Fix Distributed Query Bug

CHANGES.md

@@ -31,6 +31,7 @@ Release Notes.
 - Fix the wrong array flags parsing in command line. The array flags should be parsed by "StringSlice" instead of "StringArray".
 - Fix a bug that the Stream module didn't support duplicated in index-based filtering and sorting
 - Fix the bug that segment's reference count is increased twice when the controller try to create an existing segment.
+- Fix a bug where a distributed query would return an empty result if the "limit" was set much lower than the "offset".
 
 ### Documentation
 - Introduce new doc menu structure.

pkg/query/logical/measure/measure_plan_distributed.go

@@ -87,7 +87,7 @@ func (ud *unresolvedDistributed) Analyze(s logical.Schema) (logical.Plan, error)
 		Name:            ud.originalQuery.Name,
 		Groups:          ud.originalQuery.Groups,
 		Criteria:        ud.originalQuery.Criteria,
-		Limit:           limit,
+		Limit:           limit + ud.originalQuery.Offset,
 		OrderBy:         ud.originalQuery.OrderBy,
 	}
 	if ud.groupByEntity {

pkg/query/logical/stream/stream_plan_distributed.go

@@ -74,7 +74,7 @@ func (ud *unresolvedDistributed) Analyze(s logical.Schema) (logical.Plan, error)
 		Name:       ud.originalQuery.Name,
 		Groups:     ud.originalQuery.Groups,
 		Criteria:   ud.originalQuery.Criteria,
-		Limit:      limit,
+		Limit:      limit + ud.originalQuery.Offset,
 		OrderBy:    ud.originalQuery.OrderBy,
 	}
 	if ud.originalQuery.OrderBy == nil {

test/cases/measure/data/input/limit.yaml

@@ -23,5 +23,5 @@ tagProjection:
     tags: ["entity_id"]
 fieldProjection:
   names: ["total", "value"]
-limit: 2
+limit: 1
 offset: 3

test/cases/measure/data/want/limit.yaml

@@ -33,20 +33,3 @@ dataPoints:
         str:
           value: entity_4
   timestamp: "2023-06-26T01:01:00Z"
-- fields:
-  - name: total
-    value:
-      int:
-        value: "50"
-  - name: value
-    value:
-      int:
-        value: "4"
-  tagFamilies:
-  - name: default
-    tags:
-    - key: entity_id
-      value:
-        str:
-          value: entity_5
-  timestamp: "2023-06-26T01:02:00Z"

test/cases/stream/data/input/offset.yaml

@@ -24,3 +24,4 @@ projection:
   - name: "data"
     tags: ["data_binary"]
 offset: 3
+limit: 1

test/cases/stream/data/want/offset.yaml

@@ -16,29 +16,17 @@
 # under the License.
 
 elements:
-  - elementId: "3"
-    tagFamilies:
-    - name: searchable
-      tags:
-      - key: trace_id
-        value:
-          str:
-            value: "4"
-    - name: data
-      tags:
-      - key: data_binary
-        value:
-          binaryData: YWJjMTIzIT8kKiYoKSctPUB+
-  - elementId: "4"
-    tagFamilies:
-    - name: searchable
-      tags:
-      - key: trace_id
-        value:
-          str:
-            value: "5"
-    - name: data
-      tags:
-      - key: data_binary
-        value:
-          binaryData: YWJjMTIzIT8kKiYoKSctPUB+
+- elementId: "3"
+  tagFamilies:
+  - name: searchable
+    tags:
+    - key: trace_id
+      value:
+        str:
+          value: "4"
+  - name: data
+    tags:
+    - key: data_binary
+      value:
+        binaryData: YWJjMTIzIT8kKiYoKSctPUB+
+