Prometheus: Don't use empty matcher if there is no match parameter (#107569)

* don't use empty matcher

* nit updates

packages/grafana-prometheus/src/constants.ts

@@ -19,8 +19,9 @@ export const EMPTY_SELECTOR = '{}';
 
 export const DEFAULT_SERIES_LIMIT = 40000;
 
-export const MATCH_ALL_LABELS_STR = '__name__!=""';
-
+/**
+ * Only for /series endpoint. Don't use this anywhere else as it cause an expensive query
+ */
 export const MATCH_ALL_LABELS = '{__name__!=""}';
 
 export const METRIC_LABEL = '__name__';

packages/grafana-prometheus/src/datasource.test.ts

@@ -1016,7 +1016,7 @@ describe('PrometheusDatasource', () => {
       ];
 
       const result = extractResourceMatcher(queries, filters);
-      expect(result).toBe('{__name__!="",instance="localhost"}');
+      expect(result).toBe('{instance="localhost"}');
     });
 
     it('should extract matcher from given filters only', () => {
@@ -1035,7 +1035,7 @@ describe('PrometheusDatasource', () => {
       ];
 
       const result = extractResourceMatcher(queries, filters);
-      expect(result).toBe('{__name__!="",instance="localhost",job!="testjob"}');
+      expect(result).toBe('{instance="localhost",job!="testjob"}');
     });
 
     it('should extract matcher as match-all from no query and filter', () => {
@@ -1043,7 +1043,7 @@ describe('PrometheusDatasource', () => {
       const filters: AdHocVariableFilter[] = [];
 
       const result = extractResourceMatcher(queries, filters);
-      expect(result).toBe('{__name__!=""}');
+      expect(result).toBeUndefined();
     });
 
     it('should extract the correct matcher for queries with `... or vector(0)`', () => {

packages/grafana-prometheus/src/datasource.ts

@@ -913,7 +913,10 @@ export function extractRuleMappingFromGroups(groups: RawRecordingRules[]): RuleQ
  * adhocFilters={key:"instance", operator:"=", value:"localhost"}
  * returns {__name__=~"metricName", instance="localhost"}
  */
-export const extractResourceMatcher = (queries: PromQuery[], adhocFilters: AdHocVariableFilter[]): string => {
+export const extractResourceMatcher = (
+  queries: PromQuery[],
+  adhocFilters: AdHocVariableFilter[]
+): string | undefined => {
   // Extract metric names from queries we have already
   const metricMatch = populateMatchParamsFromQueries(queries);
   const labelFilters: QueryBuilderLabelFilter[] = adhocFilters.map((f) => ({
@@ -923,6 +926,11 @@ export const extractResourceMatcher = (queries: PromQuery[], adhocFilters: AdHoc
   }));
   // Extract label filters from the filters we have already
   const labelsMatch = renderLabelsWithoutBrackets(labelFilters);
+
+  if (metricMatch.length === 0 && labelsMatch.length === 0) {
+    return undefined;
+  }
+
   // Create a matcher using metric names and label filters
-  return `{${[metricMatch, ...labelsMatch].join(',')}}`;
+  return `{${[...metricMatch, ...labelsMatch].join(',')}}`;
 };

packages/grafana-prometheus/src/language_provider.test.ts

@@ -1042,18 +1042,18 @@ describe('PrometheusLanguageProvider with feature toggle', () => {
         { expr: 'metric2', refId: '2' },
       ];
       const result = populateMatchParamsFromQueries(queries);
-      expect(result).toBe(`__name__=~"metric1|metric2"`);
+      expect(result).toEqual([`__name__=~"metric1|metric2"`]);
     });
 
     it('should handle binary queries', () => {
       const queries: PromQuery[] = [{ expr: 'binary{label="val"} + second{}', refId: '1' }];
       const result = populateMatchParamsFromQueries(queries);
-      expect(result).toBe(`__name__=~"binary|second"`);
+      expect(result).toEqual([`__name__=~"binary|second"`]);
     });
 
     it('should handle undefined queries', () => {
       const result = populateMatchParamsFromQueries(undefined);
-      expect(result).toBe('__name__!=""');
+      expect(result).toEqual([]);
     });
 
     it('should handle UTF8 metrics', () => {
@@ -1071,13 +1071,13 @@ describe('PrometheusLanguageProvider with feature toggle', () => {
     it('should return match-all matcher if there is no expr in queries', () => {
       const queries: PromQuery[] = [{ expr: '', refId: '1' }];
       const result = populateMatchParamsFromQueries(queries);
-      expect(result).toBe('__name__!=""');
+      expect(result).toEqual([]);
     });
 
     it('should return match-all matcher if there is no query', () => {
       const queries: PromQuery[] = [];
       const result = populateMatchParamsFromQueries(queries);
-      expect(result).toBe('__name__!=""');
+      expect(result).toEqual([]);
     });
 
     it('should extract the correct matcher for queries with `... or vector(0)`', () => {
@@ -1088,7 +1088,7 @@ describe('PrometheusLanguageProvider with feature toggle', () => {
         },
       ];
       const result = populateMatchParamsFromQueries(queries);
-      expect(result).toBe('__name__=~"go_cpu_classes_idle_cpu_seconds_total"');
+      expect(result).toEqual(['__name__=~"go_cpu_classes_idle_cpu_seconds_total"']);
     });
   });
 });

packages/grafana-prometheus/src/language_provider.ts

@@ -18,7 +18,7 @@ import { BackendSrvRequest } from '@grafana/runtime';
 
 import { buildCacheHeaders, getDaysToCacheMetadata, getDefaultCacheHeaders } from './caching';
 import { Label } from './components/monaco-query-field/monaco-completion-provider/situation';
-import { DEFAULT_SERIES_LIMIT, MATCH_ALL_LABELS_STR, EMPTY_SELECTOR, REMOVE_SERIES_LIMIT } from './constants';
+import { DEFAULT_SERIES_LIMIT, EMPTY_SELECTOR, REMOVE_SERIES_LIMIT } from './constants';
 import { PrometheusDatasource } from './datasource';
 import {
   extractLabelMatchers,
@@ -796,11 +796,11 @@ function getNameLabelValue(promQuery: string, tokens: Array<string | Prism.Token
  * Handles UTF8 metrics by properly escaping them.
  *
  * @param {PromQuery[]} queries - Array of Prometheus queries
- * @returns {string} Metric names as a regex matcher
+ * @returns {string[]} Metric names as a regex matcher inside the array for easy handling
  */
-export const populateMatchParamsFromQueries = (queries?: PromQuery[]): string => {
+export const populateMatchParamsFromQueries = (queries?: PromQuery[]): string[] => {
   if (!queries) {
-    return MATCH_ALL_LABELS_STR;
+    return [];
   }
 
   const metrics = (queries ?? []).reduce<string[]>((params, query) => {
@@ -818,5 +818,5 @@ export const populateMatchParamsFromQueries = (queries?: PromQuery[]): string =>
     return params;
   }, []);
 
-  return metrics.length === 0 ? MATCH_ALL_LABELS_STR : `__name__=~"${metrics.join('|')}"`;
+  return metrics.length === 0 ? [] : [`__name__=~"${metrics.join('|')}"`];
 };

packages/grafana-prometheus/src/resource_clients.ts

@@ -73,7 +73,7 @@ export abstract class BaseResourceClient {
    * @param {string} match - Label matcher to filter time series
    * @param {string} limit - Maximum number of series to return
    */
-  public querySeries = async (timeRange: TimeRange, match: string, limit: number) => {
+  public querySeries = async (timeRange: TimeRange, match: string | undefined, limit: number) => {
     const effectiveMatch = !match || match === EMPTY_SELECTOR ? MATCH_ALL_LABELS : match;
     const timeParams = this.datasource.getTimeRangeParams(timeRange);
     const searchParams = { ...timeParams, 'match[]': effectiveMatch, limit };
@@ -97,7 +97,7 @@ export class LabelsApiClient extends BaseResourceClient implements ResourceApiCl
   public queryMetrics = async (timeRange: TimeRange): Promise<{ metrics: string[]; histogramMetrics: string[] }> => {
     this.metrics = await this.queryLabelValues(timeRange, METRIC_LABEL);
     this.histogramMetrics = processHistogramMetrics(this.metrics);
-    this._cache.setLabelValues(timeRange, MATCH_ALL_LABELS, DEFAULT_SERIES_LIMIT, this.metrics);
+    this._cache.setLabelValues(timeRange, undefined, DEFAULT_SERIES_LIMIT, this.metrics);
     return { metrics: this.metrics, histogramMetrics: this.histogramMetrics };
   };
 
@@ -177,19 +177,19 @@ export class SeriesApiClient extends BaseResourceClient implements ResourceApiCl
   };
 
   public queryMetrics = async (timeRange: TimeRange): Promise<{ metrics: string[]; histogramMetrics: string[] }> => {
-    const series = await this.querySeries(timeRange, MATCH_ALL_LABELS, DEFAULT_SERIES_LIMIT);
+    const series = await this.querySeries(timeRange, undefined, DEFAULT_SERIES_LIMIT);
     const { metrics, labelKeys } = processSeries(series, METRIC_LABEL);
     this.metrics = metrics;
     this.histogramMetrics = processHistogramMetrics(this.metrics);
     this.labelKeys = labelKeys;
-    this._cache.setLabelValues(timeRange, MATCH_ALL_LABELS, DEFAULT_SERIES_LIMIT, metrics);
-    this._cache.setLabelKeys(timeRange, MATCH_ALL_LABELS, DEFAULT_SERIES_LIMIT, labelKeys);
+    this._cache.setLabelValues(timeRange, undefined, DEFAULT_SERIES_LIMIT, metrics);
+    this._cache.setLabelKeys(timeRange, undefined, DEFAULT_SERIES_LIMIT, labelKeys);
     return { metrics: this.metrics, histogramMetrics: this.histogramMetrics };
   };
 
   public queryLabelKeys = async (timeRange: TimeRange, match?: string, limit?: number): Promise<string[]> => {
     const effectiveLimit = this.getEffectiveLimit(limit);
-    const effectiveMatch = !match || match === EMPTY_SELECTOR ? MATCH_ALL_LABELS : match;
+    const effectiveMatch = !match || match === EMPTY_SELECTOR ? undefined : match;
     const maybeCachedKeys = this._cache.getLabelKeys(timeRange, effectiveMatch, effectiveLimit);
     if (maybeCachedKeys) {
       return maybeCachedKeys;
@@ -247,7 +247,7 @@ class ResourceClientsCache {
 
   constructor(private cacheLevel: PrometheusCacheLevel = PrometheusCacheLevel.High) {}
 
-  public setLabelKeys(timeRange: TimeRange, match: string, limit: number, keys: string[]) {
+  public setLabelKeys(timeRange: TimeRange, match: string | undefined, limit: number, keys: string[]) {
     if (keys.length === 0) {
       return;
     }
@@ -258,7 +258,7 @@ class ResourceClientsCache {
     this._accessTimestamps[cacheKey] = Date.now();
   }
 
-  public getLabelKeys(timeRange: TimeRange, match: string, limit: number): string[] | undefined {
+  public getLabelKeys(timeRange: TimeRange, match: string | undefined, limit: number): string[] | undefined {
     const cacheKey = this.getCacheKey(timeRange, match, limit, 'key');
     const result = this._cache[cacheKey];
     if (result) {
@@ -268,7 +268,7 @@ class ResourceClientsCache {
     return result;
   }
 
-  public setLabelValues(timeRange: TimeRange, match: string, limit: number, values: string[]) {
+  public setLabelValues(timeRange: TimeRange, match: string | undefined, limit: number, values: string[]) {
     if (values.length === 0) {
       return;
     }
@@ -289,7 +289,7 @@ class ResourceClientsCache {
     return result;
   }
 
-  private getCacheKey(timeRange: TimeRange, match: string, limit: number, type: 'key' | 'value') {
+  private getCacheKey(timeRange: TimeRange, match: string | undefined, limit: number, type: 'key' | 'value') {
     const snappedTimeRange = getRangeSnapInterval(this.cacheLevel, timeRange);
     return [snappedTimeRange.start, snappedTimeRange.end, limit, match, type].join('|');
   }