Fix invalid single compaction (#21328)

Signed-off-by: xige-16 <xi.ge@zilliz.com>

configs/milvus.yaml

@@ -281,7 +281,7 @@ dataCoord:
     minSizeFromIdleToSealed: 16 # The min size in MB of segment which can be idle from sealed.
     smallProportion: 0.5 # The segment is considered as "small segment" when its # of rows is smaller than
     # (smallProportion * segment max # of rows).
-    compactableProportion: 0.5 # A compaction will happen on small segments if the segment after compaction will have
+    compactableProportion: 0.85 # A compaction will happen on small segments if the segment after compaction will have
     # over (compactableProportion * segment max # of rows) rows.
     # MUST BE GREATER THAN OR EQUAL TO <smallProportion>!!!
 

internal/util/paramtable/component_param.go

@@ -1255,8 +1255,7 @@ func (p *dataCoordConfig) init(base *BaseTable) {
 
 	p.initCompactionMinSegment()
 	p.initCompactionMaxSegment()
-	p.initSegmentSmallProportion()
-	p.initSegmentCompactableProportion()
+	p.initSegmentProportion()
 	p.initCompactionTimeoutInSeconds()
 	p.initCompactionCheckIntervalInSeconds()
 	p.initSingleCompactionRatioThreshold()
@@ -1333,7 +1332,17 @@ func (p *dataCoordConfig) initSegmentSmallProportion() {
 }
 
 func (p *dataCoordConfig) initSegmentCompactableProportion() {
-	p.SegmentCompactableProportion = p.Base.ParseFloatWithDefault("dataCoord.segment.compactableProportion", 0.5)
+	p.SegmentCompactableProportion = p.Base.ParseFloatWithDefault("dataCoord.segment.compactableProportion", 0.85)
+}
+
+func (p *dataCoordConfig) initSegmentProportion() {
+	p.initSegmentSmallProportion()
+	p.initSegmentCompactableProportion()
+
+	// avoid invalid single compaction
+	if p.SegmentCompactableProportion < p.SegmentSmallProportion {
+		p.SegmentCompactableProportion = p.SegmentSmallProportion
+	}
 }
 
 // compaction execution timeout

internal/util/paramtable/component_param_test.go

@@ -290,6 +290,7 @@ func TestComponentParam(t *testing.T) {
 		assert.Equal(t, 24*60*60*time.Second, Params.SegmentMaxLifetime)
 		assert.True(t, Params.EnableGarbageCollection)
 		assert.Equal(t, Params.EnableActiveStandby, false)
+		assert.True(t, Params.SegmentCompactableProportion >= Params.SegmentSmallProportion)
 		t.Logf("dataCoord EnableActiveStandby = %t", Params.EnableActiveStandby)
 	})