawResponse
+  extends RawResponseBase {
+  log: string[];
+  failedTransactionsCorrelations: FailedTransactionsCorrelation[];
+}

x-pack/plugins/apm/common/search_strategies/latency_correlations/types.ts

@@ -0,0 +1,40 @@
+/*
+ * 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 {
+  FieldValuePair,
+  HistogramItem,
+  RawResponseBase,
+  SearchStrategyClientParams,
+} from '../types';
+
+export interface LatencyCorrelation extends FieldValuePair {
+  correlation: number;
+  histogram: HistogramItem[];
+  ksTest: number;
+}
+
+export interface LatencyCorrelationSearchServiceProgress {
+  started: number;
+  loadedHistogramStepsize: number;
+  loadedOverallHistogram: number;
+  loadedFieldCandidates: number;
+  loadedFieldValuePairs: number;
+  loadedHistograms: number;
+}
+
+export interface LatencyCorrelationsParams extends SearchStrategyClientParams {
+  percentileThreshold: number;
+  analyzeCorrelations: boolean;
+}
+
+export interface LatencyCorrelationsRawResponse extends RawResponseBase {
+  log: string[];
+  overallHistogram?: HistogramItem[];
+  percentileThresholdValue?: number;
+  latencyCorrelations?: LatencyCorrelation[];
+}

x-pack/plugins/apm/common/search_strategies/types.ts

@@ -0,0 +1,50 @@
+/*
+ * 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.
+ */
+
+export interface FieldValuePair {
+  fieldName: string;
+  // For dynamic fieldValues we only identify fields as `string`,
+  // but for example `http.response.status_code` which is part of
+  // of the list of predefined field candidates is of type long/number.
+  fieldValue: string | number;
+}
+
+export interface HistogramItem {
+  key: number;
+  doc_count: number;
+}
+
+export interface ResponseHitSource {
+  [s: string]: unknown;
+}
+
+export interface ResponseHit {
+  _source: ResponseHitSource;
+}
+
+export interface RawResponseBase {
+  ccsWarning: boolean;
+  took: number;
+}
+
+export interface SearchStrategyClientParams {
+  environment: string;
+  kuery: string;
+  serviceName?: string;
+  transactionName?: string;
+  transactionType?: string;
+  start?: string;
+  end?: string;
+}
+
+export interface SearchStrategyServerParams {
+  index: string;
+  includeFrozen?: boolean;
+}
+
+export type SearchStrategyParams = SearchStrategyClientParams &
+  SearchStrategyServerParams;

x-pack/plugins/apm/public/components/app/correlations/correlations_table.tsx

@@ -14,36 +14,31 @@ import type { Criteria } from '@elastic/eui/src/components/basic_table/basic_tab
 import { FETCH_STATUS } from '../../../hooks/use_fetcher';
 import { useUiTracker } from '../../../../../observability/public';
 import { useTheme } from '../../../hooks/use_theme';
-import type { CorrelationsTerm } from '../../../../common/search_strategies/failure_correlations/types';
+import type { FieldValuePair } from '../../../../common/search_strategies/types';
 
 const PAGINATION_SIZE_OPTIONS = [5, 10, 20, 50];
 
-export type SelectedCorrelationTerm<T extends CorrelationsTerm> = Pick<
-  T,
-  'fieldName' | 'fieldValue'
->;
-
-interface Props<T> {
+interface CorrelationsTableProps<T extends FieldValuePair> {
   significantTerms?: T[];
   status: FETCH_STATUS;
   percentageColumnName?: string;
   setSelectedSignificantTerm: (term: T | null) => void;
-  selectedTerm?: { fieldName: string; fieldValue: string };
+  selectedTerm?: FieldValuePair;
   onFilter?: () => void;
   columns: Array<EuiBasicTableColumn<T>>;
   onTableChange: (c: Criteria<T>) => void;
   sorting?: EuiTableSortingType<T>;
 }
 
-export function CorrelationsTable<T extends CorrelationsTerm>({
+export function CorrelationsTable<T extends FieldValuePair>({
   significantTerms,
   status,
   setSelectedSignificantTerm,
   columns,
   selectedTerm,
   onTableChange,
   sorting,
-}: Props<T>) {
+}: CorrelationsTableProps<T>) {
   const euiTheme = useTheme();
   const trackApmEvent = useUiTracker({ app: 'apm' });
   const trackSelectSignificantCorrelationTerm = useCallback(