diff --git a/.gitignore b/.gitignore
index 81accb2..e1cd189 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,3 +18,9 @@
 # Project specific ignores
 /var
 /configs
+
+sample.txt
+
+migrateTimestamps.pl
+test_ccms_api.sh
+test_ccms_free_api.sh
diff --git a/api/swagger.json b/api/swagger.json
index 402fd11..08522ca 100644
--- a/api/swagger.json
+++ b/api/swagger.json
@@ -75,7 +75,7 @@
             }
         },
         "/free/": {
-            "get": {
+            "post": {
                 "security": [
                     {
                         "ApiKeyAuth": []
@@ -273,6 +273,9 @@
                 "min": {
                     "type": "number"
                 },
+                "resolution": {
+                    "type": "integer"
+                },
                 "to": {
                     "type": "integer"
                 }
@@ -290,6 +293,9 @@
                 "metric": {
                     "type": "string"
                 },
+                "resolution": {
+                    "type": "integer"
+                },
                 "scale-by": {
                     "type": "number"
                 },
diff --git a/api/swagger.yaml b/api/swagger.yaml
index 51c7322..b14ba8a 100644
--- a/api/swagger.yaml
+++ b/api/swagger.yaml
@@ -16,6 +16,8 @@ definitions:
         type: number
       min:
         type: number
+      resolution:
+        type: integer
       to:
         type: integer
     type: object
@@ -27,6 +29,8 @@ definitions:
         type: string
       metric:
         type: string
+      resolution:
+        type: integer
       scale-by:
         type: number
       subtype:
@@ -137,7 +141,7 @@ paths:
       tags:
       - debug
   /free/:
-    get:
+    post:
       parameters:
       - description: up to timestamp
         in: query
diff --git a/config.json b/config.json
index 6bd9f84..23d8a10 100644
--- a/config.json
+++ b/config.json
@@ -1,45 +1,185 @@
 {
-  "metrics": {
-    "flops_any": {
-      "frequency": 15,
-      "aggregation": "sum"
+    "metrics": {
+        "debug_metric": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "clock": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "cpu_idle": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "cpu_iowait": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "cpu_irq": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "cpu_system": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "cpu_user": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "nv_mem_util": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "nv_temp": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "nv_sm_clock": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "acc_utilization": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "acc_mem_used": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "acc_power": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "flops_any": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "flops_dp": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "flops_sp": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "ib_recv": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "ib_xmit": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "ib_recv_pkts": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "ib_xmit_pkts": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "cpu_power": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "core_power": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "mem_power": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "ipc": {
+            "frequency": 60,
+            "aggregation": "avg"
+        },
+        "cpu_load": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "lustre_close": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "lustre_open": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "lustre_statfs": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "lustre_read_bytes": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "lustre_write_bytes": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "net_bw": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "file_bw": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "mem_bw": {
+            "frequency": 60,
+            "aggregation": "sum"
+        },
+        "mem_cached": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "mem_used": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "net_bytes_in": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "net_bytes_out": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "nfs4_read": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "nfs4_total": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "nfs4_write": {
+            "frequency": 60,
+            "aggregation": null
+        },
+        "vectorization_ratio": {
+            "frequency": 60,
+            "aggregation": "avg"
+        }
     },
-    "flops_dp": {
-      "frequency": 15,
-      "aggregation": "sum"
+    "checkpoints": {
+        "interval": "1h",
+        "directory": "./var/checkpoints",
+        "restore": "1h"
     },
-    "flops_sp": {
-      "frequency": 15,
-      "aggregation": "sum"
+    "archive": {
+        "interval": "2h",
+        "directory": "./var/archive"
     },
-    "mem_bw": {
-      "frequency": 15,
-      "aggregation": "sum"
+    "http-api": {
+        "address": "localhost:8082",
+        "https-cert-file": null,
+        "https-key-file": null
     },
-    "load_one": {
-      "frequency": 15,
-      "aggregation": null
-    },
-    "load_five": {
-      "frequency": 15,
-      "aggregation": null
-    }
-  },
-  "checkpoints": {
-    "interval": "12h",
-    "directory": "./var/checkpoints",
-    "restore": "48h"
-  },
-  "archive": {
-    "interval": "168h",
-    "directory": "./var/archive"
-  },
-  "http-api": {
-    "address": "127.0.0.1:8081",
-    "https-cert-file": null,
-    "https-key-file": null
-  },
-  "retention-in-memory": "48h",
-  "nats": null,
-  "jwt-public-key": "kzfYrYy+TzpanWZHJ5qSdMj5uKUWgq74BWhQG6copP0="
-}
+    "retention-in-memory": "1h",
+    "nats": null,
+    "jwt-public-key": "kzfYrYy+TzpanWZHJ5qSdMj5uKUWgq74BWhQG6copP0="
+}
\ No newline at end of file
diff --git a/internal/api/api.go b/internal/api/api.go
index b5e55fa..6e5968c 100644
--- a/internal/api/api.go
+++ b/internal/api/api.go
@@ -47,13 +47,14 @@ type ErrorResponse struct {
 }
 
 type ApiMetricData struct {
-	Error *string         `json:"error,omitempty"`
-	Data  util.FloatArray `json:"data,omitempty"`
-	From  int64           `json:"from"`
-	To    int64           `json:"to"`
-	Avg   util.Float      `json:"avg"`
-	Min   util.Float      `json:"min"`
-	Max   util.Float      `json:"max"`
+	Error      *string         `json:"error,omitempty"`
+	Data       util.FloatArray `json:"data,omitempty"`
+	From       int64           `json:"from"`
+	To         int64           `json:"to"`
+	Resolution int64           `json:"resolution"`
+	Avg        util.Float      `json:"avg"`
+	Min        util.Float      `json:"min"`
+	Max        util.Float      `json:"max"`
 }
 
 func handleError(err error, statusCode int, rw http.ResponseWriter) {
@@ -135,7 +136,7 @@ func (data *ApiMetricData) PadDataWithNull(ms *memorystore.MemoryStore, from, to
 // @failure     403            {object} api.ErrorResponse       "Forbidden"
 // @failure     500            {object} api.ErrorResponse       "Internal Server Error"
 // @security    ApiKeyAuth
-// @router      /free/ [get]
+// @router      /free/ [post]
 func handleFree(rw http.ResponseWriter, r *http.Request) {
 	rawTo := r.URL.Query().Get("to")
 	if rawTo == "" {
@@ -234,6 +235,7 @@ type ApiQuery struct {
 	SubType     *string    `json:"subtype,omitempty"`
 	Metric      string     `json:"metric"`
 	Hostname    string     `json:"host"`
+	Resolution  int64      `json:"resolution"`
 	TypeIds     []string   `json:"type-ids,omitempty"`
 	SubTypeIds  []string   `json:"subtype-ids,omitempty"`
 	ScaleFactor util.Float `json:"scale-by,omitempty"`
@@ -256,6 +258,10 @@ type ApiQuery struct {
 // @router      /query/ [get]
 func handleQuery(rw http.ResponseWriter, r *http.Request) {
 	var err error
+	ver := r.URL.Query().Get("version")
+	if ver == "" {
+		ver = "v2"
+	}
 	req := ApiQueryRequest{WithStats: true, WithData: true, WithPadding: true}
 	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
 		handleError(err, http.StatusBadRequest, rw)
@@ -336,8 +342,11 @@ func handleQuery(rw http.ResponseWriter, r *http.Request) {
 		res := make([]ApiMetricData, 0, len(sels))
 		for _, sel := range sels {
 			data := ApiMetricData{}
-			data.Data, data.From, data.To, err = ms.Read(sel, query.Metric, req.From, req.To)
-			// log.Printf("data: %#v, %#v, %#v, %#v", data.Data, data.From, data.To, err)
+			if ver == "v1" {
+				data.Data, data.From, data.To, data.Resolution, err = ms.Read(sel, query.Metric, req.From, req.To, 0)
+			} else {
+				data.Data, data.From, data.To, data.Resolution, err = ms.Read(sel, query.Metric, req.From, req.To, query.Resolution)
+			}
 			if err != nil {
 				msg := err.Error()
 				data.Error = &msg
diff --git a/internal/api/docs.go b/internal/api/docs.go
index 9d49c13..84cec70 100644
--- a/internal/api/docs.go
+++ b/internal/api/docs.go
@@ -81,7 +81,7 @@ const docTemplate = `{
             }
         },
         "/free/": {
-            "get": {
+            "post": {
                 "security": [
                     {
                         "ApiKeyAuth": []
@@ -279,6 +279,9 @@ const docTemplate = `{
                 "min": {
                     "type": "number"
                 },
+                "resolution": {
+                    "type": "integer"
+                },
                 "to": {
                     "type": "integer"
                 }
@@ -296,6 +299,9 @@ const docTemplate = `{
                 "metric": {
                     "type": "string"
                 },
+                "resolution": {
+                    "type": "integer"
+                },
                 "scale-by": {
                     "type": "number"
                 },
diff --git a/internal/api/lineprotocol.go b/internal/api/lineprotocol.go
index 9081638..f675a3a 100644
--- a/internal/api/lineprotocol.go
+++ b/internal/api/lineprotocol.go
@@ -255,7 +255,8 @@ func decodeLine(dec *lineprotocol.Decoder,
 				if len(subTypeBuf) == 0 {
 					subTypeBuf = append(subTypeBuf, val...)
 				} else {
-					subTypeBuf = reorder(typeBuf, val)
+					subTypeBuf = reorder(subTypeBuf, val)
+					// subTypeBuf = reorder(typeBuf, val)
 				}
 			case "stype-id":
 				subTypeBuf = append(subTypeBuf, val...)
@@ -308,7 +309,7 @@ func decodeLine(dec *lineprotocol.Decoder,
 		}
 
 		if t, err = dec.Time(lineprotocol.Second, t); err != nil {
-			return err
+			return fmt.Errorf("timestamp : %#v with error : %#v", lineprotocol.Second, err.Error())
 		}
 
 		if err := ms.WriteToLevel(lvl, selector, t.Unix(), []memorystore.Metric{metric}); err != nil {
diff --git a/internal/api/server.go b/internal/api/server.go
index 3f7bcd9..3b69c4c 100644
--- a/internal/api/server.go
+++ b/internal/api/server.go
@@ -20,11 +20,23 @@ func MountRoutes(r *http.ServeMux) {
 			log.Fatalf("starting server failed: %v", err)
 		}
 		publicKey := ed25519.PublicKey(buf)
+		// Compatibility
+		r.Handle("POST /api/free", authHandler(http.HandlerFunc(handleFree), publicKey))
+		r.Handle("POST /api/write", authHandler(http.HandlerFunc(handleWrite), publicKey))
+		r.Handle("GET /api/query", authHandler(http.HandlerFunc(handleQuery), publicKey))
+		r.Handle("GET /api/debug", authHandler(http.HandlerFunc(handleDebug), publicKey))
+		// Refactor
 		r.Handle("POST /api/free/", authHandler(http.HandlerFunc(handleFree), publicKey))
 		r.Handle("POST /api/write/", authHandler(http.HandlerFunc(handleWrite), publicKey))
 		r.Handle("GET /api/query/", authHandler(http.HandlerFunc(handleQuery), publicKey))
 		r.Handle("GET /api/debug/", authHandler(http.HandlerFunc(handleDebug), publicKey))
 	} else {
+		// Compatibility
+		r.HandleFunc("POST /api/free", handleFree)
+		r.HandleFunc("POST /api/write", handleWrite)
+		r.HandleFunc("GET /api/query", handleQuery)
+		r.HandleFunc("GET /api/debug", handleDebug)
+		// Refactor
 		r.HandleFunc("POST /api/free/", handleFree)
 		r.HandleFunc("POST /api/write/", handleWrite)
 		r.HandleFunc("GET /api/query/", handleQuery)
diff --git a/internal/memorystore/checkpoint.go b/internal/memorystore/checkpoint.go
index 9b036d5..93585b6 100644
--- a/internal/memorystore/checkpoint.go
+++ b/internal/memorystore/checkpoint.go
@@ -478,8 +478,10 @@ func findFiles(direntries []fs.DirEntry, t int64, findMoreRecentFiles bool) ([]s
 		e := direntries[i]
 		ts1 := nums[e.Name()]
 
-		if findMoreRecentFiles && t <= ts1 || i == len(direntries)-1 {
+		if findMoreRecentFiles && t <= ts1 {
 			filenames = append(filenames, e.Name())
+		}
+		if i == len(direntries)-1 {
 			continue
 		}
 
diff --git a/internal/memorystore/level.go b/internal/memorystore/level.go
index 4bbfe7c..f5f133a 100644
--- a/internal/memorystore/level.go
+++ b/internal/memorystore/level.go
@@ -107,6 +107,10 @@ func (l *Level) sizeInBytes() int64 {
 		}
 	}
 
+	for _, child := range l.children {
+		size += child.sizeInBytes()
+	}
+
 	return size
 }
 
diff --git a/internal/memorystore/memorystore.go b/internal/memorystore/memorystore.go
index 4868a85..229ab00 100644
--- a/internal/memorystore/memorystore.go
+++ b/internal/memorystore/memorystore.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/ClusterCockpit/cc-metric-store/internal/config"
 	"github.com/ClusterCockpit/cc-metric-store/internal/util"
+	"github.com/ClusterCockpit/cc-metric-store/pkg/resampler"
 )
 
 var (
@@ -178,17 +179,18 @@ func (m *MemoryStore) WriteToLevel(l *Level, selector []string, ts int64, metric
 // If the level does not hold the metric itself, the data will be aggregated recursively from the children.
 // The second and third return value are the actual from/to for the data. Those can be different from
 // the range asked for if no data was available.
-func (m *MemoryStore) Read(selector util.Selector, metric string, from, to int64) ([]util.Float, int64, int64, error) {
+func (m *MemoryStore) Read(selector util.Selector, metric string, from, to, resolution int64) ([]util.Float, int64, int64, int64, error) {
 	if from > to {
-		return nil, 0, 0, errors.New("invalid time range")
+		return nil, 0, 0, 0, errors.New("invalid time range")
 	}
 
 	minfo, ok := m.Metrics[metric]
 	if !ok {
-		return nil, 0, 0, errors.New("unkown metric: " + metric)
+		return nil, 0, 0, 0, errors.New("unkown metric: " + metric)
 	}
 
 	n, data := 0, make([]util.Float, (to-from)/minfo.Frequency+1)
+
 	err := m.root.findBuffers(selector, minfo.Offset, func(b *buffer) error {
 		cdata, cfrom, cto, err := b.read(from, to, data)
 		if err != nil {
@@ -221,9 +223,9 @@ func (m *MemoryStore) Read(selector util.Selector, metric string, from, to int64
 	})
 
 	if err != nil {
-		return nil, 0, 0, err
+		return nil, 0, 0, 0, err
 	} else if n == 0 {
-		return nil, 0, 0, errors.New("metric or host not found")
+		return nil, 0, 0, 0, errors.New("metric or host not found")
 	} else if n > 1 {
 		if minfo.Aggregation == config.AvgAggregation {
 			normalize := 1. / util.Float(n)
@@ -231,11 +233,17 @@ func (m *MemoryStore) Read(selector util.Selector, metric string, from, to int64
 				data[i] *= normalize
 			}
 		} else if minfo.Aggregation != config.SumAggregation {
-			return nil, 0, 0, errors.New("invalid aggregation")
+			return nil, 0, 0, 0, errors.New("invalid aggregation")
 		}
 	}
 
-	return data, from, to, nil
+	data, resolution, err = resampler.LargestTriangleThreeBucket(data, minfo.Frequency, resolution)
+
+	if err != nil {
+		return nil, 0, 0, 0, err
+	}
+
+	return data, from, to, resolution, nil
 }
 
 // Release all buffers for the selected level and all its children that contain only
diff --git a/pkg/resampler/resampler.go b/pkg/resampler/resampler.go
new file mode 100644
index 0000000..59288c5
--- /dev/null
+++ b/pkg/resampler/resampler.go
@@ -0,0 +1,122 @@
+package resampler
+
+import (
+	"errors"
+	"fmt"
+	"math"
+
+	"github.com/ClusterCockpit/cc-metric-store/internal/util"
+)
+
+func SimpleResampler(data []util.Float, old_frequency int64, new_frequency int64) ([]util.Float, error) {
+	if old_frequency == 0 || new_frequency == 0 {
+		return nil, errors.New("either old or new frequency is set to 0")
+	}
+
+	if new_frequency%old_frequency != 0 {
+		return nil, errors.New("new sampling frequency should be multiple of the old frequency")
+	}
+
+	var step int = int(new_frequency / old_frequency)
+	var new_data_length = len(data) / step
+
+	if new_data_length == 0 || len(data) < 100 || new_data_length >= len(data) {
+		return data, nil
+	}
+
+	new_data := make([]util.Float, new_data_length)
+
+	for i := 0; i < new_data_length; i++ {
+		new_data[i] = data[i*step]
+	}
+
+	return new_data, nil
+}
+
+// Inspired by one of the algorithms from https://skemman.is/bitstream/1946/15343/3/SS_MSthesis.pdf
+// Adapted from https://github.com/haoel/downsampling/blob/master/core/lttb.go
+func LargestTriangleThreeBucket(data []util.Float, old_frequency int64, new_frequency int64) ([]util.Float, int64, error) {
+
+	if old_frequency == 0 || new_frequency == 0 {
+		return data, old_frequency, nil
+	}
+
+	if new_frequency%old_frequency != 0 {
+		return nil, 0, fmt.Errorf("new sampling frequency : %d should be multiple of the old frequency : %d", new_frequency, old_frequency)
+	}
+
+	var step int = int(new_frequency / old_frequency)
+	var new_data_length = len(data) / step
+
+	if new_data_length == 0 || len(data) < 100 || new_data_length >= len(data) {
+		return data, old_frequency, nil
+	}
+
+	new_data := make([]util.Float, 0, new_data_length)
+
+	// Bucket size. Leave room for start and end data points
+	bucketSize := float64(len(data)-2) / float64(new_data_length-2)
+
+	new_data = append(new_data, data[0]) // Always add the first point
+
+	// We have 3 pointers represent for
+	// > bucketLow - the current bucket's beginning location
+	// > bucketMiddle - the current bucket's ending location,
+	//                  also the beginning location of next bucket
+	// > bucketHight - the next bucket's ending location.
+	bucketLow := 1
+	bucketMiddle := int(math.Floor(bucketSize)) + 1
+
+	var prevMaxAreaPoint int
+
+	for i := 0; i < new_data_length-2; i++ {
+
+		bucketHigh := int(math.Floor(float64(i+2)*bucketSize)) + 1
+		if bucketHigh >= len(data)-1 {
+			bucketHigh = len(data) - 2
+		}
+
+		// Calculate point average for next bucket (containing c)
+		avgPointX, avgPointY := calculateAverageDataPoint(data[bucketMiddle:bucketHigh+1], int64(bucketMiddle))
+
+		// Get the range for current bucket
+		currBucketStart := bucketLow
+		currBucketEnd := bucketMiddle
+
+		// Point a
+		pointX := prevMaxAreaPoint
+		pointY := data[prevMaxAreaPoint]
+
+		maxArea := -1.0
+
+		var maxAreaPoint int
+		flag_ := 0
+		for ; currBucketStart < currBucketEnd; currBucketStart++ {
+
+			area := calculateTriangleArea(util.Float(pointX), pointY, avgPointX, avgPointY, util.Float(currBucketStart), data[currBucketStart])
+			if area > maxArea {
+				maxArea = area
+				maxAreaPoint = currBucketStart
+			}
+			if math.IsNaN(float64(avgPointY)) {
+				flag_ = 1
+			}
+		}
+
+		if flag_ == 1 {
+			new_data = append(new_data, util.NaN) // Pick this point from the bucket
+
+		} else {
+			new_data = append(new_data, data[maxAreaPoint]) // Pick this point from the bucket
+		}
+		prevMaxAreaPoint = maxAreaPoint // This MaxArea point is the next's prevMAxAreaPoint
+
+		//move to the next window
+		bucketLow = bucketMiddle
+		bucketMiddle = bucketHigh
+	}
+
+	new_data = append(new_data, data[len(data)-1]) // Always add last
+
+	return new_data, new_frequency, nil
+}
diff --git a/pkg/resampler/util.go b/pkg/resampler/util.go
new file mode 100644
index 0000000..61397bf
--- /dev/null
+++ b/pkg/resampler/util.go
@@ -0,0 +1,35 @@
+package resampler
+
+import (
+	"math"
+
+	"github.com/ClusterCockpit/cc-metric-store/internal/util"
+)
+
+func calculateTriangleArea(paX, paY, pbX, pbY, pcX, pcY util.Float) float64 {
+	area := ((paX-pcX)*(pbY-paY) - (paX-pbX)*(pcY-paY)) * 0.5
+	return math.Abs(float64(area))
+}
+
+func calculateAverageDataPoint(points []util.Float, xStart int64) (avgX util.Float, avgY util.Float) {
+	flag := 0
+	for _, point := range points {
+		avgX += util.Float(xStart)
+		avgY += point
+		xStart++
+		if math.IsNaN(float64(point)) {
+			flag = 1
+		}
+	}
+
+	l := util.Float(len(points))
+
+	avgX /= l
+	avgY /= l
+
+	if flag == 1 {
+		return avgX, util.NaN
+	} else {
+		return avgX, avgY
+	}
+}