diff --git a/internal/memorystore/api.go b/internal/memorystore/api.go
index 1f7a531..b96dc1f 100644
--- a/internal/memorystore/api.go
+++ b/internal/memorystore/api.go
@@ -6,12 +6,18 @@
 package memorystore
 
 import (
+	"errors"
 	"math"
 
 	"github.com/ClusterCockpit/cc-lib/schema"
 	"github.com/ClusterCockpit/cc-lib/util"
 )
 
+var (
+	ErrInvalidTimeRange = errors.New("[METRICSTORE]> invalid time range: 'from' must be before 'to'")
+	ErrEmptyCluster     = errors.New("[METRICSTORE]> cluster name cannot be empty")
+)
+
 type APIMetricData struct {
 	Error      *string           `json:"error,omitempty"`
 	Data       schema.FloatArray `json:"data,omitempty"`
@@ -109,10 +115,14 @@ func (data *APIMetricData) PadDataWithNull(ms *MemoryStore, from, to int64, metr
 }
 
 func FetchData(req APIQueryRequest) (*APIQueryResponse, error) {
-	req.WithData = true
-	req.WithData = true
-	req.WithData = true
+	if req.From > req.To {
+		return nil, ErrInvalidTimeRange
+	}
+	if req.Cluster == "" && req.ForAllNodes != nil {
+		return nil, ErrEmptyCluster
+	}
 
+	req.WithData = true
 	ms := GetMemoryStore()
 
 	response := APIQueryResponse{
diff --git a/internal/memorystore/archive.go b/internal/memorystore/archive.go
index 56065aa..5019ee7 100644
--- a/internal/memorystore/archive.go
+++ b/internal/memorystore/archive.go
@@ -32,17 +32,14 @@ func Archiving(wg *sync.WaitGroup, ctx context.Context) {
 			return
 		}
 
-		ticks := func() <-chan time.Time {
-			if d <= 0 {
-				return nil
-			}
-			return time.NewTicker(d).C
-		}()
+		ticker := time.NewTicker(d)
+		defer ticker.Stop()
+
 		for {
 			select {
 			case <-ctx.Done():
 				return
-			case <-ticks:
+			case <-ticker.C:
 				t := time.Now().Add(-d)
 				cclog.Infof("[METRICSTORE]> start archiving checkpoints (older than %s)...", t.Format(time.RFC3339))
 				n, err := ArchiveCheckpoints(Keys.Checkpoints.RootDir,
@@ -165,25 +162,33 @@ func archiveCheckpoints(dir string, archiveDir string, from int64, deleteInstead
 
 	n := 0
 	for _, checkpoint := range files {
-		filename := filepath.Join(dir, checkpoint)
-		r, err := os.Open(filename)
+		// Use closure to ensure file is closed immediately after use,
+		// avoiding file descriptor leak from defer in loop
+		err := func() error {
+			filename := filepath.Join(dir, checkpoint)
+			r, err := os.Open(filename)
+			if err != nil {
+				return err
+			}
+			defer r.Close()
+
+			w, err := zw.Create(checkpoint)
+			if err != nil {
+				return err
+			}
+
+			if _, err = io.Copy(w, r); err != nil {
+				return err
+			}
+
+			if err = os.Remove(filename); err != nil {
+				return err
+			}
+			return nil
+		}()
 		if err != nil {
 			return n, err
 		}
-		defer r.Close()
-
-		w, err := zw.Create(checkpoint)
-		if err != nil {
-			return n, err
-		}
-
-		if _, err = io.Copy(w, r); err != nil {
-			return n, err
-		}
-
-		if err = os.Remove(filename); err != nil {
-			return n, err
-		}
 		n += 1
 	}
 
diff --git a/internal/memorystore/avroCheckpoint.go b/internal/memorystore/avroCheckpoint.go
index 4d36151..42e5f62 100644
--- a/internal/memorystore/avroCheckpoint.go
+++ b/internal/memorystore/avroCheckpoint.go
@@ -24,9 +24,8 @@ import (
 	"github.com/linkedin/goavro/v2"
 )
 
-var NumAvroWorkers int = 4
+var NumAvroWorkers int = DefaultAvroWorkers
 var startUp bool = true
-var ErrNoNewData error = errors.New("no data in the pool")
 
 func (as *AvroStore) ToCheckpoint(dir string, dumpAll bool) (int, error) {
 	levels := make([]*AvroLevel, 0)
@@ -464,19 +463,15 @@ func generateRecord(data map[string]schema.Float) map[string]any {
 }
 
 func correctKey(key string) string {
-	// Replace any invalid characters in the key
-	// For example, replace spaces with underscores
-	key = strings.ReplaceAll(key, ":", "___")
-	key = strings.ReplaceAll(key, ".", "__")
-
+	key = strings.ReplaceAll(key, "_", "_0x5F_")
+	key = strings.ReplaceAll(key, ":", "_0x3A_")
+	key = strings.ReplaceAll(key, ".", "_0x2E_")
 	return key
 }
 
 func ReplaceKey(key string) string {
-	// Replace any invalid characters in the key
-	// For example, replace spaces with underscores
-	key = strings.ReplaceAll(key, "___", ":")
-	key = strings.ReplaceAll(key, "__", ".")
-
+	key = strings.ReplaceAll(key, "_0x2E_", ".")
+	key = strings.ReplaceAll(key, "_0x3A_", ":")
+	key = strings.ReplaceAll(key, "_0x5F_", "_")
 	return key
 }
diff --git a/internal/memorystore/avroHelper.go b/internal/memorystore/avroHelper.go
index 64e5706..a6f6c9b 100644
--- a/internal/memorystore/avroHelper.go
+++ b/internal/memorystore/avroHelper.go
@@ -42,7 +42,7 @@ func DataStaging(wg *sync.WaitGroup, ctx context.Context) {
 				metricName := ""
 
 				for _, selectorName := range val.Selector {
-					metricName += selectorName + Delimiter
+					metricName += selectorName + SelectorDelimiter
 				}
 
 				metricName += val.MetricName
@@ -54,7 +54,7 @@ func DataStaging(wg *sync.WaitGroup, ctx context.Context) {
 				var selector []string
 				selector = append(selector, val.Cluster, val.Node, strconv.FormatInt(freq, 10))
 
-				if !testEq(oldSelector, selector) {
+				if !stringSlicesEqual(oldSelector, selector) {
 					// Get the Avro level for the metric
 					avroLevel = avroStore.root.findAvroLevelOrCreate(selector)
 
@@ -71,7 +71,7 @@ func DataStaging(wg *sync.WaitGroup, ctx context.Context) {
 	}()
 }
 
-func testEq(a, b []string) bool {
+func stringSlicesEqual(a, b []string) bool {
 	if len(a) != len(b) {
 		return false
 	}
diff --git a/internal/memorystore/avroStruct.go b/internal/memorystore/avroStruct.go
index cc8005c..bde9e02 100644
--- a/internal/memorystore/avroStruct.go
+++ b/internal/memorystore/avroStruct.go
@@ -13,12 +13,11 @@ import (
 
 var (
 	LineProtocolMessages = make(chan *AvroStruct)
-	Delimiter            = "ZZZZZ"
+	// SelectorDelimiter separates hierarchical selector components in metric names for Avro encoding
+	SelectorDelimiter = "_SEL_"
 )
 
-// CheckpointBufferMinutes should always be in minutes.
-// Its controls the amount of data to hold for given amount of time.
-var CheckpointBufferMinutes = 3
+var CheckpointBufferMinutes = DefaultCheckpointBufferMin
 
 type AvroStruct struct {
 	MetricName string
@@ -73,7 +72,7 @@ func (l *AvroLevel) findAvroLevelOrCreate(selector []string) *AvroLevel {
 		}
 	}
 
-	// The level does not exist, take write lock for unqiue access:
+	// The level does not exist, take write lock for unique access:
 	l.lock.Lock()
 	// While this thread waited for the write lock, another thread
 	// could have created the child node.
diff --git a/internal/memorystore/buffer.go b/internal/memorystore/buffer.go
index cd2fd8f..55be2ad 100644
--- a/internal/memorystore/buffer.go
+++ b/internal/memorystore/buffer.go
@@ -12,15 +12,12 @@ import (
 	"github.com/ClusterCockpit/cc-lib/schema"
 )
 
-// Default buffer capacity.
-// `buffer.data` will only ever grow up to it's capacity and a new link
+// BufferCap is the default buffer capacity.
+// buffer.data will only ever grow up to its capacity and a new link
 // in the buffer chain will be created if needed so that no copying
 // of data or reallocation needs to happen on writes.
-const (
-	BufferCap int = 512
-)
+const BufferCap int = DefaultBufferCapacity
 
-// So that we can reuse allocations
 var bufferPool sync.Pool = sync.Pool{
 	New: func() any {
 		return &buffer{
@@ -75,7 +72,6 @@ func (b *buffer) write(ts int64, value schema.Float) (*buffer, error) {
 		newbuf := newBuffer(ts, b.frequency)
 		newbuf.prev = b
 		b.next = newbuf
-		b.close()
 		b = newbuf
 		idx = 0
 	}
@@ -103,8 +99,6 @@ func (b *buffer) firstWrite() int64 {
 	return b.start + (b.frequency / 2)
 }
 
-func (b *buffer) close() {}
-
 // Return all known values from `from` to `to`. Gaps of information are represented as NaN.
 // Simple linear interpolation is done between the two neighboring cells if possible.
 // If values at the start or end are missing, instead of NaN values, the second and thrid
@@ -139,8 +133,6 @@ func (b *buffer) read(from, to int64, data []schema.Float) ([]schema.Float, int6
 			data[i] += schema.NaN
 		} else if t < b.start {
 			data[i] += schema.NaN
-			// } else if b.data[idx].IsNaN() {
-			// 	data[i] += interpolate(idx, b.data)
 		} else {
 			data[i] += b.data[idx]
 		}
diff --git a/internal/memorystore/checkpoint.go b/internal/memorystore/checkpoint.go
index e19cbf7..c676977 100644
--- a/internal/memorystore/checkpoint.go
+++ b/internal/memorystore/checkpoint.go
@@ -28,15 +28,10 @@ import (
 	"github.com/linkedin/goavro/v2"
 )
 
-// File operation constants
 const (
-	// CheckpointFilePerms defines default permissions for checkpoint files
 	CheckpointFilePerms = 0o644
-	// CheckpointDirPerms defines default permissions for checkpoint directories
-	CheckpointDirPerms = 0o755
-	// GCTriggerInterval determines how often GC is forced during checkpoint loading
-	// GC is triggered every GCTriggerInterval*NumWorkers loaded hosts
-	GCTriggerInterval = 100
+	CheckpointDirPerms  = 0o755
+	GCTriggerInterval   = DefaultGCTriggerInterval
 )
 
 // Whenever changed, update MarshalJSON as well!
@@ -71,17 +66,14 @@ func Checkpointing(wg *sync.WaitGroup, ctx context.Context) {
 				return
 			}
 
-			ticks := func() <-chan time.Time {
-				if d <= 0 {
-					return nil
-				}
-				return time.NewTicker(d).C
-			}()
+			ticker := time.NewTicker(d)
+			defer ticker.Stop()
+
 			for {
 				select {
 				case <-ctx.Done():
 					return
-				case <-ticks:
+				case <-ticker.C:
 					cclog.Infof("[METRICSTORE]> start checkpointing (starting at %s)...", lastCheckpoint.Format(time.RFC3339))
 					now := time.Now()
 					n, err := ms.ToCheckpoint(Keys.Checkpoints.RootDir,
@@ -98,33 +90,23 @@ func Checkpointing(wg *sync.WaitGroup, ctx context.Context) {
 	} else {
 		go func() {
 			defer wg.Done()
-			d, _ := time.ParseDuration("1m")
 
 			select {
 			case <-ctx.Done():
 				return
 			case <-time.After(time.Duration(CheckpointBufferMinutes) * time.Minute):
-				// This is the first tick untill we collect the data for given minutes.
 				GetAvroStore().ToCheckpoint(Keys.Checkpoints.RootDir, false)
-				// log.Printf("Checkpointing %d avro files", count)
-
 			}
 
-			ticks := func() <-chan time.Time {
-				if d <= 0 {
-					return nil
-				}
-				return time.NewTicker(d).C
-			}()
+			ticker := time.NewTicker(DefaultAvroCheckpointInterval)
+			defer ticker.Stop()
 
 			for {
 				select {
 				case <-ctx.Done():
 					return
-				case <-ticks:
-					// Regular ticks of 1 minute to write data.
+				case <-ticker.C:
 					GetAvroStore().ToCheckpoint(Keys.Checkpoints.RootDir, false)
-					// log.Printf("Checkpointing %d avro files", count)
 				}
 			}
 		}()
@@ -329,7 +311,7 @@ func (m *MemoryStore) FromCheckpoint(dir string, from int64, extension string) (
 				lvl := m.root.findLevelOrCreate(host[:], len(m.Metrics))
 				nn, err := lvl.fromCheckpoint(m, filepath.Join(dir, host[0], host[1]), from, extension)
 				if err != nil {
-					cclog.Fatalf("[METRICSTORE]> error while loading checkpoints: %s", err.Error())
+					cclog.Errorf("[METRICSTORE]> error while loading checkpoints for %s/%s: %s", host[0], host[1], err.Error())
 					atomic.AddInt32(&errs, 1)
 				}
 				atomic.AddInt32(&n, int32(nn))
@@ -506,8 +488,8 @@ func (l *Level) loadAvroFile(m *MemoryStore, f *os.File, from int64) error {
 	for key, floatArray := range metricsData {
 		metricName := ReplaceKey(key)
 
-		if strings.Contains(metricName, Delimiter) {
-			subString := strings.Split(metricName, Delimiter)
+		if strings.Contains(metricName, SelectorDelimiter) {
+			subString := strings.Split(metricName, SelectorDelimiter)
 
 			lvl := l
 
@@ -557,12 +539,10 @@ func (l *Level) createBuffer(m *MemoryStore, metricName string, floatArray schem
 		next:      nil,
 		archived:  true,
 	}
-	b.close()
 
 	minfo, ok := m.Metrics[metricName]
 	if !ok {
 		return nil
-		// return errors.New("Unkown metric: " + name)
 	}
 
 	prev := l.metrics[minfo.offset]
@@ -616,17 +596,15 @@ func (l *Level) loadFile(cf *CheckpointFile, m *MemoryStore) error {
 		b := &buffer{
 			frequency: metric.Frequency,
 			start:     metric.Start,
-			data:      metric.Data[0:n:n], // Space is wasted here :(
+			data:      metric.Data[0:n:n],
 			prev:      nil,
 			next:      nil,
 			archived:  true,
 		}
-		b.close()
 
 		minfo, ok := m.Metrics[name]
 		if !ok {
 			continue
-			// return errors.New("Unkown metric: " + name)
 		}
 
 		prev := l.metrics[minfo.offset]
diff --git a/internal/memorystore/config.go b/internal/memorystore/config.go
index 8196ed6..fbd6234 100644
--- a/internal/memorystore/config.go
+++ b/internal/memorystore/config.go
@@ -7,6 +7,16 @@ package memorystore
 
 import (
 	"fmt"
+	"time"
+)
+
+const (
+	DefaultMaxWorkers             = 10
+	DefaultBufferCapacity         = 512
+	DefaultGCTriggerInterval      = 100
+	DefaultAvroWorkers            = 4
+	DefaultCheckpointBufferMin    = 3
+	DefaultAvroCheckpointInterval = time.Minute
 )
 
 var InternalCCMSFlag bool = false
@@ -14,7 +24,7 @@ var InternalCCMSFlag bool = false
 type MetricStoreConfig struct {
 	// Number of concurrent workers for checkpoint and archive operations.
 	// If not set or 0, defaults to min(runtime.NumCPU()/2+1, 10)
-	NumWorkers int `json:"num-workers"`
+	NumWorkers  int `json:"num-workers"`
 	Checkpoints struct {
 		FileFormat string `json:"file-format"`
 		Interval   string `json:"interval"`
@@ -31,20 +41,6 @@ type MetricStoreConfig struct {
 		RootDir       string `json:"directory"`
 		DeleteInstead bool   `json:"delete-instead"`
 	} `json:"archive"`
-	Nats []*NatsConfig `json:"nats"`
-}
-
-type NatsConfig struct {
-	// Address of the nats server
-	Address string `json:"address"`
-
-	// Username/Password, optional
-	Username string `json:"username"`
-	Password string `json:"password"`
-
-	// Creds file path
-	Credsfilepath string `json:"creds-file-path"`
-
 	Subscriptions []struct {
 		// Channel name
 		SubscribeTo string `json:"subscribe-to"`
diff --git a/internal/memorystore/level.go b/internal/memorystore/level.go
index aaa1210..f3b3d3f 100644
--- a/internal/memorystore/level.go
+++ b/internal/memorystore/level.go
@@ -46,7 +46,7 @@ func (l *Level) findLevelOrCreate(selector []string, nMetrics int) *Level {
 		}
 	}
 
-	// The level does not exist, take write lock for unqiue access:
+	// The level does not exist, take write lock for unique access:
 	l.lock.Lock()
 	// While this thread waited for the write lock, another thread
 	// could have created the child node.
diff --git a/internal/memorystore/lineprotocol.go b/internal/memorystore/lineprotocol.go
index 2bbd7ee..87d3b9e 100644
--- a/internal/memorystore/lineprotocol.go
+++ b/internal/memorystore/lineprotocol.go
@@ -11,113 +11,31 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ClusterCockpit/cc-backend/pkg/nats"
 	cclog "github.com/ClusterCockpit/cc-lib/ccLogger"
 	"github.com/ClusterCockpit/cc-lib/schema"
 	"github.com/influxdata/line-protocol/v2/lineprotocol"
-	"github.com/nats-io/nats.go"
 )
 
-// Each connection is handled in it's own goroutine. This is a blocking function.
-// func ReceiveRaw(ctx context.Context,
-// 	listener net.Listener,
-// 	handleLine func(*lineprotocol.Decoder, string) error,
-// ) error {
-// 	var wg sync.WaitGroup
-
-// 	wg.Add(1)
-// 	go func() {
-// 		defer wg.Done()
-// 		<-ctx.Done()
-// 		if err := listener.Close(); err != nil {
-// 			log.Printf("listener.Close(): %s", err.Error())
-// 		}
-// 	}()
-
-// 	for {
-// 		conn, err := listener.Accept()
-// 		if err != nil {
-// 			if errors.Is(err, net.ErrClosed) {
-// 				break
-// 			}
-
-// 			log.Printf("listener.Accept(): %s", err.Error())
-// 		}
-
-// 		wg.Add(2)
-// 		go func() {
-// 			defer wg.Done()
-// 			defer conn.Close()
-
-// 			dec := lineprotocol.NewDecoder(conn)
-// 			connctx, cancel := context.WithCancel(context.Background())
-// 			defer cancel()
-// 			go func() {
-// 				defer wg.Done()
-// 				select {
-// 				case <-connctx.Done():
-// 					conn.Close()
-// 				case <-ctx.Done():
-// 					conn.Close()
-// 				}
-// 			}()
-
-// 			if err := handleLine(dec, "default"); err != nil {
-// 				if errors.Is(err, net.ErrClosed) {
-// 					return
-// 				}
-
-// 				log.Printf("%s: %s", conn.RemoteAddr().String(), err.Error())
-// 				errmsg := make([]byte, 128)
-// 				errmsg = append(errmsg, `error: `...)
-// 				errmsg = append(errmsg, err.Error()...)
-// 				errmsg = append(errmsg, '\n')
-// 				conn.Write(errmsg)
-// 			}
-// 		}()
-// 	}
-
-// 	wg.Wait()
-// 	return nil
-// }
-
-// ReceiveNats connects to a nats server and subscribes to "updates". This is a
-// blocking function. handleLine will be called for each line recieved via
-// nats. Send `true` through the done channel for gracefull termination.
-func ReceiveNats(conf *(NatsConfig),
-	ms *MemoryStore,
+func ReceiveNats(ms *MemoryStore,
 	workers int,
 	ctx context.Context,
 ) error {
-	var opts []nats.Option
-	if conf.Username != "" && conf.Password != "" {
-		opts = append(opts, nats.UserInfo(conf.Username, conf.Password))
-	}
-
-	if conf.Credsfilepath != "" {
-		opts = append(opts, nats.UserCredentials(conf.Credsfilepath))
-	}
-
-	nc, err := nats.Connect(conf.Address, opts...)
-	if err != nil {
-		return err
-	}
-	defer nc.Close()
+	nc := nats.GetClient()
 
 	var wg sync.WaitGroup
-	var subs []*nats.Subscription
 
-	msgs := make(chan *nats.Msg, workers*2)
+	msgs := make(chan []byte, workers*2)
 
-	for _, sc := range conf.Subscriptions {
+	for _, sc := range Keys.Subscriptions {
 		clusterTag := sc.ClusterTag
-		var sub *nats.Subscription
 		if workers > 1 {
 			wg.Add(workers)
 
 			for range workers {
 				go func() {
 					for m := range msgs {
-						dec := lineprotocol.NewDecoderWithBytes(m.Data)
+						dec := lineprotocol.NewDecoderWithBytes(m)
 						if err := DecodeLine(dec, ms, clusterTag); err != nil {
 							cclog.Errorf("error: %s", err.Error())
 						}
@@ -127,37 +45,24 @@ func ReceiveNats(conf *(NatsConfig),
 				}()
 			}
 
-			sub, err = nc.Subscribe(sc.SubscribeTo, func(m *nats.Msg) {
-				msgs <- m
+			nc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {
+				msgs <- data
 			})
 		} else {
-			sub, err = nc.Subscribe(sc.SubscribeTo, func(m *nats.Msg) {
-				dec := lineprotocol.NewDecoderWithBytes(m.Data)
+			nc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {
+				dec := lineprotocol.NewDecoderWithBytes(data)
 				if err := DecodeLine(dec, ms, clusterTag); err != nil {
 					cclog.Errorf("error: %s", err.Error())
 				}
 			})
 		}
-
-		if err != nil {
-			return err
-		}
-		cclog.Infof("NATS subscription to '%s' on '%s' established", sc.SubscribeTo, conf.Address)
-		subs = append(subs, sub)
+		cclog.Infof("NATS subscription to '%s' established", sc.SubscribeTo)
 	}
 
 	<-ctx.Done()
-	for _, sub := range subs {
-		err = sub.Unsubscribe()
-		if err != nil {
-			cclog.Errorf("NATS unsubscribe failed: %s", err.Error())
-		}
-	}
 	close(msgs)
 	wg.Wait()
 
-	nc.Close()
-	cclog.Print("NATS connection closed")
 	return nil
 }
 
@@ -266,8 +171,6 @@ func DecodeLine(dec *lineprotocol.Decoder,
 			case "stype-id":
 				subTypeBuf = append(subTypeBuf, val...)
 			default:
-				// Ignore unkown tags (cc-metric-collector might send us a unit for example that we do not need)
-				// return fmt.Errorf("unkown tag: '%s' (value: '%s')", string(key), string(val))
 			}
 		}
 
diff --git a/internal/memorystore/memorystore.go b/internal/memorystore/memorystore.go
index 3e372f3..259a86e 100644
--- a/internal/memorystore/memorystore.go
+++ b/internal/memorystore/memorystore.go
@@ -44,8 +44,6 @@ var (
 	shutdownFunc context.CancelFunc
 )
 
-
-
 type Metric struct {
 	Name         string
 	Value        schema.Float
@@ -71,8 +69,7 @@ func Init(rawConfig json.RawMessage, wg *sync.WaitGroup) {
 
 	// Set NumWorkers from config or use default
 	if Keys.NumWorkers <= 0 {
-		maxWorkers := 10
-		Keys.NumWorkers = min(runtime.NumCPU()/2+1, maxWorkers)
+		Keys.NumWorkers = min(runtime.NumCPU()/2+1, DefaultMaxWorkers)
 	}
 	cclog.Debugf("[METRICSTORE]> Using %d workers for checkpoint/archive operations\n", Keys.NumWorkers)
 
@@ -144,20 +141,9 @@ func Init(rawConfig json.RawMessage, wg *sync.WaitGroup) {
 	// Store the shutdown function for later use by Shutdown()
 	shutdownFunc = shutdown
 
-	if Keys.Nats != nil {
-		for _, natsConf := range Keys.Nats {
-			// TODO: When multiple nats configs share a URL, do a single connect.
-			wg.Add(1)
-			nc := natsConf
-			go func() {
-				// err := ReceiveNats(conf.Nats, decodeLine, runtime.NumCPU()-1, ctx)
-				err := ReceiveNats(nc, ms, 1, ctx)
-				if err != nil {
-					cclog.Fatal(err)
-				}
-				wg.Done()
-			}()
-		}
+	err = ReceiveNats(ms, 1, ctx)
+	if err != nil {
+		cclog.Fatal(err)
 	}
 }
 
@@ -244,18 +230,18 @@ func Retention(wg *sync.WaitGroup, ctx context.Context) {
 			return
 		}
 
-		ticks := func() <-chan time.Time {
-			d := d / 2
-			if d <= 0 {
-				return nil
-			}
-			return time.NewTicker(d).C
-		}()
+		tickInterval := d / 2
+		if tickInterval <= 0 {
+			return
+		}
+		ticker := time.NewTicker(tickInterval)
+		defer ticker.Stop()
+
 		for {
 			select {
 			case <-ctx.Done():
 				return
-			case <-ticks:
+			case <-ticker.C:
 				t := time.Now().Add(-d)
 				cclog.Infof("[METRICSTORE]> start freeing buffers (older than %s)...\n", t.Format(time.RFC3339))
 				freed, err := ms.Free(nil, t.Unix())
@@ -332,7 +318,7 @@ func (m *MemoryStore) Read(selector util.Selector, metric string, from, to, reso
 
 	minfo, ok := m.Metrics[metric]
 	if !ok {
-		return nil, 0, 0, 0, errors.New("[METRICSTORE]> unkown metric: " + metric)
+		return nil, 0, 0, 0, errors.New("[METRICSTORE]> unknown metric: " + metric)
 	}
 
 	n, data := 0, make([]schema.Float, (to-from)/minfo.Frequency+1)
diff --git a/internal/memorystore/stats.go b/internal/memorystore/stats.go
index 91b1f2c..b2cb539 100644
--- a/internal/memorystore/stats.go
+++ b/internal/memorystore/stats.go
@@ -77,7 +77,7 @@ func (m *MemoryStore) Stats(selector util.Selector, metric string, from, to int6
 
 	minfo, ok := m.Metrics[metric]
 	if !ok {
-		return nil, 0, 0, errors.New("unkown metric: " + metric)
+		return nil, 0, 0, errors.New("unknown metric: " + metric)
 	}
 
 	n, samples := 0, 0