func (self *ShardData) getProcessor(querySpec *parser.QuerySpec, processor engine.Processor) (engine.Processor, error) {
switch qt := querySpec.Query().Type(); qt {
case parser.Delete, parser.DropSeries:
return NilProcessor{}, nil
case parser.Select:
// continue
default:
panic(fmt.Errorf("Unexpected query type: %s", qt))
}
if querySpec.IsSinglePointQuery() {
return engine.NewPassthroughEngine(processor, 1), nil
}
query := querySpec.SelectQuery()
var err error
// We should aggregate at the shard level
if self.ShouldAggregateLocally(querySpec) {
log.Debug("creating a query engine")
processor, err = engine.NewQueryEngine(processor, query, nil)
if err != nil {
return nil, err
}
goto addFilter
}
// we shouldn't limit the queries if they have aggregates and aren't
// aggregated locally, otherwise the aggregation result which happen
// in the coordinator will get partial data and will be incorrect
if query.HasAggregates() {
log.Debug("creating a passthrough engine")
processor = engine.NewPassthroughEngine(processor, 1000)
goto addFilter
}
// This is an optimization so we don't send more data that we should
// over the wire. The coordinator has its own Passthrough which does
// the final limit.
if l := query.Limit; l > 0 {
log.Debug("creating a passthrough engine with limit")
processor = engine.NewPassthroughEngineWithLimit(processor, 1000, query.Limit)
}
addFilter:
if query := querySpec.SelectQuery(); query != nil && query.GetFromClause().Type != parser.FromClauseInnerJoin {
// Joins do their own filtering since we need to get all
// points before filtering. This is due to the fact that some
// where expressions will be difficult to compute before the
// points are joined together, think where clause with
// left.column = 'something' or right.column =
// 'something_else'. We can't filter the individual series
// separately. The filtering happens in merge.go:55
processor = engine.NewFilteringEngine(query, processor)
}
return processor, nil
}
func (self *Shard) executeQueryForSeries(querySpec *parser.QuerySpec, seriesName string, columns []string, processor engine.Processor) error {
fields, err := self.getFieldsForSeries(querySpec.Database(), seriesName, columns)
if err != nil {
log.Error("Error looking up fields for %s: %s", seriesName, err)
return err
}
if querySpec.IsSinglePointQuery() {
log.Debug("Running single query for series %s, fields %v", seriesName, fields)
return self.executeSinglePointQuery(querySpec, seriesName, fields, processor)
}
startTime := querySpec.GetStartTime()
endTime := querySpec.GetEndTime()
query := querySpec.SelectQuery()
aliases := query.GetTableAliases(seriesName)
fieldNames, iterators := self.getIterators(fields, startTime, endTime, query.Ascending)
seriesOutgoing := &protocol.Series{Name: protocol.String(seriesName), Fields: fieldNames, Points: make([]*protocol.Point, 0, self.pointBatchSize)}
pi := NewPointIterator(iterators, fields, querySpec.GetStartTime(), querySpec.GetEndTime(), query.Ascending)
defer pi.Close()
for pi.Valid() {
p := pi.Point()
seriesOutgoing.Points = append(seriesOutgoing.Points, p)
if len(seriesOutgoing.Points) >= self.pointBatchSize {
ok, err := yieldToProcessor(seriesOutgoing, processor, aliases)
if !ok || err != nil {
log.Debug("Stopping processing.")
if err != nil {
log.Error("Error while processing data: %v", err)
return err
}
}
seriesOutgoing = &protocol.Series{Name: protocol.String(seriesName), Fields: fieldNames, Points: make([]*protocol.Point, 0, self.pointBatchSize)}
}
pi.Next()
}
if err := pi.Error(); err != nil {
return err
}
//Yield remaining data
if ok, err := yieldToProcessor(seriesOutgoing, processor, aliases); !ok || err != nil {
log.Debug("Stopping processing remaining points...")
if err != nil {
log.Error("Error while processing data: %v", err)
return err
}
}
log.Debug("Finished running query %s", query.GetQueryString())
return nil
}
func (self *Shard) executeQueryForSeries(querySpec *parser.QuerySpec, name string, columns []string, processor engine.Processor) error {
if querySpec.IsSinglePointQuery() {
log.Debug("Running single query for series %s", name)
return self.executeSinglePointQuery(querySpec, name, columns, processor)
}
var pi *PointIterator
var err error
columns, pi, err = self.getPointIteratorForSeries(querySpec, name, columns)
if err != nil {
return err
}
defer pi.Close()
query := querySpec.SelectQuery()
aliases := query.GetTableAliases(name)
seriesOutgoing := &protocol.Series{Name: protocol.String(name), Fields: columns, Points: make([]*protocol.Point, 0, self.pointBatchSize)}
for pi.Valid() {
p := pi.Point()
seriesOutgoing.Points = append(seriesOutgoing.Points, p)
if len(seriesOutgoing.Points) >= self.pointBatchSize {
ok, err := yieldToProcessor(seriesOutgoing, processor, aliases)
if !ok || err != nil {
log.Debug("Stopping processing.")
if err != nil {
log.Error("Error while processing data: %v", err)
return err
}
return nil
}
seriesOutgoing = &protocol.Series{Name: protocol.String(name), Fields: columns, Points: make([]*protocol.Point, 0, self.pointBatchSize)}
}
pi.Next()
}
if err := pi.Error(); err != nil {
return err
}
//Yield remaining data
if ok, err := yieldToProcessor(seriesOutgoing, processor, aliases); !ok || err != nil {
log.Debug("Stopping processing remaining points...")
if err != nil {
log.Error("Error while processing data: %v", err)
return err
}
}
log.Debug("Finished running query %s", query.GetQueryString())
return nil
}
func (self *Shard) executeQueryForSeries(querySpec *parser.QuerySpec, seriesName string, columns []string, processor cluster.QueryProcessor) error {
startTimeBytes := self.byteArrayForTime(querySpec.GetStartTime())
endTimeBytes := self.byteArrayForTime(querySpec.GetEndTime())
fields, err := self.getFieldsForSeries(querySpec.Database(), seriesName, columns)
if err != nil {
log.Error("Error looking up fields for %s: %s", seriesName, err)
return err
}
fieldCount := len(fields)
rawColumnValues := make([]rawColumnValue, fieldCount, fieldCount)
query := querySpec.SelectQuery()
aliases := query.GetTableAliases(seriesName)
if querySpec.IsSinglePointQuery() {
series, err := self.fetchSinglePoint(querySpec, seriesName, fields)
if err != nil {
log.Error("Error reading a single point: %s", err)
return err
}
if len(series.Points) > 0 {
processor.YieldPoint(series.Name, series.Fields, series.Points[0])
}
return nil
}
fieldNames, iterators := self.getIterators(fields, startTimeBytes, endTimeBytes, query.Ascending)
defer func() {
for _, it := range iterators {
it.Close()
}
}()
seriesOutgoing := &protocol.Series{Name: protocol.String(seriesName), Fields: fieldNames, Points: make([]*protocol.Point, 0, self.pointBatchSize)}
// TODO: clean up, this is super gnarly
// optimize for the case where we're pulling back only a single column or aggregate
buffer := bytes.NewBuffer(nil)
valueBuffer := proto.NewBuffer(nil)
for {
isValid := false
point := &protocol.Point{Values: make([]*protocol.FieldValue, fieldCount, fieldCount)}
for i, it := range iterators {
if rawColumnValues[i].value != nil || !it.Valid() {
if err := it.Error(); err != nil {
return err
}
continue
}
key := it.Key()
if len(key) < 16 {
continue
}
if !isPointInRange(fields[i].IdAsBytes(), startTimeBytes, endTimeBytes, key) {
continue
}
value := it.Value()
sequenceNumber := key[16:]
rawTime := key[8:16]
rawColumnValues[i] = rawColumnValue{time: rawTime, sequence: sequenceNumber, value: value}
}
var pointTimeRaw []byte
var pointSequenceRaw []byte
// choose the highest (or lowest in case of ascending queries) timestamp
// and sequence number. that will become the timestamp and sequence of
// the next point.
for _, value := range rawColumnValues {
if value.value == nil {
continue
}
pointTimeRaw, pointSequenceRaw = value.updatePointTimeAndSequence(pointTimeRaw,
pointSequenceRaw, query.Ascending)
}
for i, iterator := range iterators {
// if the value is nil or doesn't match the point's timestamp and sequence number
// then skip it
if rawColumnValues[i].value == nil ||
!bytes.Equal(rawColumnValues[i].time, pointTimeRaw) ||
!bytes.Equal(rawColumnValues[i].sequence, pointSequenceRaw) {
point.Values[i] = &protocol.FieldValue{IsNull: &TRUE}
continue
}
// if we emitted at lease one column, then we should keep
// trying to get more points
isValid = true
// advance the iterator to read a new value in the next iteration
if query.Ascending {
iterator.Next()
} else {
iterator.Prev()
}
fv := &protocol.FieldValue{}
valueBuffer.SetBuf(rawColumnValues[i].value)
err := valueBuffer.Unmarshal(fv)
if err != nil {
log.Error("Error while running query: %s", err)
return err
}
point.Values[i] = fv
rawColumnValues[i].value = nil
}
var sequence uint64
var t uint64
// set the point sequence number and timestamp
buffer.Reset()
buffer.Write(pointSequenceRaw)
binary.Read(buffer, binary.BigEndian, &sequence)
buffer.Reset()
buffer.Write(pointTimeRaw)
binary.Read(buffer, binary.BigEndian, &t)
time := self.convertUintTimestampToInt64(&t)
point.SetTimestampInMicroseconds(time)
point.SequenceNumber = &sequence
// stop the loop if we ran out of points
if !isValid {
break
}
shouldContinue := true
seriesOutgoing.Points = append(seriesOutgoing.Points, point)
if len(seriesOutgoing.Points) >= self.pointBatchSize {
for _, alias := range aliases {
series := &protocol.Series{
Name: proto.String(alias),
Fields: fieldNames,
Points: seriesOutgoing.Points,
}
if !processor.YieldSeries(series) {
log.Info("Stopping processing")
shouldContinue = false
}
}
seriesOutgoing = &protocol.Series{Name: protocol.String(seriesName), Fields: fieldNames, Points: make([]*protocol.Point, 0, self.pointBatchSize)}
}
if !shouldContinue {
break
}
}
//Yield remaining data
for _, alias := range aliases {
log.Debug("Final Flush %s", alias)
series := &protocol.Series{Name: protocol.String(alias), Fields: seriesOutgoing.Fields, Points: seriesOutgoing.Points}
if !processor.YieldSeries(series) {
log.Debug("Cancelled...")
}
}
log.Debug("Finished running query %s", query.GetQueryString())
return nil
}
func (self *ShardData) Query(querySpec *parser.QuerySpec, response chan *p.Response) {
log.Debug("QUERY: shard %d, query '%s'", self.Id(), querySpec.GetQueryString())
defer common.RecoverFunc(querySpec.Database(), querySpec.GetQueryString(), func(err interface{}) {
response <- &p.Response{Type: &endStreamResponse, ErrorMessage: p.String(fmt.Sprintf("%s", err))}
})
// This is only for queries that are deletes or drops. They need to be sent everywhere as opposed to just the local or one of the remote shards.
// But this boolean should only be set to true on the server that receives the initial query.
if querySpec.RunAgainstAllServersInShard {
if querySpec.IsDeleteFromSeriesQuery() {
self.logAndHandleDeleteQuery(querySpec, response)
} else if querySpec.IsDropSeriesQuery() {
self.logAndHandleDropSeriesQuery(querySpec, response)
}
}
if self.IsLocal {
var processor QueryProcessor
var err error
if querySpec.IsListSeriesQuery() {
processor = engine.NewListSeriesEngine(response)
} else if querySpec.IsDeleteFromSeriesQuery() || querySpec.IsDropSeriesQuery() || querySpec.IsSinglePointQuery() {
maxDeleteResults := 10000
processor = engine.NewPassthroughEngine(response, maxDeleteResults)
} else {
query := querySpec.SelectQuery()
if self.ShouldAggregateLocally(querySpec) {
log.Debug("creating a query engine")
processor, err = engine.NewQueryEngine(query, response)
if err != nil {
response <- &p.Response{Type: &endStreamResponse, ErrorMessage: p.String(err.Error())}
log.Error("Error while creating engine: %s", err)
return
}
processor.SetShardInfo(int(self.Id()), self.IsLocal)
} else if query.HasAggregates() {
maxPointsToBufferBeforeSending := 1000
log.Debug("creating a passthrough engine")
processor = engine.NewPassthroughEngine(response, maxPointsToBufferBeforeSending)
} else {
maxPointsToBufferBeforeSending := 1000
log.Debug("creating a passthrough engine with limit")
processor = engine.NewPassthroughEngineWithLimit(response, maxPointsToBufferBeforeSending, query.Limit)
}
if query.GetFromClause().Type != parser.FromClauseInnerJoin {
// Joins do their own filtering since we need to get all
// points before filtering. This is due to the fact that some
// where expressions will be difficult to compute before the
// points are joined together, think where clause with
// left.column = 'something' or right.column =
// 'something_else'. We can't filter the individual series
// separately. The filtering happens in merge.go:55
processor = engine.NewFilteringEngine(query, processor)
}
}
shard, err := self.store.GetOrCreateShard(self.id)
if err != nil {
response <- &p.Response{Type: &endStreamResponse, ErrorMessage: p.String(err.Error())}
log.Error("Error while getting shards: %s", err)
return
}
defer self.store.ReturnShard(self.id)
err = shard.Query(querySpec, processor)
// if we call Close() in case of an error it will mask the error
if err != nil {
response <- &p.Response{Type: &endStreamResponse, ErrorMessage: p.String(err.Error())}
return
}
processor.Close()
response <- &p.Response{Type: &endStreamResponse}
return
}
if server := self.randomHealthyServer(); server != nil {
log.Debug("Querying server %d for shard %d", server.GetId(), self.Id())
request := self.createRequest(querySpec)
server.MakeRequest(request, response)
return
}
message := fmt.Sprintf("No servers up to query shard %d", self.id)
response <- &p.Response{Type: &endStreamResponse, ErrorMessage: &message}
log.Error(message)
}