fix #2733: hook CQs back in

client/influxdb.go

@@ -135,7 +135,7 @@ func (c *Client) Write(bp BatchPoints) (*Response, error) {
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Content-Type", "")
 	req.Header.Set("User-Agent", c.userAgent)
 	if c.username != "" {
 		req.SetBasicAuth(c.username, c.password)

cmd/influxd/run/server.go

@@ -8,6 +8,7 @@ import (
 	"github.com/influxdb/influxdb/meta"
 	"github.com/influxdb/influxdb/services/admin"
 	"github.com/influxdb/influxdb/services/collectd"
+	"github.com/influxdb/influxdb/services/continuous_querier"
 	"github.com/influxdb/influxdb/services/graphite"
 	"github.com/influxdb/influxdb/services/httpd"
 	"github.com/influxdb/influxdb/services/opentsdb"
@@ -57,6 +58,7 @@ func NewServer(c *Config, joinURLs string) *Server {
 	s.appendCollectdService(c.Collectd)
 	s.appendOpenTSDBService(c.OpenTSDB)
 	s.appendUDPService(c.UDP)
+	s.appendContinuousQueryService(c.ContinuousQuery)
 	for _, g := range c.Graphites {
 		s.appendGraphiteService(g)
 	}
@@ -116,6 +118,13 @@ func (s *Server) appendUDPService(c udp.Config) {
 	}
 	srv := udp.NewService(c)
 	srv.Server.PointsWriter = s.PointsWriter
+}
+
+func (s *Server) appendContinuousQueryService(c continuous_querier.Config) {
+	srv := continuous_querier.NewService(c)
+	srv.MetaStore = s.MetaStore
+	srv.QueryExecutor = s.QueryExecutor
+	srv.PointsWriter = s.PointsWriter
 	s.Services = append(s.Services, srv)
 }
 

meta/store.go

@@ -241,6 +241,11 @@ func (s *Store) createLocalNode() error {
 	return nil
 }
 
+// IsLeader returns true if this node is currently the leader.
+func (s *Store) IsLeader() bool {
+	return s.raft.VerifyLeader().Error() == nil
+}
+
 // LeaderCh returns a channel that notifies on leadership change.
 // Panics when the store has not been opened yet.
 func (s *Store) LeaderCh() <-chan bool {

services/continuous_querier/service.go

@@ -1 +1,343 @@
 package continuous_querier
+
+import (
+	"errors"
+	"log"
+	"os"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/influxdb/influxdb/cluster"
+	"github.com/influxdb/influxdb/influxql"
+	"github.com/influxdb/influxdb/meta"
+	"github.com/influxdb/influxdb/tsdb"
+)
+
+const (
+	// When planning a select statement, passing zero tells it not to chunk results. Only applies to raw queries
+	NoChunkingSize = 0
+)
+
+// Service manages continuous query execution.
+type Service struct {
+	MetaStore     *meta.Store
+	QueryExecutor *tsdb.QueryExecutor
+	PointsWriter  *cluster.PointsWriter
+	Config        *Config
+	RunInterval   time.Duration
+	Logger        *log.Logger
+	// lastRuns maps CQ name to last time it was run.
+	lastRuns map[string]time.Time
+	stop     chan struct{}
+	wg       *sync.WaitGroup
+}
+
+// NewService returns a new instance of Service.
+func NewService(c Config) *Service {
+	s := &Service{
+		Config:      &c,
+		RunInterval: time.Second,
+		Logger:      log.New(os.Stderr, "[continuous_querier] ", log.LstdFlags),
+		lastRuns:    map[string]time.Time{},
+	}
+	return s
+}
+
+// Open starts the service.
+func (s *Service) Open() error {
+	if s.stop != nil {
+		return nil
+	}
+
+	if s.MetaStore == nil {
+		panic("MetaStore is nil")
+	} else if s.QueryExecutor == nil {
+		panic("QueryExecutor is nil")
+	} else if s.PointsWriter == nil {
+		panic("PointsWriter is nil")
+	}
+
+	s.stop = make(chan struct{})
+	s.wg = &sync.WaitGroup{}
+	s.wg.Add(1)
+	go s.backgroundLoop()
+	return nil
+}
+
+// Close stops the service.
+func (s *Service) Close() error {
+	if s.stop == nil {
+		return nil
+	}
+	close(s.stop)
+	s.wg.Wait()
+	s.wg = nil
+	s.stop = nil
+	return nil
+}
+
+// backgroundLoop runs on a go routine and periodically executes CQs.
+func (s *Service) backgroundLoop() {
+	defer s.wg.Done()
+	for {
+		select {
+		case <-s.stop:
+			return
+		case <-time.After(s.RunInterval):
+			if s.MetaStore.IsLeader() {
+				s.runContinuousQueries()
+			}
+		}
+	}
+}
+
+// runContinuousQueries gets CQs from the meta store and runs them.
+func (s *Service) runContinuousQueries() {
+	// Get list of all databases.
+	dbs, err := s.MetaStore.Databases()
+	if err != nil {
+		s.Logger.Println("error getting databases")
+		return
+	}
+	// Loop through all databases executing CQs.
+	for _, db := range dbs {
+		// TODO: distribute across nodes
+		for _, cq := range db.ContinuousQueries {
+			if err := s.ExecuteContinuousQuery(&db, &cq); err != nil {
+				s.Logger.Println(err)
+			}
+		}
+	}
+}
+
+// ExecuteContinuousQuery executes a single CQ.
+func (s *Service) ExecuteContinuousQuery(dbi *meta.DatabaseInfo, cqi *meta.ContinuousQueryInfo) error {
+	// TODO: re-enable stats
+	//s.stats.Inc("continuousQueryExecuted")
+
+	// Local wrapper / helper.
+	cq, err := NewContinuousQuery(dbi.Name, cqi)
+	if err != nil {
+		return err
+	}
+
+	// Get the last time this CQ was run from the service's cache.
+	cq.LastRun = s.lastRuns[cqi.Name]
+
+	// Set the retention policy to default if it wasn't specified in the query.
+	if cq.intoRP() == "" {
+		cq.setIntoRP(dbi.DefaultRetentionPolicy)
+	}
+
+	// See if this query needs to be run.
+	computeNoMoreThan := time.Duration(s.Config.ComputeNoMoreThan)
+	if !cq.shouldRunContinuousQuery(s.Config.ComputeRunsPerInterval, computeNoMoreThan) {
+		return nil
+	}
+
+	// We're about to run the query so store the time.
+	now := time.Now()
+	cq.LastRun = now
+	s.lastRuns[cqi.Name] = now
+
+	// Get the group by interval.
+	interval, err := cq.q.GroupByInterval()
+	if err != nil || interval == 0 {
+		return nil
+	}
+
+	// Calculate and set the time range for the query.
+	startTime := now.Round(interval)
+	if startTime.UnixNano() > now.UnixNano() {
+		startTime = startTime.Add(-interval)
+	}
+
+	if err := cq.q.SetTimeRange(startTime, startTime.Add(interval)); err != nil {
+		s.Logger.Printf("error setting time range: %s\n", err)
+	}
+
+	// Do the actual processing of the query & writing of results.
+	if err := s.runContinuousQueryAndWriteResult(cq); err != nil {
+		s.Logger.Printf("error: %s. running: %s\n", err, cq.q.String())
+	}
+
+	recomputeNoOlderThan := time.Duration(s.Config.RecomputeNoOlderThan)
+
+	for i := 0; i < s.Config.RecomputePreviousN; i++ {
+		// if we're already more time past the previous window than we're going to look back, stop
+		if now.Sub(startTime) > recomputeNoOlderThan {
+			return nil
+		}
+		newStartTime := startTime.Add(-interval)
+
+		if err := cq.q.SetTimeRange(newStartTime, startTime); err != nil {
+			s.Logger.Printf("error setting time range: %s\n", err)
+		}
+
+		if err := s.runContinuousQueryAndWriteResult(cq); err != nil {
+			s.Logger.Printf("error during recompute previous: %s. running: %s\n", err, cq.q.String())
+		}
+
+		startTime = newStartTime
+	}
+	return nil
+}
+
+// runContinuousQueryAndWriteResult will run the query against the cluster and write the results back in
+func (s *Service) runContinuousQueryAndWriteResult(cq *ContinuousQuery) error {
+	// Wrap the CQ's inner SELECT statement in a Query for the QueryExecutor.
+	q := &influxql.Query{
+		Statements: influxql.Statements{cq.q},
+	}
+
+	// Execute the SELECT.
+	ch, err := s.QueryExecutor.ExecuteQuery(q, cq.Database, NoChunkingSize)
+	if err != nil {
+		return err
+	}
+
+	// Read all rows from the result channel.
+	for result := range ch {
+		if result.Err != nil {
+			return result.Err
+		}
+
+		for _, row := range result.Series {
+			// Convert the result row to points.
+			points, err := s.convertRowToPoints(cq.intoMeasurement(), row)
+			if err != nil {
+				log.Println(err)
+				continue
+			}
+
+			if len(points) == 0 {
+				continue
+			}
+
+			// If the points have any nil values, can't write.
+			// This happens if the CQ is created and running before data is written to the measurement.
+			for _, p := range points {
+				fields := p.Fields()
+				for _, v := range fields {
+					if v == nil {
+						return nil
+					}
+				}
+			}
+
+			// Create a write request for the points.
+			req := &cluster.WritePointsRequest{
+				Database:         cq.intoDB(),
+				RetentionPolicy:  cq.intoRP(),
+				ConsistencyLevel: cluster.ConsistencyLevelAny,
+				Points:           points,
+			}
+
+			// Write the request.
+			if err := s.PointsWriter.WritePoints(req); err != nil {
+				s.Logger.Println(err)
+			}
+		}
+	}
+
+	return nil
+}
+
+// convertRowToPoints will convert a query result Row into Points that can be written back in.
+// Used for continuous and INTO queries
+func (s *Service) convertRowToPoints(measurementName string, row *influxql.Row) ([]tsdb.Point, error) {
+	// figure out which parts of the result are the time and which are the fields
+	timeIndex := -1
+	fieldIndexes := make(map[string]int)
+	for i, c := range row.Columns {
+		if c == "time" {
+			timeIndex = i
+		} else {
+			fieldIndexes[c] = i
+		}
+	}
+
+	if timeIndex == -1 {
+		return nil, errors.New("error finding time index in result")
+	}
+
+	points := make([]tsdb.Point, 0, len(row.Values))
+	for _, v := range row.Values {
+		vals := make(map[string]interface{})
+		for fieldName, fieldIndex := range fieldIndexes {
+			vals[fieldName] = v[fieldIndex]
+		}
+
+		p := tsdb.NewPoint(measurementName, row.Tags, vals, v[timeIndex].(time.Time))
+
+		points = append(points, p)
+	}
+
+	return points, nil
+}
+
+// ContinuousQuery is a local wrapper / helper around continuous queries.
+type ContinuousQuery struct {
+	Database string
+	Info     *meta.ContinuousQueryInfo
+	LastRun  time.Time
+	q        *influxql.SelectStatement
+}
+
+func (cq *ContinuousQuery) intoDB() string          { return cq.q.Target.Measurement.Database }
+func (cq *ContinuousQuery) intoRP() string          { return cq.q.Target.Measurement.RetentionPolicy }
+func (cq *ContinuousQuery) setIntoRP(rp string)     { cq.q.Target.Measurement.RetentionPolicy = rp }
+func (cq *ContinuousQuery) intoMeasurement() string { return cq.q.Target.Measurement.Name }
+
+// NewContinuousQuery returns a ContinuousQuery object with a parsed influxql.CreateContinuousQueryStatement
+func NewContinuousQuery(database string, cqi *meta.ContinuousQueryInfo) (*ContinuousQuery, error) {
+	stmt, err := influxql.NewParser(strings.NewReader(cqi.Query)).ParseStatement()
+	if err != nil {
+		return nil, err
+	}
+
+	q, ok := stmt.(*influxql.SelectStatement)
+	if !ok {
+		return nil, errors.New("query isn't a valid continuous query")
+	}
+
+	cquery := &ContinuousQuery{
+		Database: database,
+		Info:     cqi,
+		q:        q,
+	}
+
+	return cquery, nil
+}
+
+// shouldRunContinuousQuery returns true if the CQ should be schedule to run. It will use the
+// lastRunTime of the CQ and the rules for when to run set through the config to determine
+// if this CQ should be run
+func (cq *ContinuousQuery) shouldRunContinuousQuery(runsPerInterval int, noMoreThan time.Duration) bool {
+	// if it's not aggregated we don't run it
+	if cq.q.IsRawQuery {
+		return false
+	}
+
+	// since it's aggregated we need to figure how often it should be run
+	interval, err := cq.q.GroupByInterval()
+	if err != nil {
+		return false
+	}
+
+	// determine how often we should run this continuous query.
+	// group by time / the number of times to compute
+	computeEvery := time.Duration(interval.Nanoseconds()/int64(runsPerInterval)) * time.Nanosecond
+	// make sure we're running no more frequently than the setting in the config
+	if computeEvery < noMoreThan {
+		computeEvery = noMoreThan
+	}
+
+	// if we've passed the amount of time since the last run, do it up
+	if cq.LastRun.Add(computeEvery).UnixNano() <= time.Now().UnixNano() {
+		return true
+	}
+
+	return false
+}