fix #392. Different columns in different shards returns invalid results

CHANGELOG.md

@@ -7,6 +7,7 @@
 - [Issue #413](https://github.com/influxdb/influxdb/issues/413). Don't assume that group by interval is greater than a second
 - [Issue #415](https://github.com/influxdb/influxdb/issues/415). Include the database when sending an auth error back to the user
 - [Issue #421](https://github.com/influxdb/influxdb/issues/421). Make read timeout a config option
+- [Issue #392](https://github.com/influxdb/influxdb/issues/392). Different columns in different shards returns invalid results when a query spans those shards
 
 ### Bugfixes
 

src/api/http/api.go

@@ -214,7 +214,7 @@ func (self *AllPointsWriter) yield(series *protocol.Series) error {
 		return nil
 	}
 
-	oldSeries.Points = append(oldSeries.Points, series.Points...)
+	self.memSeries[series.GetName()] = MergeSeries(self.memSeries[series.GetName()], series)
 	return nil
 }
 

src/common/merge_series.go

@@ -0,0 +1,79 @@
+package common
+
+import (
+	"protocol"
+	"reflect"
+)
+
+func pointMaps(s *protocol.Series) (result []map[string]*protocol.FieldValue) {
+	for _, p := range s.Points {
+		pointMap := map[string]*protocol.FieldValue{}
+		for idx, value := range p.Values {
+			pointMap[s.Fields[idx]] = value
+		}
+		result = append(result, pointMap)
+	}
+	return
+}
+
+// merges two time series making sure that the resulting series has
+// the union of the two series columns and the values set
+// properly. will panic if the two series don't have the same name
+func MergeSeries(s1, s2 *protocol.Series) *protocol.Series {
+	if s1.GetName() != s1.GetName() {
+		panic("the two series don't have the same name")
+	}
+
+	// if the two series have the same columns and in the same order
+	// append the points and return.
+	if reflect.DeepEqual(s1.Fields, s2.Fields) {
+		s1.Points = append(s1.Points, s2.Points...)
+		return s1
+	}
+
+	columns := map[string]struct{}{}
+
+	for _, cs := range [][]string{s1.Fields, s2.Fields} {
+		for _, c := range cs {
+			columns[c] = struct{}{}
+		}
+	}
+
+	points := append(pointMaps(s1), pointMaps(s2)...)
+
+	fieldsSlice := make([]string, 0, len(columns))
+	for c, _ := range columns {
+		fieldsSlice = append(fieldsSlice, c)
+	}
+
+	resultPoints := make([]*protocol.Point, 0, len(points))
+	for idx, point := range points {
+		resultPoint := &protocol.Point{}
+		for _, field := range fieldsSlice {
+			value := point[field]
+			if value == nil {
+				value = &protocol.FieldValue{
+					IsNull: &TRUE,
+				}
+			}
+			resultPoint.Values = append(resultPoint.Values, value)
+			if idx < len(s1.Points) {
+				resultPoint.Timestamp = s1.Points[idx].Timestamp
+				resultPoint.SequenceNumber = s1.Points[idx].SequenceNumber
+			} else {
+				resultPoint.Timestamp = s2.Points[idx-len(s1.Points)].Timestamp
+				resultPoint.SequenceNumber = s2.Points[idx-len(s1.Points)].SequenceNumber
+			}
+		}
+		resultPoints = append(resultPoints, resultPoint)
+	}
+
+	// otherwise, merge the columns
+	result := &protocol.Series{
+		Name:   s1.Name,
+		Fields: fieldsSlice,
+		Points: resultPoints,
+	}
+
+	return result
+}

src/common/serialize_series.go

@@ -6,7 +6,10 @@ import (
 	"regexp"
 )
 
-var TRUE = true
+var (
+	TRUE  = true
+	FALSE = false
+)
 
 type TimePrecision int
 

src/engine/passthrough_engine.go

@@ -3,8 +3,10 @@ package engine
 // This engine buffers points and passes them through without modification. Works for queries
 // that can't be aggregated locally or queries that don't require it like deletes and drops.
 import (
-	log "code.google.com/p/log4go"
+	"common"
 	"protocol"
+
+	log "code.google.com/p/log4go"
 )
 
 type PassthroughEngine struct {
@@ -45,34 +47,8 @@ func NewPassthroughEngineWithLimit(responseChan chan *protocol.Response, maxPoin
 }
 
 func (self *PassthroughEngine) YieldPoint(seriesName *string, columnNames []string, point *protocol.Point) bool {
-	self.responseType = &queryResponse
 	series := &protocol.Series{Name: seriesName, Points: []*protocol.Point{point}, Fields: columnNames}
-	self.limiter.calculateLimitAndSlicePoints(series)
-	if len(series.Points) == 0 {
-		return false
-	}
-
-	if self.response == nil {
-		self.response = &protocol.Response{
-			Type:   self.responseType,
-			Series: series,
-		}
-	} else if *self.response.Series.Name != *seriesName {
-		self.responseChan <- self.response
-		self.response = &protocol.Response{
-			Type:   self.responseType,
-			Series: series,
-		}
-	} else if len(self.response.Series.Points) > self.maxPointsInResponse {
-		self.responseChan <- self.response
-		self.response = &protocol.Response{
-			Type:   self.responseType,
-			Series: series,
-		}
-	} else {
-		self.response.Series.Points = append(self.response.Series.Points, point)
-	}
-	return !self.limiter.hitLimit(*seriesName)
+	return self.YieldSeries(series)
 }
 
 func (self *PassthroughEngine) YieldSeries(seriesIncoming *protocol.Series) bool {
@@ -108,7 +84,7 @@ func (self *PassthroughEngine) YieldSeries(seriesIncoming *protocol.Series) bool
 			Series: seriesIncoming,
 		}
 	} else {
-		self.response.Series.Points = append(self.response.Series.Points, seriesIncoming.Points...)
+		self.response.Series = common.MergeSeries(self.response.Series, seriesIncoming)
 	}
 	return !self.limiter.hitLimit(seriesIncoming.GetName())
 	//return true