diff --git a/lib/hooks/stats.cpp b/lib/hooks/stats.cpp
index c96d30819..e422f3bd4 100644
--- a/lib/hooks/stats.cpp
+++ b/lib/hooks/stats.cpp
@@ -37,11 +37,103 @@
 namespace villas {
 namespace node {
 
+class StatsHook;
+
+class StatsWriteHook : public Hook {
+
+protected:
+	StatsHook *parent;
+
+public:
+	StatsWriteHook(struct path *p, struct node *n, int fl, int prio, bool en = true) :
+		Hook(p, n, fl, prio, en)
+	{
+		state = STATE_CHECKED;
+	}
+
+	virtual int process(sample *smp)
+	{
+		stats *s = node->stats;
+
+		timespec now = time_now();
+
+		stats_update(s, STATS_METRIC_AGE, time_delta(&smp->ts.received, &now));
+
+		return HOOK_OK;
+	}
+};
+
+class StatsReadHook : public Hook {
+
+protected:
+	sample *last;
+
+public:
+	StatsReadHook(struct path *p, struct node *n, int fl, int prio, bool en = true) :
+		Hook(p, n, fl, prio, en)
+	{
+		state = STATE_CHECKED;
+	}
+
+	virtual void start()
+	{
+		assert(state == STATE_PREPARED);
+
+		last = nullptr;
+
+		state = STATE_STARTED;
+	}
+
+	virtual void stop()
+	{
+		assert(state == STATE_STARTED);
+
+		if (last)
+			sample_decref(last);
+
+		state = STATE_STOPPED;
+	}
+
+	virtual int process(sample *smp)
+	{
+		stats *s = node->stats;
+
+		if (last) {
+			if (smp->flags & last->flags & SAMPLE_HAS_TS_RECEIVED)
+				stats_update(s, STATS_METRIC_GAP_RECEIVED, time_delta(&last->ts.received, &smp->ts.received));
+
+			if (smp->flags & last->flags & SAMPLE_HAS_TS_ORIGIN)
+				stats_update(s, STATS_METRIC_GAP_SAMPLE, time_delta(&last->ts.origin, &smp->ts.origin));
+
+			if ((smp->flags & SAMPLE_HAS_TS_ORIGIN) && (smp->flags & SAMPLE_HAS_TS_RECEIVED))
+				stats_update(s, STATS_METRIC_OWD, time_delta(&smp->ts.origin, &smp->ts.received));
+
+			if (smp->flags & last->flags & SAMPLE_HAS_SEQUENCE) {
+				int dist = smp->sequence - (int32_t) last->sequence;
+				if (dist != 1)
+					stats_update(s, STATS_METRIC_SMPS_REORDERED, dist);
+			}
+		}
+
+		sample_incref(smp);
+
+		if (last)
+			sample_decref(last);
+
+		last = smp;
+
+		return HOOK_OK;
+	}
+};
+
 class StatsHook : public Hook {
 
 protected:
 	struct stats stats;
 
+	StatsReadHook *readHook;
+	StatsWriteHook *writeHook;
+
 	enum stats_format format;
 	int verbose;
 	int warmup;
@@ -50,8 +142,6 @@ protected:
 	AFILE *output;
 	char *uri;
 
-	sample *last;
-
 public:
 
 	StatsHook(struct path *p, struct node *n, int fl, int prio, bool en = true) :
@@ -68,8 +158,14 @@ public:
 		/* Register statistic object to path.
 		*
 		* This allows the path code to update statistics. */
-		if (node)
-			node->stats = &stats;
+		node->stats = &stats;
+
+		/* Add child hooks */
+		readHook = new StatsReadHook(p, n, fl, prio, en);
+		writeHook = new StatsWriteHook(p, n, fl, prio, en);
+
+		vlist_push(&node->in.hooks, (void *) readHook);
+		vlist_push(&node->out.hooks, (void *) writeHook);
 	}
 
 	~StatsHook()
@@ -165,37 +261,6 @@ public:
 
 		state = STATE_PARSED;
 	}
-
-	virtual int process(sample *smp)
-	{
-		struct stats *s = &stats;
-
-		if (last) {
-			if (smp->flags & last->flags & SAMPLE_HAS_TS_RECEIVED)
-				stats_update(s, STATS_METRIC_GAP_RECEIVED, time_delta(&last->ts.received, &smp->ts.received));
-
-			if (smp->flags & last->flags & SAMPLE_HAS_TS_ORIGIN)
-				stats_update(s, STATS_METRIC_GAP_SAMPLE, time_delta(&last->ts.origin, &smp->ts.origin));
-
-			if ((smp->flags & SAMPLE_HAS_TS_ORIGIN) && (smp->flags & SAMPLE_HAS_TS_RECEIVED))
-				stats_update(s, STATS_METRIC_OWD, time_delta(&smp->ts.origin, &smp->ts.received));
-
-			if (smp->flags & last->flags & SAMPLE_HAS_SEQUENCE) {
-				int dist = smp->sequence - (int32_t) last->sequence;
-				if (dist != 1)
-					stats_update(s, STATS_METRIC_SMPS_REORDERED, dist);
-			}
-		}
-
-		sample_incref(smp);
-
-		if (last)
-			sample_decref(last);
-
-		last = smp;
-
-		return HOOK_OK;
-	}
 };
 
 /* Register hook */