diff --git a/include/villas/signal.h b/include/villas/signal.h
index ec9e5b8f4..56502e8f3 100644
--- a/include/villas/signal.h
+++ b/include/villas/signal.h
@@ -32,6 +32,7 @@ struct node;
 struct signal {
 	char *name;	/**< The name of the signal. */
 	char *unit;
+	int enabled;
 	enum {
 		SIGNAL_FORMAT_INTEGER,
 		SIGNAL_FORMAT_REAL
diff --git a/lib/formats/json_reserve.c b/lib/formats/json_reserve.c
index b075dbe6a..bab00bd14 100644
--- a/lib/formats/json_reserve.c
+++ b/lib/formats/json_reserve.c
@@ -31,6 +31,8 @@
 #include <villas/io.h>
 #include <villas/formats/json.h>
 
+#define JSON_RESERVE_INTEGER_TARGET 1
+
 static int json_reserve_pack_sample(struct io *io, json_t **j, struct sample *smp)
 {
 	json_error_t err;
@@ -39,7 +41,7 @@ static int json_reserve_pack_sample(struct io *io, json_t **j, struct sample *sm
 	struct signal *sig;
 
 	if (smp->flags & SAMPLE_HAS_ORIGIN)
-		json_created = json_real(time_to_double(&smp->ts.origin));
+		json_created = json_integer(time_to_double(&smp->ts.origin) * 1e3);
 
 	if (smp->flags & SAMPLE_HAS_SEQUENCE)
 		json_sequence = json_integer(smp->sequence);
@@ -53,6 +55,9 @@ static int json_reserve_pack_sample(struct io *io, json_t **j, struct sample *sm
 			sig = NULL;
 
 		if (sig) {
+			if (!sig->enabled)
+				continue;
+
 			json_name = json_string(sig->name);
 			json_unit = json_string(sig->unit);
 		}
@@ -92,10 +97,26 @@ static int json_reserve_pack_sample(struct io *io, json_t **j, struct sample *sm
 	if (*j == NULL)
 		return -1;
 
+#ifdef JSON_RESERVE_INTEGER_TARGET
+	if (io->output.node) {
+		char *endptr;
+		char *id_str = strrchr(io->output.node->name, '_');
+		if (!id_str)
+			return -1;
+
+		int id = strtoul(id_str+1, &endptr, 10);
+		if (endptr[0] != 0)
+			return -1;
+
+		json_object_set_new(*j, "target", json_integer(id));
+	}
+#else
 	if (io->output.node)
 		json_object_set_new(*j, "target", json_string(io->output.node->name));
-	//if (smp->source)
-	//	json_object_set_new(*j, "origin", json_string(smp->source->name));
+
+	if (smp->source)
+		json_object_set_new(*j, "origin", json_string(smp->source->name));
+#endif
 
 	return 0;
 }
@@ -106,23 +127,45 @@ static int json_reserve_unpack_sample(struct io *io, json_t *json_smp, struct sa
 	double created = -1;
 	json_error_t err;
 	json_t *json_value, *json_data = NULL;
+	json_t *json_origin = NULL, *json_target = NULL;
 	size_t i;
 
-	const char *origin = NULL, *target = NULL;
-
-	ret = json_unpack_ex(json_smp, &err, 0, "{ s?: s, s?: s, s?: o, s?: o }",
-		"origin", &origin,
-		"target", &target,
+	ret = json_unpack_ex(json_smp, &err, 0, "{ s?: o, s?: o, s?: o, s?: o }",
+		"origin", &json_origin,
+		"target", &json_target,
 		"measurements", &json_data,
 		"setpoints", &json_data
 	);
 	if (ret)
 		return -1;
 
-	if (target && io->input.node) {
-		if (strcmp(target, io->input.node->name))
+#ifdef JSON_RESERVE_INTEGER_TARGET
+	if (json_target && io->input.node) {
+		if (!json_is_integer(json_target))
 			return -1;
+
+		char *endptr;
+		char *id_str = strrchr(io->input.node->name, '_');
+		if (!id_str)
+			return -1;
+
+		int id = strtoul(id_str+1, &endptr, 10);
+		if (endptr[0] != 0)
+			return -1;
+
+		if (id != json_integer_value(json_target))
+			return 0;
 	}
+#else
+	if (json_target && io->input.node) {
+		const char *target = json_string_value(json_target);
+		if (!target)
+			return -1;
+
+		if (strcmp(target, io->input.node->name))
+			return 0;
+	}
+#endif
 
 	if (!json_data || !json_is_array(json_data))
 		return -1;
@@ -134,7 +177,7 @@ static int json_reserve_unpack_sample(struct io *io, json_t *json_smp, struct sa
 		const char *name, *unit = NULL;
 		double value;
 
-		ret = json_unpack_ex(json_value, &err, 0, "{ s: s, s?: s, s: f, s?: f }",
+		ret = json_unpack_ex(json_value, &err, 0, "{ s: s, s?: s, s: F, s?: F }",
 			"name", &name,
 			"unit", &unit,
 			"value", &value,
@@ -143,8 +186,16 @@ static int json_reserve_unpack_sample(struct io *io, json_t *json_smp, struct sa
 		if (ret)
 			return -1;
 
-		idx = list_lookup_index(io->input.signals, name);
-		if (idx < 0) {
+		struct signal *sig;
+
+		sig = (struct signal *) list_lookup(io->input.signals, name);
+		if (sig) {
+			if (!sig->enabled)
+				continue;
+
+			idx = list_index(io->input.signals, sig);
+		}
+		else {
 			ret = sscanf(name, "signal_%d", &idx);
 			if (ret != 1)
 				continue;
@@ -162,7 +213,7 @@ static int json_reserve_unpack_sample(struct io *io, json_t *json_smp, struct sa
 		smp->flags |= SAMPLE_HAS_VALUES;
 
 	if (created > 0) {
-		smp->ts.origin = time_from_double(created);
+		smp->ts.origin = time_from_double(created * 1e-3);
 		smp->flags |= SAMPLE_HAS_ORIGIN;
 	}
 
diff --git a/lib/mapping.c b/lib/mapping.c
index 0d7160fa7..d4432b9c9 100644
--- a/lib/mapping.c
+++ b/lib/mapping.c
@@ -137,8 +137,6 @@ int mapping_parse_str(struct mapping_entry *me, const char *str, struct list *no
 
 		first_str = strtok(NULL, "-]");
 		if (first_str) {
-			info("Mapping: %s", first_str);
-
 			if (me->node)
 				first = list_lookup_index(&me->node->in.signals, first_str);
 
diff --git a/lib/nodes/mqtt.c b/lib/nodes/mqtt.c
index 17dca2585..bc3692f13 100644
--- a/lib/nodes/mqtt.c
+++ b/lib/nodes/mqtt.c
@@ -28,110 +28,6 @@
 #include <villas/utils.h>
 #include <villas/format_type.h>
 
-//#define MQTT_THREAD 1
-
-#ifdef MQTT_THREAD
-#include <pthread.h>
-
-static struct {
-	pthread_t thread;
-	pthread_mutex_t mutex;
-	int length;
-	struct pollfd *fds;
-	struct mosquitto **clients;
-} polling = {
-	.length = 0,
-	.fds = NULL,
-	.clients = NULL
-};
-
-static pthread_t thread;
-
-static int mqtt_register_client(struct mosquitto *mosq)
-{
-	pthread_mutex_lock(&polling.mutex);
-
-	/* Add this client to the pollfd list */
-	int i = polling.length++;
-
-	polling.fds     = realloc(polling.fds,     polling.length * sizeof(struct pollfd));
-	polling.clients = realloc(polling.clients, polling.length * sizeof(struct mosquitto *));
-
-	if (!polling.fds || !polling.clients) {
-		pthread_mutex_unlock(&polling.mutex);
-		return -1;
-	}
-
-	polling.clients[i] = mosq;
-	polling.fds[i].events = POLLIN;
-	polling.fds[i].fd = mosquitto_socket(mosq);
-
-	pthread_mutex_unlock(&polling.mutex);
-
-	info("MQTT: registered new client");
-
-	return 0;
-}
-
-static int mqtt_unregister_client(struct mosquitto *mosq)
-{
-	pthread_mutex_lock(&polling.mutex);
-
-	/* Find client */
-	int i;
-	for (i = 0; i < polling.length; i++) {
-		if (polling.clients[i] == mosq)
-			break;
-	}
-
-	if (i >= polling.length) {
-		pthread_mutex_unlock(&polling.mutex);
-		return -1; /* Otherwise something wrong happened! */
-	}
-
-	/* Remove this client to the pollfd list */
-	memmove(polling.fds     + i, polling.fds     + i + 1, (polling.length - i - 1) * sizeof(struct pollfd));
-	memmove(polling.clients + i, polling.clients + i + 1, (polling.length - i - 1) * sizeof(struct mosquitto *));
-
-	polling.length--;
-
-	pthread_mutex_unlock(&polling.mutex);
-
-	info("MQTT: deregistered client");
-
-	return 0;
-}
-
-static void * mqtt_thread(void *ctx)
-{
-	int ret;
-
-	debug(5, "MQTT: started thread");
-
-	while (1) {
-//		pthread_mutex_lock(&polling.mutex);
-
-		debug(5, "MQTT: Polling on %d clients", polling.length);
-
-		ret = poll(polling.fds, polling.length, -1);
-		if (ret < 0)
-			serror("Failed to poll");
-
-		for (int i = 0; i < polling.length; i++) {
-			if (polling.fds[i].revents & POLLIN) {
-				ret = mosquitto_loop(polling.clients[i], -1, 1);
-				if (ret)
-					warn("MQTT: Loop failed for clients %p!", polling.clients[i]);
-			}
-		}
-
-//		pthread_mutex_unlock(&polling.mutex);
-	}
-
-	return NULL;
-}
-#endif
-
 static void mqtt_log_cb(struct mosquitto *mosq, void *userdata, int level, const char *str)
 {
 	switch (level) {
@@ -160,11 +56,13 @@ static void mqtt_connect_cb(struct mosquitto *mosq, void *userdata, int result)
 	struct node *n = (struct node *) userdata;
 	struct mqtt *m = (struct mqtt *) n->_vd;
 
-	debug(5, "MQTT: Node %s connected to broker %s", node_name(n), m->host);
+	int ret;
 
-#ifdef MQTT_THREAD
-	mqtt_register_client(mosq);
-#endif
+	info("MQTT: Node %s connected to broker %s", node_name(n), m->host);
+
+	ret = mosquitto_subscribe(m->client, NULL, m->subscribe, m->qos);
+	if (ret)
+		warn("MQTT: failed to subscribe to topic '%s' for node %s", m->subscribe, node_name(n));
 }
 
 static void mqtt_disconnect_cb(struct mosquitto *mosq, void *userdata, int result)
@@ -172,11 +70,7 @@ static void mqtt_disconnect_cb(struct mosquitto *mosq, void *userdata, int resul
 	struct node *n = (struct node *) userdata;
 	struct mqtt *m = (struct mqtt *) n->_vd;
 
-	debug(5, "MQTT: Node %s disconnected from broker %s", node_name(n), m->host);
-
-#ifdef MQTT_THREAD
-	mqtt_unregister_client(mosq);
-#endif
+	info("MQTT: Node %s disconnected from broker %s", node_name(n), m->host);
 }
 
 static void mqtt_message_cb(struct mosquitto *mosq, void *userdata, const struct mosquitto_message *msg)
@@ -195,8 +89,16 @@ static void mqtt_message_cb(struct mosquitto *mosq, void *userdata, const struct
 	}
 
 	ret = io_sscan(&m->io, msg->payload, msg->payloadlen, NULL, &smp, 1);
-	if (ret != 1)
+	if (ret < 0) {
+		warn("MQTT: Node %s received an invalid message", node_name(n));
+		warn("  Payload: %s", (char *) msg->payload);
 		return;
+	}
+	if (ret != 1) {
+		debug(4, "MQTT: skip empty message for node %s", node_name(n));
+		sample_put(smp);
+		return;
+	}
 
 	queue_signalled_push(&m->queue, (void *) smp);
 }
@@ -293,6 +195,15 @@ int mqtt_parse(struct node *n, json_t *cfg)
 	if (!m->format)
 		error("Invalid format '%s' for node %s", format, node_name(n));
 
+	// Some checks
+	ret = mosquitto_sub_topic_check(m->subscribe);
+	if (ret != MOSQ_ERR_SUCCESS)
+		error("Invalid subscribe topic: '%s' for node %s", m->subscribe, node_name(n));
+
+	ret = mosquitto_pub_topic_check(m->publish);
+	if (ret != MOSQ_ERR_SUCCESS)
+		error("Invalid publish topic: '%s' for node %s", m->publish, node_name(n));
+
 	return 0;
 }
 
@@ -302,14 +213,17 @@ char * mqtt_print(struct node *n)
 
 	char *buf = NULL;
 
-	strcatf(&buf, "format=%s, host=%s, port=%d, username=%s, keepalive=%s, ssl=%s", plugin_name(m->format),
+	strcatf(&buf, "format=%s, host=%s, port=%d, keepalive=%s, ssl=%s", plugin_name(m->format),
 		m->host,
 		m->port,
-		m->username,
 		m->keepalive ? "yes" : "no",
 		m->ssl.enabled ? "yes" : "no"
 	);
 
+	/* Only show if not default */
+	if (m->username)
+		strcatf(&buf, ", username=%s", m->username);
+
 	if (m->publish)
 		strcatf(&buf, ", publish=%s", m->publish);
 
@@ -361,12 +275,6 @@ int mqtt_start(struct node *n)
 	if (!m->client)
 		return -1;
 
-#ifdef MQTT_THREAD
-	ret = mosquitto_threaded_set(m->client, 1);
-	if (ret)
-		return ret;
-#endif
-
 	if (m->username && m->password) {
 		ret = mosquitto_username_pw_set(m->client, m->username, m->password);
 		if (ret)
@@ -401,19 +309,11 @@ int mqtt_start(struct node *n)
 	if (ret)
 		return ret;
 
-#ifdef MQTT_THREAD
-	mqtt_register_client(m->client);
-#else
-	ret = mosquitto_loop_start(m->client);
-	if (ret)
-		return ret;
-#endif
-
 	ret = mosquitto_connect(m->client, m->host, m->port, m->keepalive);
 	if (ret)
 		return ret;
 
-	ret = mosquitto_subscribe(m->client, NULL, m->subscribe, m->qos);
+	ret = mosquitto_loop_start(m->client);
 	if (ret)
 		return ret;
 
@@ -429,13 +329,9 @@ int mqtt_stop(struct node *n)
 	if (ret)
 		return ret;
 
-#ifdef MQTT_THREAD
-	mqtt_unregister_client(m->client);
-#else
 	ret = mosquitto_loop_stop(m->client, 0);
 	if (ret)
 		return ret;
-#endif
 
 	return 0;
 }
@@ -448,16 +344,6 @@ int mqtt_init()
 	if (ret)
 		return ret;
 
-#ifdef MQTT_THREAD
-	ret = pthread_mutex_init(&polling.mutex, NULL);
-	if (ret)
-		return ret;
-
-	ret = pthread_create(&thread, NULL, mqtt_thread, NULL);
-	if (ret)
-		return ret;
-#endif
-
 	return 0;
 }
 
@@ -465,20 +351,6 @@ int mqtt_deinit()
 {
 	int ret;
 
-#ifdef MQTT_THREAD
-	ret = pthread_cancel(thread);
-	if (ret)
-		return ret;
-
-	ret = pthread_join(thread, NULL);
-	if (ret)
-		return ret;
-
-	ret = pthread_mutex_destroy(&polling.mutex);
-	if (ret)
-		return ret;
-#endif
-
 	ret = mosquitto_lib_cleanup();
 	if (ret)
 		return ret;
diff --git a/lib/signal.c b/lib/signal.c
index 15c045fdf..cf3dbcf1e 100644
--- a/lib/signal.c
+++ b/lib/signal.c
@@ -42,9 +42,13 @@ int signal_parse(struct signal *s, json_t *cfg)
 	const char *name;
 	const char *unit = NULL;
 
-	ret = json_unpack_ex(cfg, &err, 0, "{ s: s, s?: s }",
+	/* Default values */
+	s->enabled = true;
+
+	ret = json_unpack_ex(cfg, &err, 0, "{ s: s, s?: s, s?: b }",
 		"name", &name,
-		"unit", &unit
+		"unit", &unit,
+		"enabled", &s->enabled
 	);
 	if (ret)
 		return -1;
@@ -60,6 +64,7 @@ int signal_parse(struct signal *s, json_t *cfg)
 int signal_parse_list(struct list *list, json_t *cfg)
 {
 	int ret;
+	struct signal *s;
 
 	if (!json_is_array(cfg))
 		return -1;
@@ -67,7 +72,9 @@ int signal_parse_list(struct list *list, json_t *cfg)
 	size_t index;
 	json_t *json_signal;
 	json_array_foreach(cfg, index, json_signal) {
-		struct signal *s = alloc(sizeof(struct signal));
+		s = alloc(sizeof(struct signal));
+		if (!s)
+			return -1;
 
 		ret = signal_parse(s, json_signal);
 		if (ret)
diff --git a/src/pipe.c b/src/pipe.c
index 4c887d3a0..ee27df078 100644
--- a/src/pipe.c
+++ b/src/pipe.c
@@ -160,10 +160,10 @@ static void * send_loop(void *ctx)
 		}
 
 		sent = node_write(node, smps, scanned);
-		if (sent < 0) {
+		if (sent < 0)
 			warn("Failed to sent samples to node %s: reason=%d", node_name(node), sent);
-			continue;
-		}
+		else if (sent < scanned)
+			warn("Failed to sent %d out of %d samples to node %s", scanned-sent, scanned, node_name(node));
 
 		sample_put_many(smps, ready);