Log information about index version during startup

tsdb/shard.go

@@ -366,18 +366,21 @@ func (s *Shard) close() error {
 	return err
 }
 
+// IndexType returns the index version being used for this shard.
+//
+// IndexType returns the empty string if it is called before the shard is opened,
+// since it is only that point that the underlying index type is known.
 func (s *Shard) IndexType() string {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
-	if err := s.ready(); err != nil {
+	if s._engine == nil || s.index == nil { // Shard not open yet.
 		return ""
 	}
-
 	return s.index.Type()
 }
 
 // ready determines if the Shard is ready for queries or writes.
-// It returns nil if ready, otherwise ErrShardClosed or ErrShardDiabled
+// It returns nil if ready, otherwise ErrShardClosed or ErrShardDisabled
 func (s *Shard) ready() error {
 	var err error
 	if s._engine == nil {

tsdb/store.go

@@ -23,6 +23,7 @@ import (
 	"github.com/influxdata/influxdb/query"
 	"github.com/influxdata/influxql"
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 )
 
 var (
@@ -322,12 +323,16 @@ func (s *Store) loadShards() error {
 					}
 
 					resC <- &res{s: shard}
-					log.Info("Opened shard", zap.String("path", path), zap.Duration("duration", time.Since(start)))
+					log.Info("Opened shard", zap.String("index_version", shard.IndexType()), zap.String("path", path), zap.Duration("duration", time.Since(start)))
 				}(db.Name(), rp.Name(), sh.Name())
 			}
 		}
 	}
 
+	// indexVersions tracks counts of the number of different types of index
+	// being used within each database.
+	indexVersions := make(map[string]map[string]int)
+
 	// Gather results of opening shards concurrently, keeping track of how
 	// many databases we are managing.
 	for i := 0; i < n; i++ {
@@ -337,9 +342,25 @@ func (s *Store) loadShards() error {
 		}
 		s.shards[res.s.id] = res.s
 		s.databases[res.s.database] = struct{}{}
+
+		if _, ok := indexVersions[res.s.database]; !ok {
+			indexVersions[res.s.database] = make(map[string]int, 2)
+		}
+		indexVersions[res.s.database][res.s.IndexType()]++
 	}
 	close(resC)
 
+	// Check if any databases are running multiple index types.
+	for db, idxVersions := range indexVersions {
+		if len(idxVersions) > 1 {
+			var fields []zapcore.Field
+			for idx, cnt := range idxVersions {
+				fields = append(fields, zap.Int(fmt.Sprintf("%s_count", idx), cnt))
+			}
+			s.Logger.Warn("Mixed shard index types", append(fields, logger.Database(db))...)
+		}
+	}
+
 	// Enable all shards
 	for _, sh := range s.shards {
 		sh.SetEnabled(true)