Fix panic error due to rollDeleteOp ahead by load-and-delete (#20563)

issue:#20501
Signed-off-by: MrPresent-Han <jamesharden11122@gmail.com>

internal/datanode/buffer.go

@@ -115,7 +115,7 @@ func (bm *DelBufferManager) Load(segID UniqueID) (delDataBuf *DelDataBuf, ok boo
 	if ok {
 		return buffer, ok
 	}
-	return nil, ok
+	return nil, false
 }
 
 func (bm *DelBufferManager) Delete(segID UniqueID) {
@@ -127,14 +127,6 @@ func (bm *DelBufferManager) Delete(segID UniqueID) {
 	}
 }
 
-func (bm *DelBufferManager) LoadAndDelete(segID UniqueID) (delDataBuf *DelDataBuf, ok bool) {
-	if buf, ok := bm.Load(segID); ok {
-		bm.Delete(segID)
-		return buf, ok
-	}
-	return nil, ok
-}
-
 func (bm *DelBufferManager) CompactSegBuf(compactedToSegID UniqueID, compactedFromSegIDs []UniqueID) {
 	var compactToDelBuff *DelDataBuf
 	compactToDelBuff, loaded := bm.Load(compactedToSegID)
@@ -143,8 +135,9 @@ func (bm *DelBufferManager) CompactSegBuf(compactedToSegID UniqueID, compactedFr
 	}
 
 	for _, segID := range compactedFromSegIDs {
-		if delDataBuf, loaded := bm.LoadAndDelete(segID); loaded {
+		if delDataBuf, loaded := bm.Load(segID); loaded {
 			compactToDelBuff.mergeDelDataBuf(delDataBuf)
+			bm.Delete(segID)
 		}
 	}
 	// only store delBuf if EntriesNum > 0

internal/datanode/buffer_test.go

@@ -17,6 +17,7 @@
 package datanode
 
 import (
+	"container/heap"
 	"fmt"
 	"math"
 	"testing"
@@ -137,3 +138,46 @@ func TestBufferData_updateTimeRange(t *testing.T) {
 		})
 	}
 }
+
+func Test_CompactSegBuff(t *testing.T) {
+	channelSegments := make(map[UniqueID]*Segment)
+	delBufferManager := &DelBufferManager{
+		channel: &ChannelMeta{
+			segments: channelSegments,
+		},
+		delMemorySize: 0,
+		delBufHeap:    &PriorityQueue{},
+	}
+	//1. set compactTo and compactFrom
+	compactedFromSegIDs := make([]UniqueID, 2)
+	var segID1 UniqueID = 1111
+	var segID2 UniqueID = 2222
+	compactedFromSegIDs[0] = segID1
+	compactedFromSegIDs[1] = segID2
+	channelSegments[segID1] = &Segment{}
+	channelSegments[segID2] = &Segment{}
+	var compactedToSegID UniqueID = 3333
+	channelSegments[compactedToSegID] = &Segment{}
+
+	//2. set up deleteDataBuf for seg1 and seg2
+	delDataBuf1 := newDelDataBuf()
+	delDataBuf1.EntriesNum++
+	delBufferManager.Store(segID1, delDataBuf1)
+	heap.Push(delBufferManager.delBufHeap, delDataBuf1.item)
+	delDataBuf2 := newDelDataBuf()
+	delDataBuf2.EntriesNum++
+	delBufferManager.Store(segID2, delDataBuf2)
+	heap.Push(delBufferManager.delBufHeap, delDataBuf2.item)
+
+	//3. test compact
+	delBufferManager.CompactSegBuf(compactedToSegID, compactedFromSegIDs)
+
+	//4. expect results in two aspects:
+	//4.1 compactedFrom segments are removed from delBufferManager
+	//4.2 compactedTo seg is set properly with correct entriesNum
+	_, seg1Exist := delBufferManager.Load(segID1)
+	_, seg2Exist := delBufferManager.Load(segID2)
+	assert.False(t, seg1Exist)
+	assert.False(t, seg2Exist)
+	assert.Equal(t, int64(2), delBufferManager.GetEntriesNum(compactedToSegID))
+}

internal/datanode/flow_graph_delete_node.go

@@ -123,7 +123,6 @@ func (dn *deleteNode) Operate(in []Msg) []Msg {
 	//then we will add all segments in the fgMsg.segmentsToFlush into the toFlushSeg and remove duplicate segments
 	//the aim for taking all these actions is to guarantee that the memory consumed by delBuf will not exceed a limit
 	segmentsToFlush := dn.delBufferManager.ShouldFlushSegments()
-	log.Info("should flush segments, ", zap.Int("seg_count", len(segmentsToFlush)))
 	for _, msgSegmentID := range fgMsg.segmentsToSync {
 		existed := false
 		for _, autoFlushSegment := range segmentsToFlush {