Merge pull request #13774 from miqh/feat/sum-query-suggestion

Implement sum aggregation suggestion with placeholder support

public/app/plugins/datasource/prometheus/datasource.ts

@@ -464,6 +464,9 @@ export class PrometheusDatasource {
       case 'ADD_RATE': {
         return `rate(${query}[5m])`;
       }
+      case 'ADD_SUM': {
+        return `sum(${query.trim()}) by ($1)`;
+      }
       case 'EXPAND_RULES': {
         const mapping = action.mapping;
         if (mapping) {

public/app/plugins/datasource/prometheus/query_hints.ts

@@ -2,6 +2,11 @@ import _ from 'lodash';
 
 import { QueryHint } from 'app/types/explore';
 
+/**
+ * Number of time series results needed before starting to suggest sum aggregation hints
+ */
+export const SUM_HINT_THRESHOLD_COUNT = 20;
+
 export function getQueryHints(query: string, series?: any[], datasource?: any): QueryHint[] {
   const hints = [];
 
@@ -90,5 +95,24 @@ export function getQueryHints(query: string, series?: any[], datasource?: any):
       });
     }
   }
+
+  if (series.length >= SUM_HINT_THRESHOLD_COUNT) {
+    const simpleMetric = query.trim().match(/^\w+$/);
+    if (simpleMetric) {
+      hints.push({
+        type: 'ADD_SUM',
+        label: 'Many time series results returned.',
+        fix: {
+          label: 'Consider aggregating with sum().',
+          action: {
+            type: 'ADD_SUM',
+            query: query,
+            preventSubmit: true,
+          },
+        },
+      });
+    }
+  }
+
   return hints.length > 0 ? hints : null;
 }

public/app/plugins/datasource/prometheus/specs/query_hints.test.ts

@@ -1,4 +1,4 @@
-import { getQueryHints } from '../query_hints';
+import { getQueryHints, SUM_HINT_THRESHOLD_COUNT } from '../query_hints';
 
 describe('getQueryHints()', () => {
   it('returns no hints for no series', () => {
@@ -79,4 +79,23 @@ describe('getQueryHints()', () => {
       },
     });
   });
+
+  it('returns a sum hint when many time series results are returned for a simple metric', () => {
+    const seriesCount = SUM_HINT_THRESHOLD_COUNT;
+    const series = Array.from({ length: seriesCount }, _ => ({
+      datapoints: [[0, 0], [0, 0]],
+    }));
+    const hints = getQueryHints('metric', series);
+    expect(hints.length).toBe(seriesCount);
+    expect(hints[0]).toMatchObject({
+      label: 'Many time series results returned.',
+      index: 0,
+      fix: {
+        action: {
+          type: 'ADD_SUM',
+          query: 'metric',
+        },
+      },
+    });
+  });
 });