Loki: Fix metric time splitting to split starting with the start time (#80085)

* Loki: Fix metric time splitting to split starting with the start time

* add test case to gdev-dashboard

* fix splitting test

devenv/dev-dashboards/datasource-loki/loki_query_splitting.json

@@ -18,7 +18,6 @@
   "editable": true,
   "fiscalYearStartMonth": 0,
   "graphTooltip": 0,
-    "id": 7004,
   "links": [],
   "liveNow": false,
   "panels": [
@@ -221,7 +220,8 @@
                 "value": 80
               }
             ]
-            }
+          },
+          "unitScale": true
         },
         "overrides": []
       },
@@ -315,7 +315,8 @@
                 "value": 80
               }
             ]
-            }
+          },
+          "unitScale": true
         },
         "overrides": []
       },
@@ -496,7 +497,8 @@
                 "value": 80
               }
             ]
-            }
+          },
+          "unitScale": true
         },
         "overrides": []
       },
@@ -519,7 +521,7 @@
         },
         "showHeader": true
       },
-        "pluginVersion": "10.2.0-61469",
+      "pluginVersion": "10.3.0-pre",
       "targets": [
         {
           "datasource": {
@@ -588,7 +590,8 @@
                 "value": 80
               }
             ]
-            }
+          },
+          "unitScale": true
         },
         "overrides": []
       },
@@ -611,7 +614,7 @@
         },
         "showHeader": true
       },
-        "pluginVersion": "10.2.0-61469",
+      "pluginVersion": "10.3.0-pre",
       "targets": [
         {
           "datasource": {
@@ -680,7 +683,8 @@
                 "value": 80
               }
             ]
-            }
+          },
+          "unitScale": true
         },
         "overrides": []
       },
@@ -703,7 +707,7 @@
         },
         "showHeader": true
       },
-        "pluginVersion": "10.2.0-61469",
+      "pluginVersion": "10.3.0-pre",
       "targets": [
         {
           "datasource": {
@@ -795,7 +799,8 @@
                 "value": 80
               }
             ]
-            }
+          },
+          "unitScale": true
         },
         "overrides": []
       },
@@ -818,7 +823,7 @@
         },
         "showHeader": true
       },
-        "pluginVersion": "10.2.0-61469",
+      "pluginVersion": "10.3.0-pre",
       "targets": [
         {
           "datasource": {
@@ -879,22 +884,256 @@
         }
       ],
       "type": "table"
+    },
+    {
+      "datasource": {
+        "type": "loki",
+        "uid": "PDDA8E780A17E7EF1"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "custom": {
+            "align": "auto",
+            "cellOptions": {
+              "type": "auto"
+            },
+            "inspect": false
+          },
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ]
+          },
+          "unitScale": true
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 36
+      },
+      "id": 11,
+      "options": {
+        "cellHeight": "sm",
+        "footer": {
+          "countRows": false,
+          "fields": "",
+          "reducer": [
+            "sum"
+          ],
+          "show": false
+        },
+        "showHeader": true
+      },
+      "pluginVersion": "10.3.0-pre",
+      "targets": [
+        {
+          "datasource": {
+            "type": "loki",
+            "uid": "gdev-loki"
+          },
+          "editorMode": "code",
+          "expr": "sum(count_over_time({place=\"moon\"}[$__auto]))",
+          "maxLines": 5,
+          "queryType": "range",
+          "refId": "A",
+          "step": "1d"
+        }
+      ],
+      "title": "Metric 1d step",
+      "transformations": [
+        {
+          "id": "extractFields",
+          "options": {
+            "format": "auto",
+            "keepTime": true,
+            "replace": true,
+            "source": "Line"
+          }
+        },
+        {
+          "id": "organize",
+          "options": {
+            "excludeByName": {
+              "31": true,
+              "32": true,
+              "33": true,
+              "34": true,
+              "35": true,
+              "36": true,
+              "37": true,
+              "38": true,
+              "39": true,
+              "40": true,
+              "41": true,
+              "42": true,
+              "43": true,
+              "44": true,
+              "45": true,
+              "46": true,
+              "2023-09-20T14": true,
+              "33+00": true,
+              "caller": true,
+              "main.go": true,
+              "t": true,
+              "ts": true
+            },
+            "indexByName": {},
+            "renameByName": {
+              "level": "nivel",
+              "ts": ""
+            }
+          }
+        }
+      ],
+      "type": "table"
+    },
+    {
+      "datasource": {
+        "type": "loki",
+        "uid": "PDDA8E780A17E7EF1"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "custom": {
+            "align": "auto",
+            "cellOptions": {
+              "type": "auto"
+            },
+            "inspect": false
+          },
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ]
+          },
+          "unitScale": true
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 36
+      },
+      "id": 12,
+      "options": {
+        "cellHeight": "sm",
+        "footer": {
+          "countRows": false,
+          "fields": "",
+          "reducer": [
+            "sum"
+          ],
+          "show": false
+        },
+        "showHeader": true
+      },
+      "pluginVersion": "10.3.0-pre",
+      "targets": [
+        {
+          "datasource": {
+            "type": "loki",
+            "uid": "gdev-loki"
+          },
+          "editorMode": "code",
+          "expr": "sum(count_over_time({place=\"moon\"}[$__auto]))",
+          "maxLines": 5,
+          "queryType": "range",
+          "refId": "do-not-chunk",
+          "step": "1d"
+        }
+      ],
+      "title": "Metric 1d step, no splitting",
+      "transformations": [
+        {
+          "id": "extractFields",
+          "options": {
+            "format": "auto",
+            "keepTime": true,
+            "replace": true,
+            "source": "Line"
+          }
+        },
+        {
+          "id": "organize",
+          "options": {
+            "excludeByName": {
+              "31": true,
+              "32": true,
+              "33": true,
+              "34": true,
+              "35": true,
+              "36": true,
+              "37": true,
+              "38": true,
+              "39": true,
+              "40": true,
+              "41": true,
+              "42": true,
+              "43": true,
+              "44": true,
+              "45": true,
+              "46": true,
+              "2023-09-20T14": true,
+              "33+00": true,
+              "caller": true,
+              "main.go": true,
+              "t": true,
+              "ts": true
+            },
+            "indexByName": {},
+            "renameByName": {
+              "level": "nivel",
+              "ts": ""
+            }
+          }
+        }
+      ],
+      "type": "table"
     }
   ],
   "refresh": "",
-    "schemaVersion": 38,
+  "schemaVersion": 39,
   "tags": [],
   "templating": {
     "list": []
   },
   "time": {
-      "from": "now-6h",
+    "from": "now-5m",
     "to": "now"
   },
   "timepicker": {},
   "timezone": "",
   "title": "Datasource tests - Loki query splitting",
   "uid": "dc4ec947-7e6b-4c3b-be8f-0abec7b0652a",
-    "version": 13,
+  "version": 2,
   "weekStart": ""
 }

public/app/plugins/datasource/loki/metricTimeSplitting.test.ts

@@ -1,15 +1,55 @@
 import { splitTimeRange } from './metricTimeSplitting';
 
 describe('metric splitTimeRange', () => {
-  it('should split time range into chunks', () => {
+  it('should split time range into chunks with 1day split and duration', () => {
-    const start = Date.parse('2022-02-06T14:10:03');
+    const start = Date.parse('2022-02-06T14:10:03Z');
-    const end = Date.parse('2022-02-06T14:11:03');
+    const end = Date.parse('2022-02-08T14:11:03Z');
-    const step = 10 * 1000;
+    const step = 24 * 60 * 60 * 1000; // 1 day
+    const rangeDuration = 24 * 60 * 60 * 1000; // 1 day
 
-    expect(splitTimeRange(start, end, step, 25000)).toStrictEqual([
+    expect(splitTimeRange(start, end, step, rangeDuration)).toStrictEqual([
-      [Date.parse('2022-02-06T14:10:00'), Date.parse('2022-02-06T14:10:10')],
+      [Date.parse('2022-02-06T00:00:00Z'), Date.parse('2022-02-06T00:00:00Z')],
-      [Date.parse('2022-02-06T14:10:20'), Date.parse('2022-02-06T14:10:40')],
+      [Date.parse('2022-02-07T00:00:00Z'), Date.parse('2022-02-07T00:00:00Z')],
-      [Date.parse('2022-02-06T14:10:50'), Date.parse('2022-02-06T14:11:10')],
+      [Date.parse('2022-02-08T00:00:00Z'), Date.parse('2022-02-08T00:00:00Z')],
+    ]);
+  });
+
+  it('should split time range into chunks with 1day split and duration and a 5 minute duration', () => {
+    const start = Date.parse('2022-02-06T14:00:00Z');
+    const end = Date.parse('2022-02-06T14:05:00Z');
+    const step = 24 * 60 * 60 * 1000; // 1 day
+    const rangeDuration = 24 * 60 * 60 * 1000; // 1 day
+
+    expect(splitTimeRange(start, end, step, rangeDuration)).toStrictEqual([
+      [Date.parse('2022-02-06T00:00:00Z'), Date.parse('2022-02-06T00:00:00Z')],
+    ]);
+  });
+
+  it('should split time range into chunks with 1hour split and 1day duration', () => {
+    const start = Date.parse('2022-02-06T14:10:03Z');
+    const end = Date.parse('2022-02-08T14:11:03Z');
+    const step = 60 * 60 * 1000; // 1 hour
+    const rangeDuration = 24 * 60 * 60 * 1000; // 1 day
+
+    expect(splitTimeRange(start, end, step, rangeDuration)).toStrictEqual([
+      [Date.parse('2022-02-06T14:00:00Z'), Date.parse('2022-02-07T13:00:00Z')],
+      [Date.parse('2022-02-07T14:00:00Z'), Date.parse('2022-02-08T13:00:00Z')],
+      [Date.parse('2022-02-08T14:00:00Z'), Date.parse('2022-02-08T14:11:03Z')],
+    ]);
+  });
+
+  it('should split time range into chunks with 1hour split and 12h duration', () => {
+    const start = Date.parse('2022-02-06T14:10:03Z');
+    const end = Date.parse('2022-02-08T14:11:03Z');
+    const step = 60 * 60 * 1000; // 1 hour
+    const rangeDuration = 12 * 60 * 60 * 1000; // 12h
+
+    expect(splitTimeRange(start, end, step, rangeDuration)).toStrictEqual([
+      [Date.parse('2022-02-06T14:00:00Z'), Date.parse('2022-02-07T01:00:00Z')],
+      [Date.parse('2022-02-07T02:00:00Z'), Date.parse('2022-02-07T13:00:00Z')],
+      [Date.parse('2022-02-07T14:00:00Z'), Date.parse('2022-02-08T01:00:00Z')],
+      [Date.parse('2022-02-08T02:00:00Z'), Date.parse('2022-02-08T13:00:00Z')],
+      [Date.parse('2022-02-08T14:00:00Z'), Date.parse('2022-02-08T14:11:03Z')],
     ]);
   });
 

public/app/plugins/datasource/loki/metricTimeSplitting.ts

@@ -5,20 +5,6 @@
 // we are trying to be compatible with
 // https://github.com/grafana/loki/blob/089ec1b05f5ec15a8851d0e8230153e0eeb4dcec/pkg/querier/queryrange/split_by_interval.go#L327-L336
 
-function expandTimeRange(startTime: number, endTime: number, step: number): [number, number] {
-  // startTime is decreased to the closes multiple-of-step, if necessary
-  const newStartTime = startTime - (startTime % step);
-
-  // endTime is increased to the closed multiple-of-step, if necessary
-  let newEndTime = endTime;
-  const endStepMod = endTime % step;
-  if (endStepMod !== 0) {
-    newEndTime += step - endStepMod;
-  }
-
-  return [newStartTime, newEndTime];
-}
-
 export function splitTimeRange(
   startTime: number,
   endTime: number,
@@ -33,20 +19,19 @@ export function splitTimeRange(
   // we make the duration a multiple of `step`, lowering it if necessary
   const alignedDuration = Math.trunc(idealRangeDuration / step) * step;
 
-  const [alignedStartTime, alignedEndTime] = expandTimeRange(startTime, endTime, step);
+  const alignedStartTime = startTime - (startTime % step);
 
   const result: Array<[number, number]> = [];
 
-  // we iterate it from the end, because we want to have the potentially smaller chunk at the end, not at the beginning
+  // in a previous version we started iterating from the end, to the start.
-  for (let chunkEndTime = alignedEndTime; chunkEndTime > alignedStartTime; chunkEndTime -= alignedDuration + step) {
+  // However this is not easily possible as end timestamps are always inclusive
-    // when we get close to the start of the time range, we need to be sure not
+  // for Loki. So a `2022-02-08T00:00:00Z` end time with a 1day step would mean
-    // to cross over the startTime
+  // to include the 08.02.2022, which we don't want. So we have to start from
-    const chunkStartTime = Math.max(chunkEndTime - alignedDuration, alignedStartTime);
+  // the start, always ending at the last step before the actual end, or the total end.
+  for (let chunkStartTime = alignedStartTime; chunkStartTime < endTime; chunkStartTime += alignedDuration) {
+    const chunkEndTime = Math.min(chunkStartTime + alignedDuration - step, endTime);
     result.push([chunkStartTime, chunkEndTime]);
   }
 
-  // because we walked backwards, we need to reverse the array
-  result.reverse();
-
   return result;
 }

public/app/plugins/datasource/loki/querySplitting.test.ts

@@ -82,8 +82,8 @@ describe('runSplitQuery()', () => {
           intervalMs: 60000,
           range: expect.objectContaining({
             from: expect.objectContaining({
-              //2023-02-09T06:00:00.000Z
+              //2023-02-10T05:00:00.000Z
-              _i: 1675922400000,
+              _i: 1676005200000,
             }),
             to: expect.objectContaining({
               // 2023-02-10T06:00:00.000Z
@@ -100,12 +100,12 @@ describe('runSplitQuery()', () => {
           intervalMs: 60000,
           range: expect.objectContaining({
             from: expect.objectContaining({
-              //2023-02-08T05:59:00.000Z
+              // 2023-02-09T05:00:00.000Z
-              _i: 1675835940000,
+              _i: 1675918800000,
             }),
             to: expect.objectContaining({
-              // 2023-02-09T05:59:00.000Z
+              // 2023-02-10T04:59:00.000Z
-              _i: 1675922340000,
+              _i: 1676005140000,
             }),
           }),
         })
@@ -122,8 +122,8 @@ describe('runSplitQuery()', () => {
               _i: 1675832400000,
             }),
             to: expect.objectContaining({
-              // 2023-02-08T05:58:00.000Z
+              // 2023-02-09T04:59:00.000Z
-              _i: 1675835880000,
+              _i: 1675918740000,
             }),
           }),
         })
@@ -142,8 +142,8 @@ describe('runSplitQuery()', () => {
           intervalMs: 60000,
           range: expect.objectContaining({
             from: expect.objectContaining({
-              //2023-02-09T06:00:00.000Z
+              //2023-02-10T05:00:00.000Z
-              _i: 1675922400000,
+              _i: 1676005200000,
             }),
             to: expect.objectContaining({
               // 2023-02-10T06:00:00.000Z
@@ -160,12 +160,12 @@ describe('runSplitQuery()', () => {
           intervalMs: 60000,
           range: expect.objectContaining({
             from: expect.objectContaining({
-              //2023-02-08T05:59:50.000Z
+              // 2023-02-09T05:00:00.000Z
-              _i: 1675835990000,
+              _i: 1675918800000,
             }),
             to: expect.objectContaining({
-              // 2023-02-09T05:59:50.000Z
+              // 2023-02-10T04:59:50.000Z
-              _i: 1675922390000,
+              _i: 1676005190000,
             }),
           }),
         })
@@ -182,8 +182,8 @@ describe('runSplitQuery()', () => {
               _i: 1675832400000,
             }),
             to: expect.objectContaining({
-              // 2023-02-08T05:59:40.000Z
+              // 2023-02-09T04:59:50.000Z
-              _i: 1675835980000,
+              _i: 1675918790000,
             }),
           }),
         })