X-Git-Url: https://arthur.barton.de/gitweb/?a=blobdiff_plain;f=src%2Frrd.c;h=ee23da0c2ebec91184c52d947d1fc46bcba7d2f3;hb=845a6a9fc1fe325f19fce1fbd34aa240ef70402a;hp=ee13a212155c636d8c78fd0c49af9768d82c80e2;hpb=037bbc245f57e45f9e6f56c705957e38586d7218;p=netdata.git

diff --git a/src/rrd.c b/src/rrd.c
old mode 100755
new mode 100644
index ee13a212..ee23da0c
--- a/src/rrd.c
+++ b/src/rrd.c
@@ -1,3 +1,7 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stddef.h>
 #include <string.h>
 #include <unistd.h>
 #include <time.h>
@@ -10,64 +14,172 @@
 #include <sys/types.h>
 #include <stdlib.h>
 
-#include "log.h"
-#include "config.h"
 #include "common.h"
+#include "log.h"
+#include "appconfig.h"
 
 #include "rrd.h"
 
-int update_every = UPDATE_EVERY;
-int save_history = HISTORY;
+#define RRD_DEFAULT_GAP_INTERPOLATIONS 1
+
+// ----------------------------------------------------------------------------
+// globals
+
+// if not zero it gives the time (in seconds) to remove un-updated dimensions
+// DO NOT ENABLE
+// if dimensions are removed, the chart generation will have to run again
+int rrd_delete_unupdated_dimensions = 0;
+
+int rrd_update_every = UPDATE_EVERY;
+int rrd_default_history_entries = RRD_DEFAULT_HISTORY_ENTRIES;
+
+RRDSET *rrdset_root = NULL;
+pthread_rwlock_t rrdset_root_rwlock = PTHREAD_RWLOCK_INITIALIZER;
+
+int rrd_memory_mode = RRD_MEMORY_MODE_SAVE;
+
+
+// ----------------------------------------------------------------------------
+// RRDSET index
+
+static int rrdset_compare(void* a, void* b) {
+	if(((RRDSET *)a)->hash < ((RRDSET *)b)->hash) return -1;
+	else if(((RRDSET *)a)->hash > ((RRDSET *)b)->hash) return 1;
+	else return strcmp(((RRDSET *)a)->id, ((RRDSET *)b)->id);
+}
+
+avl_tree_lock rrdset_root_index = {
+		{ NULL, rrdset_compare },
+		AVL_LOCK_INITIALIZER
+};
+
+#define rrdset_index_add(st) avl_insert_lock(&rrdset_root_index, (avl *)(st))
+#define rrdset_index_del(st) avl_remove_lock(&rrdset_root_index, (avl *)(st))
+
+static RRDSET *rrdset_index_find(const char *id, uint32_t hash) {
+	RRDSET tmp;
+	strncpyz(tmp.id, id, RRD_ID_LENGTH_MAX);
+	tmp.hash = (hash)?hash:simple_hash(tmp.id);
+
+	return (RRDSET *)avl_search_lock(&(rrdset_root_index), (avl *) &tmp);
+}
+
+// ----------------------------------------------------------------------------
+// RRDSET name index
+
+#define rrdset_from_avlname(avlname_ptr) ((RRDSET *)((avlname_ptr) - offsetof(RRDSET, avlname)))
+
+static int rrdset_compare_name(void* a, void* b) {
+	RRDSET *A = rrdset_from_avlname(a);
+	RRDSET *B = rrdset_from_avlname(b);
+
+	// fprintf(stderr, "COMPARING: %s with %s\n", A->name, B->name);
+
+	if(A->hash_name < B->hash_name) return -1;
+	else if(A->hash_name > B->hash_name) return 1;
+	else return strcmp(A->name, B->name);
+}
+
+avl_tree_lock rrdset_root_index_name = {
+		{ NULL, rrdset_compare_name },
+		AVL_LOCK_INITIALIZER
+};
+
+int rrdset_index_add_name(RRDSET *st) {
+	// fprintf(stderr, "ADDING: %s (name: %s)\n", st->id, st->name);
+	return avl_insert_lock(&rrdset_root_index_name, (avl *) (&st->avlname));
+}
+
+#define rrdset_index_del_name(st) avl_remove_lock(&rrdset_root_index_name, (avl *)(&st->avlname))
+
+static RRDSET *rrdset_index_find_name(const char *name, uint32_t hash) {
+	void *result = NULL;
+	RRDSET tmp;
+	tmp.name = name;
+	tmp.hash_name = (hash)?hash:simple_hash(tmp.name);
+
+	// fprintf(stderr, "SEARCHING: %s\n", name);
+	result = avl_search_lock(&(rrdset_root_index_name), (avl *) (&(tmp.avlname)));
+	if(result) {
+		RRDSET *st = rrdset_from_avlname(result);
+		if(strcmp(st->magic, RRDSET_MAGIC))
+			error("Search for RRDSET %s returned an invalid RRDSET %s (name %s)", name, st->id, st->name);
+
+		// fprintf(stderr, "FOUND: %s\n", name);
+		return rrdset_from_avlname(result);
+	}
+	// fprintf(stderr, "NOT FOUND: %s\n", name);
+	return NULL;
+}
+
+
+// ----------------------------------------------------------------------------
+// RRDDIM index
+
+static int rrddim_compare(void* a, void* b) {
+	if(((RRDDIM *)a)->hash < ((RRDDIM *)b)->hash) return -1;
+	else if(((RRDDIM *)a)->hash > ((RRDDIM *)b)->hash) return 1;
+	else return strcmp(((RRDDIM *)a)->id, ((RRDDIM *)b)->id);
+}
+
+#define rrddim_index_add(st, rd) avl_insert_lock(&((st)->dimensions_index), (avl *)(rd))
+#define rrddim_index_del(st,rd ) avl_remove_lock(&((st)->dimensions_index), (avl *)(rd))
+
+static RRDDIM *rrddim_index_find(RRDSET *st, const char *id, uint32_t hash) {
+	RRDDIM tmp;
+	strncpyz(tmp.id, id, RRD_ID_LENGTH_MAX);
+	tmp.hash = (hash)?hash:simple_hash(tmp.id);
+
+	return (RRDDIM *)avl_search_lock(&(st->dimensions_index), (avl *) &tmp);
+}
 
 // ----------------------------------------------------------------------------
 // chart types
 
-int chart_type_id(const char *name)
+int rrdset_type_id(const char *name)
 {
-	if(strcmp(name, CHART_TYPE_AREA_NAME) == 0) return CHART_TYPE_AREA;
-	if(strcmp(name, CHART_TYPE_STACKED_NAME) == 0) return CHART_TYPE_STACKED;
-	if(strcmp(name, CHART_TYPE_LINE_NAME) == 0) return CHART_TYPE_LINE;
-	return CHART_TYPE_LINE;
+	if(unlikely(strcmp(name, RRDSET_TYPE_AREA_NAME) == 0)) return RRDSET_TYPE_AREA;
+	else if(unlikely(strcmp(name, RRDSET_TYPE_STACKED_NAME) == 0)) return RRDSET_TYPE_STACKED;
+	else if(unlikely(strcmp(name, RRDSET_TYPE_LINE_NAME) == 0)) return RRDSET_TYPE_LINE;
+	return RRDSET_TYPE_LINE;
 }
 
-const char *chart_type_name(int chart_type)
+const char *rrdset_type_name(int chart_type)
 {
-	static char line[] = CHART_TYPE_LINE_NAME;
-	static char area[] = CHART_TYPE_AREA_NAME;
-	static char stacked[] = CHART_TYPE_STACKED_NAME;
+	static char line[] = RRDSET_TYPE_LINE_NAME;
+	static char area[] = RRDSET_TYPE_AREA_NAME;
+	static char stacked[] = RRDSET_TYPE_STACKED_NAME;
 
 	switch(chart_type) {
-		case CHART_TYPE_LINE:
+		case RRDSET_TYPE_LINE:
 			return line;
 
-		case CHART_TYPE_AREA:
+		case RRDSET_TYPE_AREA:
 			return area;
 
-		case CHART_TYPE_STACKED:
+		case RRDSET_TYPE_STACKED:
 			return stacked;
 	}
 	return line;
 }
 
 // ----------------------------------------------------------------------------
-// mmap() wrapper
-
-int memory_mode = NETDATA_MEMORY_MODE_SAVE;
+// load / save
 
-const char *memory_mode_name(int id)
+const char *rrd_memory_mode_name(int id)
 {
-	static const char ram[] = NETDATA_MEMORY_MODE_RAM_NAME;
-	static const char map[] = NETDATA_MEMORY_MODE_MAP_NAME;
-	static const char save[] = NETDATA_MEMORY_MODE_SAVE_NAME;
+	static const char ram[] = RRD_MEMORY_MODE_RAM_NAME;
+	static const char map[] = RRD_MEMORY_MODE_MAP_NAME;
+	static const char save[] = RRD_MEMORY_MODE_SAVE_NAME;
 
 	switch(id) {
-		case NETDATA_MEMORY_MODE_RAM:
+		case RRD_MEMORY_MODE_RAM:
 			return ram;
 
-		case NETDATA_MEMORY_MODE_MAP:
+		case RRD_MEMORY_MODE_MAP:
 			return map;
 
-		case NETDATA_MEMORY_MODE_SAVE:
+		case RRD_MEMORY_MODE_SAVE:
 		default:
 			return save;
 	}
@@ -75,55 +187,55 @@ const char *memory_mode_name(int id)
 	return save;
 }
 
-int memory_mode_id(const char *name)
+int rrd_memory_mode_id(const char *name)
 {
-	if(!strcmp(name, NETDATA_MEMORY_MODE_RAM_NAME))
-		return NETDATA_MEMORY_MODE_RAM;
-	else if(!strcmp(name, NETDATA_MEMORY_MODE_MAP_NAME))
-		return NETDATA_MEMORY_MODE_MAP;
+	if(unlikely(!strcmp(name, RRD_MEMORY_MODE_RAM_NAME)))
+		return RRD_MEMORY_MODE_RAM;
+	else if(unlikely(!strcmp(name, RRD_MEMORY_MODE_MAP_NAME)))
+		return RRD_MEMORY_MODE_MAP;
 
-	return NETDATA_MEMORY_MODE_SAVE;
+	return RRD_MEMORY_MODE_SAVE;
 }
 
 // ----------------------------------------------------------------------------
 // algorithms types
 
-int algorithm_id(const char *name)
+int rrddim_algorithm_id(const char *name)
 {
-	if(strcmp(name, RRD_DIMENSION_ABSOLUTE_NAME) == 0) 			return RRD_DIMENSION_ABSOLUTE;
-	if(strcmp(name, RRD_DIMENSION_INCREMENTAL_NAME) == 0) 			return RRD_DIMENSION_INCREMENTAL;
-	if(strcmp(name, RRD_DIMENSION_PCENT_OVER_ROW_TOTAL_NAME) == 0) 		return RRD_DIMENSION_PCENT_OVER_ROW_TOTAL;
-	if(strcmp(name, RRD_DIMENSION_PCENT_OVER_DIFF_TOTAL_NAME) == 0) 	return RRD_DIMENSION_PCENT_OVER_DIFF_TOTAL;
-	return RRD_DIMENSION_ABSOLUTE;
+	if(strcmp(name, RRDDIM_INCREMENTAL_NAME) == 0) 			return RRDDIM_INCREMENTAL;
+	if(strcmp(name, RRDDIM_ABSOLUTE_NAME) == 0) 			return RRDDIM_ABSOLUTE;
+	if(strcmp(name, RRDDIM_PCENT_OVER_ROW_TOTAL_NAME) == 0) 		return RRDDIM_PCENT_OVER_ROW_TOTAL;
+	if(strcmp(name, RRDDIM_PCENT_OVER_DIFF_TOTAL_NAME) == 0) 	return RRDDIM_PCENT_OVER_DIFF_TOTAL;
+	return RRDDIM_ABSOLUTE;
 }
 
-const char *algorithm_name(int chart_type)
+const char *rrddim_algorithm_name(int chart_type)
 {
-	static char absolute[] = RRD_DIMENSION_ABSOLUTE_NAME;
-	static char incremental[] = RRD_DIMENSION_INCREMENTAL_NAME;
-	static char percentage_of_absolute_row[] = RRD_DIMENSION_PCENT_OVER_ROW_TOTAL_NAME;
-	static char percentage_of_incremental_row[] = RRD_DIMENSION_PCENT_OVER_DIFF_TOTAL_NAME;
+	static char absolute[] = RRDDIM_ABSOLUTE_NAME;
+	static char incremental[] = RRDDIM_INCREMENTAL_NAME;
+	static char percentage_of_absolute_row[] = RRDDIM_PCENT_OVER_ROW_TOTAL_NAME;
+	static char percentage_of_incremental_row[] = RRDDIM_PCENT_OVER_DIFF_TOTAL_NAME;
 
 	switch(chart_type) {
-		case RRD_DIMENSION_ABSOLUTE:
+		case RRDDIM_ABSOLUTE:
 			return absolute;
 
-		case RRD_DIMENSION_INCREMENTAL:
+		case RRDDIM_INCREMENTAL:
 			return incremental;
 
-		case RRD_DIMENSION_PCENT_OVER_ROW_TOTAL:
+		case RRDDIM_PCENT_OVER_ROW_TOTAL:
 			return percentage_of_absolute_row;
 
-		case RRD_DIMENSION_PCENT_OVER_DIFF_TOTAL:
+		case RRDDIM_PCENT_OVER_DIFF_TOTAL:
 			return percentage_of_incremental_row;
 	}
 	return absolute;
 }
 
-RRD_STATS *root = NULL;
-pthread_rwlock_t root_rwlock = PTHREAD_RWLOCK_INITIALIZER;
+// ----------------------------------------------------------------------------
+// chart names
 
-char *rrd_stats_strncpy_name(char *to, const char *from, int length)
+char *rrdset_strncpy_name(char *to, const char *from, int length)
 {
 	int i;
 	for(i = 0; i < length && from[i] ;i++) {
@@ -136,32 +248,41 @@ char *rrd_stats_strncpy_name(char *to, const char *from, int length)
 	return to;
 }
 
-void rrd_stats_set_name(RRD_STATS *st, const char *name)
+void rrdset_set_name(RRDSET *st, const char *name)
 {
+	debug(D_RRD_CALLS, "rrdset_set_name() old: %s, new: %s", st->name, name);
+
+	if(st->name) rrdset_index_del_name(st);
+
 	char b[CONFIG_MAX_VALUE + 1];
-	char n[RRD_STATS_NAME_MAX + 1];
+	char n[RRD_ID_LENGTH_MAX + 1];
 
-	snprintf(n, RRD_STATS_NAME_MAX, "%s.%s", st->type, name);
-	rrd_stats_strncpy_name(b, n, CONFIG_MAX_VALUE);
+	snprintfz(n, RRD_ID_LENGTH_MAX, "%s.%s", st->type, name);
+	rrdset_strncpy_name(b, n, CONFIG_MAX_VALUE);
 	st->name = config_get(st->id, "name", b);
 	st->hash_name = simple_hash(st->name);
+
+	rrdset_index_add_name(st);
 }
 
-char *rrd_stats_cache_dir(const char *id)
+// ----------------------------------------------------------------------------
+// cache directory
+
+char *rrdset_cache_dir(const char *id)
 {
 	char *ret = NULL;
 
 	static char *cache_dir = NULL;
-	if(!cache_dir) cache_dir = config_get("global", "database directory", "cache");
+	if(!cache_dir) cache_dir = config_get("global", "cache directory", CACHE_DIR);
 
 	char b[FILENAME_MAX + 1];
 	char n[FILENAME_MAX + 1];
-	rrd_stats_strncpy_name(b, id, FILENAME_MAX);
+	rrdset_strncpy_name(b, id, FILENAME_MAX);
 
-	snprintf(n, FILENAME_MAX, "%s/%s", cache_dir, b);
-	ret = config_get(id, "database directory", n);
+	snprintfz(n, FILENAME_MAX, "%s/%s", cache_dir, b);
+	ret = config_get(id, "cache directory", n);
 
-	if(memory_mode == NETDATA_MEMORY_MODE_MAP || memory_mode == NETDATA_MEMORY_MODE_SAVE) {
+	if(rrd_memory_mode == RRD_MEMORY_MODE_MAP || rrd_memory_mode == RRD_MEMORY_MODE_SAVE) {
 		int r = mkdir(ret, 0775);
 		if(r != 0 && errno != EEXIST)
 			error("Cannot create directory '%s'", ret);
@@ -170,59 +291,80 @@ char *rrd_stats_cache_dir(const char *id)
 	return ret;
 }
 
-void rrd_stats_reset(RRD_STATS *st)
+// ----------------------------------------------------------------------------
+// core functions
+
+void rrdset_reset(RRDSET *st)
 {
+	debug(D_RRD_CALLS, "rrdset_reset() %s", st->name);
+
 	st->last_collected_time.tv_sec = 0;
 	st->last_collected_time.tv_usec = 0;
+	st->last_updated.tv_sec = 0;
+	st->last_updated.tv_usec = 0;
 	st->current_entry = 0;
+	st->counter = 0;
 	st->counter_done = 0;
 
-	RRD_DIMENSION *rd;
+	RRDDIM *rd;
 	for(rd = st->dimensions; rd ; rd = rd->next) {
 		rd->last_collected_time.tv_sec = 0;
 		rd->last_collected_time.tv_usec = 0;
-		rd->current_entry = 0;
+		rd->counter = 0;
+		bzero(rd->values, rd->entries * sizeof(storage_number));
 	}
 }
 
-RRD_STATS *rrd_stats_create(const char *type, const char *id, const char *name, const char *family, const char *title, const char *units, long priority, int update_every, int chart_type)
+RRDSET *rrdset_create(const char *type, const char *id, const char *name, const char *family, const char *context, const char *title, const char *units, long priority, int update_every, int chart_type)
 {
+	if(!type || !type[0]) {
+		fatal("Cannot create rrd stats without a type.");
+		return NULL;
+	}
+
 	if(!id || !id[0]) {
 		fatal("Cannot create rrd stats without an id.");
 		return NULL;
 	}
 
-	char fullid[RRD_STATS_NAME_MAX + 1];
+	char fullid[RRD_ID_LENGTH_MAX + 1];
 	char fullfilename[FILENAME_MAX + 1];
-	RRD_STATS *st = NULL;
+	RRDSET *st = NULL;
 
-	snprintf(fullid, RRD_STATS_NAME_MAX, "%s.%s", type, id);
+	snprintfz(fullid, RRD_ID_LENGTH_MAX, "%s.%s", type, id);
 
-	long entries = config_get_number(fullid, "history", save_history);
+	st = rrdset_find(fullid);
+	if(st) {
+		error("Cannot create rrd stats for '%s', it already exists.", fullid);
+		return st;
+	}
+
+	long entries = config_get_number(fullid, "history", rrd_default_history_entries);
 	if(entries < 5) entries = config_set_number(fullid, "history", 5);
-	if(entries > HISTORY_MAX) entries = config_set_number(fullid, "history", HISTORY_MAX);
+	if(entries > RRD_HISTORY_ENTRIES_MAX) entries = config_set_number(fullid, "history", RRD_HISTORY_ENTRIES_MAX);
 
 	int enabled = config_get_boolean(fullid, "enabled", 1);
 	if(!enabled) entries = 5;
 
-	unsigned long size = sizeof(RRD_STATS);
-	char *cache_dir = rrd_stats_cache_dir(fullid);
+	unsigned long size = sizeof(RRDSET);
+	char *cache_dir = rrdset_cache_dir(fullid);
 
-	debug(D_RRD_STATS, "Creating RRD_STATS for '%s.%s'.", type, id);
+	debug(D_RRD_CALLS, "Creating RRD_STATS for '%s.%s'.", type, id);
 
-	snprintf(fullfilename, FILENAME_MAX, "%s/main.db", cache_dir);
-	if(memory_mode != NETDATA_MEMORY_MODE_RAM) st = (RRD_STATS *)mymmap(fullfilename, size, ((memory_mode == NETDATA_MEMORY_MODE_MAP)?MAP_SHARED:MAP_PRIVATE));
+	snprintfz(fullfilename, FILENAME_MAX, "%s/main.db", cache_dir);
+	if(rrd_memory_mode != RRD_MEMORY_MODE_RAM) st = (RRDSET *)mymmap(fullfilename, size, ((rrd_memory_mode == RRD_MEMORY_MODE_MAP)?MAP_SHARED:MAP_PRIVATE), 0);
 	if(st) {
-		if(strcmp(st->magic, RRD_STATS_MAGIC) != 0) {
+		if(strcmp(st->magic, RRDSET_MAGIC) != 0) {
 			errno = 0;
-			error("File %s does not have our version. Clearing it.", fullfilename);
+			info("Initializing file %s.", fullfilename);
 			bzero(st, size);
 		}
 		else if(strcmp(st->id, fullid) != 0) {
 			errno = 0;
-			error("File %s does not have our id. Unmapping it.", fullfilename);
-			munmap(st, size);
-			st = NULL;
+			error("File %s contents are not for chart %s. Clearing it.", fullfilename, fullid);
+			// munmap(st, size);
+			// st = NULL;
+			bzero(st, size);
 		}
 		else if(st->memsize != size || st->entries != entries) {
 			errno = 0;
@@ -234,17 +376,23 @@ RRD_STATS *rrd_stats_create(const char *type, const char *id, const char *name,
 			error("File %s does not have the desired update frequency. Clearing it.", fullfilename);
 			bzero(st, size);
 		}
+		else if((time(NULL) - st->last_updated.tv_sec) > update_every * entries) {
+			errno = 0;
+			error("File %s is too old. Clearing it.", fullfilename);
+			bzero(st, size);
+		}
 	}
 
 	if(st) {
 		st->name = NULL;
 		st->type = NULL;
 		st->family = NULL;
+		st->context = NULL;
 		st->title = NULL;
 		st->units = NULL;
 		st->dimensions = NULL;
 		st->next = NULL;
-		st->mapped = memory_mode;
+		st->mapped = rrd_memory_mode;
 	}
 	else {
 		st = calloc(1, size);
@@ -252,37 +400,29 @@ RRD_STATS *rrd_stats_create(const char *type, const char *id, const char *name,
 			fatal("Cannot allocate memory for RRD_STATS %s.%s", type, id);
 			return NULL;
 		}
-		st->mapped = NETDATA_MEMORY_MODE_RAM;
+		st->mapped = RRD_MEMORY_MODE_RAM;
 	}
 	st->memsize = size;
 	st->entries = entries;
 	st->update_every = update_every;
 
-	strcpy(st->cache_file, fullfilename);
-	strcpy(st->magic, RRD_STATS_MAGIC);
+	strcpy(st->cache_filename, fullfilename);
+	strcpy(st->magic, RRDSET_MAGIC);
 
 	strcpy(st->id, fullid);
 	st->hash = simple_hash(st->id);
 
 	st->cache_dir = cache_dir;
 
-	st->family     = config_get(st->id, "family", family?family:st->id);
-	st->units      = config_get(st->id, "units", units?units:"");
+	st->chart_type = rrdset_type_id(config_get(st->id, "chart type", rrdset_type_name(chart_type)));
 	st->type       = config_get(st->id, "type", type);
-	st->chart_type = chart_type_id(config_get(st->id, "chart type", chart_type_name(chart_type)));
-
-	if(name && *name) rrd_stats_set_name(st, name);
-	else rrd_stats_set_name(st, id);
-
-	{
-		char varvalue[CONFIG_MAX_VALUE + 1];
-		snprintf(varvalue, CONFIG_MAX_VALUE, "%s (%s)", title?title:"", st->name);
-		st->title = config_get(st->id, "title", varvalue);
-	}
+	st->family     = config_get(st->id, "family", family?family:st->type);
+	st->context    = config_get(st->id, "context", context?context:st->id);
+	st->units      = config_get(st->id, "units", units?units:"");
 
 	st->priority = config_get_number(st->id, "priority", priority);
 	st->enabled = enabled;
-	
+
 	st->isdetail = 0;
 	st->debug = 0;
 
@@ -290,38 +430,54 @@ RRD_STATS *rrd_stats_create(const char *type, const char *id, const char *name,
 	st->last_collected_time.tv_usec = 0;
 	st->counter_done = 0;
 
+	st->gap_when_lost_iterations_above = (int) (
+			config_get_number(st->id, "gap when lost iterations above", RRD_DEFAULT_GAP_INTERPOLATIONS) + 2);
+
+	avl_init_lock(&st->dimensions_index, rrddim_compare);
+
 	pthread_rwlock_init(&st->rwlock, NULL);
-	pthread_rwlock_wrlock(&root_rwlock);
+	pthread_rwlock_wrlock(&rrdset_root_rwlock);
 
-	st->next = root;
-	root = st;
+	if(name && *name) rrdset_set_name(st, name);
+	else rrdset_set_name(st, id);
 
-	pthread_rwlock_unlock(&root_rwlock);
+	{
+		char varvalue[CONFIG_MAX_VALUE + 1];
+		snprintfz(varvalue, CONFIG_MAX_VALUE, "%s (%s)", title?title:"", st->name);
+		st->title = config_get(st->id, "title", varvalue);
+	}
+
+	st->next = rrdset_root;
+	rrdset_root = st;
+
+	rrdset_index_add(st);
+
+	pthread_rwlock_unlock(&rrdset_root_rwlock);
 
 	return(st);
 }
 
-RRD_DIMENSION *rrd_stats_dimension_add(RRD_STATS *st, const char *id, const char *name, long multiplier, long divisor, int algorithm)
+RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, long multiplier, long divisor, int algorithm)
 {
 	char filename[FILENAME_MAX + 1];
 	char fullfilename[FILENAME_MAX + 1];
 
 	char varname[CONFIG_MAX_NAME + 1];
-	RRD_DIMENSION *rd = NULL;
-	unsigned long size = sizeof(RRD_DIMENSION) + (st->entries * sizeof(storage_number));
+	RRDDIM *rd = NULL;
+	unsigned long size = sizeof(RRDDIM) + (st->entries * sizeof(storage_number));
 
-	debug(D_RRD_STATS, "Adding dimension '%s/%s'.", st->id, id);
+	debug(D_RRD_CALLS, "Adding dimension '%s/%s'.", st->id, id);
 
-	rrd_stats_strncpy_name(filename, id, FILENAME_MAX);
-	snprintf(fullfilename, FILENAME_MAX, "%s/%s.db", st->cache_dir, filename);
-	if(memory_mode != NETDATA_MEMORY_MODE_RAM) rd = (RRD_DIMENSION *)mymmap(fullfilename, size, ((memory_mode == NETDATA_MEMORY_MODE_MAP)?MAP_SHARED:MAP_PRIVATE));
+	rrdset_strncpy_name(filename, id, FILENAME_MAX);
+	snprintfz(fullfilename, FILENAME_MAX, "%s/%s.db", st->cache_dir, filename);
+	if(rrd_memory_mode != RRD_MEMORY_MODE_RAM) rd = (RRDDIM *)mymmap(fullfilename, size, ((rrd_memory_mode == RRD_MEMORY_MODE_MAP)?MAP_SHARED:MAP_PRIVATE), 1);
 	if(rd) {
 		struct timeval now;
 		gettimeofday(&now, NULL);
 
-		if(strcmp(rd->magic, RRD_DIMENSION_MAGIC) != 0) {
+		if(strcmp(rd->magic, RRDDIMENSION_MAGIC) != 0) {
 			errno = 0;
-			error("File %s does not have our version. Clearing it.", fullfilename);
+			info("Initializing file %s.", fullfilename);
 			bzero(rd, size);
 		}
 		else if(rd->memsize != size) {
@@ -356,16 +512,17 @@ RRD_DIMENSION *rrd_stats_dimension_add(RRD_STATS *st, const char *id, const char
 		}
 		else if(strcmp(rd->id, id) != 0) {
 			errno = 0;
-			error("File %s does not have our dimension id. Unmapping it.", fullfilename);
-			munmap(rd, size);
-			rd = NULL;
+			error("File %s contents are not for dimension %s. Clearing it.", fullfilename, id);
+			// munmap(rd, size);
+			// rd = NULL;
+			bzero(rd, size);
 		}
 	}
 
 	if(rd) {
 		// we have a file mapped for rd
-		rd->mapped = memory_mode;
-		rd->hidden = 0;
+		rd->mapped = rrd_memory_mode;
+		rd->flags = 0x00000000;
 		rd->next = NULL;
 		rd->name = NULL;
 	}
@@ -378,91 +535,117 @@ RRD_DIMENSION *rrd_stats_dimension_add(RRD_STATS *st, const char *id, const char
 			return NULL;
 		}
 
-		rd->mapped = NETDATA_MEMORY_MODE_RAM;
+		rd->mapped = RRD_MEMORY_MODE_RAM;
 	}
 	rd->memsize = size;
 
-	strcpy(rd->magic, RRD_DIMENSION_MAGIC);
-	strcpy(rd->cache_file, fullfilename);
-	strncpy(rd->id, id, RRD_STATS_NAME_MAX);
+	strcpy(rd->magic, RRDDIMENSION_MAGIC);
+	strcpy(rd->cache_filename, fullfilename);
+	strncpyz(rd->id, id, RRD_ID_LENGTH_MAX);
 	rd->hash = simple_hash(rd->id);
 
-	snprintf(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
+	snprintfz(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
 	rd->name = config_get(st->id, varname, (name && *name)?name:rd->id);
 
-	snprintf(varname, CONFIG_MAX_NAME, "dim %s algorithm", rd->id);
-	rd->algorithm = algorithm_id(config_get(st->id, varname, algorithm_name(algorithm)));
+	snprintfz(varname, CONFIG_MAX_NAME, "dim %s algorithm", rd->id);
+	rd->algorithm = rrddim_algorithm_id(config_get(st->id, varname, rrddim_algorithm_name(algorithm)));
 
-	snprintf(varname, CONFIG_MAX_NAME, "dim %s multiplier", rd->id);
+	snprintfz(varname, CONFIG_MAX_NAME, "dim %s multiplier", rd->id);
 	rd->multiplier = config_get_number(st->id, varname, multiplier);
 
-	snprintf(varname, CONFIG_MAX_NAME, "dim %s divisor", rd->id);
+	snprintfz(varname, CONFIG_MAX_NAME, "dim %s divisor", rd->id);
 	rd->divisor = config_get_number(st->id, varname, divisor);
 	if(!rd->divisor) rd->divisor = 1;
 
 	rd->entries = st->entries;
 	rd->update_every = st->update_every;
-	
+
+	// prevent incremental calculation spikes
+	rd->counter = 0;
+
 	// append this dimension
+	pthread_rwlock_wrlock(&st->rwlock);
 	if(!st->dimensions)
 		st->dimensions = rd;
 	else {
-		RRD_DIMENSION *td = st->dimensions;
+		RRDDIM *td = st->dimensions;
 		for(; td->next; td = td->next) ;
 		td->next = rd;
 	}
+	pthread_rwlock_unlock(&st->rwlock);
+
+	rrddim_index_add(st, rd);
 
 	return(rd);
 }
 
-void rrd_stats_dimension_set_name(RRD_STATS *st, RRD_DIMENSION *rd, const char *name)
+void rrddim_set_name(RRDSET *st, RRDDIM *rd, const char *name)
 {
+	debug(D_RRD_CALLS, "rrddim_set_name() %s.%s", st->name, rd->name);
+
 	char varname[CONFIG_MAX_NAME + 1];
-	snprintf(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
-	config_get(st->id, varname, name);
+	snprintfz(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
+	config_set_default(st->id, varname, name);
 }
 
-void rrd_stats_dimension_free(RRD_DIMENSION *rd)
+void rrddim_free(RRDSET *st, RRDDIM *rd)
 {
-	if(rd->next) rrd_stats_dimension_free(rd->next);
+	debug(D_RRD_CALLS, "rrddim_free() %s.%s", st->name, rd->name);
+
+	RRDDIM *i, *last = NULL;
+	for(i = st->dimensions; i && i != rd ; i = i->next) last = i;
+
+	if(!i) {
+		error("Request to free dimension %s.%s but it is not linked.", st->id, rd->name);
+		return;
+	}
+
+	if(last) last->next = rd->next;
+	else st->dimensions = rd->next;
+	rd->next = NULL;
+
+	rrddim_index_del(st, rd);
+
 	// free(rd->annotations);
-	if(rd->mapped == NETDATA_MEMORY_MODE_SAVE) {
-		debug(D_RRD_STATS, "Saving dimension '%s' to '%s'.", rd->name, rd->cache_file);
-		savememory(rd->cache_file, rd, rd->memsize);
+	if(rd->mapped == RRD_MEMORY_MODE_SAVE) {
+		debug(D_RRD_CALLS, "Saving dimension '%s' to '%s'.", rd->name, rd->cache_filename);
+		savememory(rd->cache_filename, rd, rd->memsize);
 
-		debug(D_RRD_STATS, "Unmapping dimension '%s'.", rd->name);
+		debug(D_RRD_CALLS, "Unmapping dimension '%s'.", rd->name);
 		munmap(rd, rd->memsize);
 	}
-	else if(rd->mapped == NETDATA_MEMORY_MODE_MAP) {
-		debug(D_RRD_STATS, "Unmapping dimension '%s'.", rd->name);
+	else if(rd->mapped == RRD_MEMORY_MODE_MAP) {
+		debug(D_RRD_CALLS, "Unmapping dimension '%s'.", rd->name);
 		munmap(rd, rd->memsize);
 	}
 	else {
-		debug(D_RRD_STATS, "Removing dimension '%s'.", rd->name);
+		debug(D_RRD_CALLS, "Removing dimension '%s'.", rd->name);
 		free(rd);
 	}
 }
 
-void rrd_stats_free_all(void)
+void rrdset_free_all(void)
 {
 	info("Freeing all memory...");
 
-	RRD_STATS *st;
-	for(st = root; st ;) {
-		RRD_STATS *next = st->next;
+	RRDSET *st;
+	for(st = rrdset_root; st ;) {
+		RRDSET *next = st->next;
 
-		if(st->dimensions) rrd_stats_dimension_free(st->dimensions);
-		st->dimensions = NULL;
+		while(st->dimensions)
+			rrddim_free(st, st->dimensions);
 
-		if(st->mapped == NETDATA_MEMORY_MODE_SAVE) {
-			debug(D_RRD_STATS, "Saving stats '%s' to '%s'.", st->name, st->cache_file);
-			savememory(st->cache_file, st, st->memsize);
+		rrdset_index_del(st);
 
-			debug(D_RRD_STATS, "Unmapping stats '%s'.", st->name);
+		if(st->mapped == RRD_MEMORY_MODE_SAVE) {
+			debug(D_RRD_CALLS, "Saving stats '%s' to '%s'.", st->name, st->cache_filename);
+			savememory(st->cache_filename, st, st->memsize);
+
+			debug(D_RRD_CALLS, "Unmapping stats '%s'.", st->name);
 			munmap(st, st->memsize);
 		}
-		else if(st->mapped == NETDATA_MEMORY_MODE_MAP) {
-			debug(D_RRD_STATS, "Unmapping stats '%s'.", st->name);
+		else if(st->mapped == RRD_MEMORY_MODE_MAP) {
+			debug(D_RRD_CALLS, "Unmapping stats '%s'.", st->name);
 			munmap(st, st->memsize);
 		}
 		else
@@ -470,203 +653,281 @@ void rrd_stats_free_all(void)
 
 		st = next;
 	}
-	root = NULL;
+	rrdset_root = NULL;
 
 	info("Memory cleanup completed...");
 }
 
-void rrd_stats_save_all(void)
+void rrdset_save_all(void)
 {
-	RRD_STATS *st;
-	RRD_DIMENSION *rd;
+	debug(D_RRD_CALLS, "rrdset_save_all()");
+
+	// let it log a few error messages
+	error_log_limit_reset();
 
-	pthread_rwlock_wrlock(&root_rwlock);
-	for(st = root; st ; st = st->next) {
+	RRDSET *st;
+	RRDDIM *rd;
+
+	pthread_rwlock_wrlock(&rrdset_root_rwlock);
+	for(st = rrdset_root; st ; st = st->next) {
 		pthread_rwlock_wrlock(&st->rwlock);
 
-		if(st->mapped == NETDATA_MEMORY_MODE_SAVE) {
-			debug(D_RRD_STATS, "Saving stats '%s' to '%s'.", st->name, st->cache_file);
-			savememory(st->cache_file, st, st->memsize);
+		if(st->mapped == RRD_MEMORY_MODE_SAVE) {
+			debug(D_RRD_CALLS, "Saving stats '%s' to '%s'.", st->name, st->cache_filename);
+			savememory(st->cache_filename, st, st->memsize);
 		}
 
 		for(rd = st->dimensions; rd ; rd = rd->next) {
-			if(rd->mapped == NETDATA_MEMORY_MODE_SAVE) {
-				debug(D_RRD_STATS, "Saving dimension '%s' to '%s'.", rd->name, rd->cache_file);
-				savememory(rd->cache_file, rd, rd->memsize);
+			if(likely(rd->mapped == RRD_MEMORY_MODE_SAVE)) {
+				debug(D_RRD_CALLS, "Saving dimension '%s' to '%s'.", rd->name, rd->cache_filename);
+				savememory(rd->cache_filename, rd, rd->memsize);
 			}
 		}
 
 		pthread_rwlock_unlock(&st->rwlock);
 	}
-	pthread_rwlock_unlock(&root_rwlock);
+	pthread_rwlock_unlock(&rrdset_root_rwlock);
 }
 
 
-RRD_STATS *rrd_stats_find(const char *id)
+RRDSET *rrdset_find(const char *id)
 {
-	unsigned long hash = simple_hash(id);
-
-	pthread_rwlock_rdlock(&root_rwlock);
-	RRD_STATS *st = root;
-	for ( ; st ; st = st->next )
-		if(hash == st->hash)
-			if(strcmp(st->id, id) == 0)
-				break;
-	pthread_rwlock_unlock(&root_rwlock);
+	debug(D_RRD_CALLS, "rrdset_find() for chart %s", id);
 
+	RRDSET *st = rrdset_index_find(id, 0);
 	return(st);
 }
 
-RRD_STATS *rrd_stats_find_bytype(const char *type, const char *id)
+RRDSET *rrdset_find_bytype(const char *type, const char *id)
 {
-	char buf[RRD_STATS_NAME_MAX + 1];
+	debug(D_RRD_CALLS, "rrdset_find_bytype() for chart %s.%s", type, id);
+
+	char buf[RRD_ID_LENGTH_MAX + 1];
 
-	strncpy(buf, type, RRD_STATS_NAME_MAX - 1);
-	buf[RRD_STATS_NAME_MAX - 1] = '\0';
+	strncpyz(buf, type, RRD_ID_LENGTH_MAX - 1);
 	strcat(buf, ".");
-	int len = strlen(buf);
-	strncpy(&buf[len], id, RRD_STATS_NAME_MAX - len);
-	buf[RRD_STATS_NAME_MAX] = '\0';
+	int len = (int) strlen(buf);
+	strncpyz(&buf[len], id, (size_t) (RRD_ID_LENGTH_MAX - len));
 
-	return(rrd_stats_find(buf));
+	return(rrdset_find(buf));
 }
 
-RRD_STATS *rrd_stats_find_byname(const char *name)
+RRDSET *rrdset_find_byname(const char *name)
 {
-	char b[CONFIG_MAX_VALUE + 1];
-
-	rrd_stats_strncpy_name(b, name, CONFIG_MAX_VALUE);
-	unsigned long hash = simple_hash(b);
-
-	pthread_rwlock_rdlock(&root_rwlock);
-	RRD_STATS *st = root;
-	for ( ; st ; st = st->next ) {
-		if(hash == st->hash_name && strcmp(st->name, b) == 0) break;
-	}
-	pthread_rwlock_unlock(&root_rwlock);
+	debug(D_RRD_CALLS, "rrdset_find_byname() for chart %s", name);
 
+	RRDSET *st = rrdset_index_find_name(name, 0);
 	return(st);
 }
 
-RRD_DIMENSION *rrd_stats_dimension_find(RRD_STATS *st, const char *id)
+RRDDIM *rrddim_find(RRDSET *st, const char *id)
 {
-	unsigned long hash = simple_hash(id);
+	debug(D_RRD_CALLS, "rrddim_find() for chart %s, dimension %s", st->name, id);
 
-	RRD_DIMENSION *rd = st->dimensions;
+	return rrddim_index_find(st, id, 0);
+}
 
-	for ( ; rd ; rd = rd->next )
-		if(hash == rd->hash)
-			if(strcmp(rd->id, id) == 0)
-				break;
+int rrddim_hide(RRDSET *st, const char *id)
+{
+	debug(D_RRD_CALLS, "rrddim_hide() for chart %s, dimension %s", st->name, id);
 
-	return(rd);
+	RRDDIM *rd = rrddim_find(st, id);
+	if(unlikely(!rd)) {
+		error("Cannot find dimension with id '%s' on stats '%s' (%s).", id, st->name, st->id);
+		return 1;
+	}
+
+	rd->flags |= RRDDIM_FLAG_HIDDEN;
+	return 0;
 }
 
-int rrd_stats_dimension_hide(RRD_STATS *st, const char *id)
+int rrddim_unhide(RRDSET *st, const char *id)
 {
-	RRD_DIMENSION *rd = rrd_stats_dimension_find(st, id);
-	if(!rd) {
+	debug(D_RRD_CALLS, "rrddim_unhide() for chart %s, dimension %s", st->name, id);
+
+	RRDDIM *rd = rrddim_find(st, id);
+	if(unlikely(!rd)) {
 		error("Cannot find dimension with id '%s' on stats '%s' (%s).", id, st->name, st->id);
 		return 1;
 	}
 
-	rd->hidden = 1;
+	if(rd->flags & RRDDIM_FLAG_HIDDEN) rd->flags ^= RRDDIM_FLAG_HIDDEN;
 	return 0;
 }
 
-void rrd_stats_dimension_set_by_pointer(RRD_STATS *st, RRD_DIMENSION *rd, collected_number value)
+collected_number rrddim_set_by_pointer(RRDSET *st, RRDDIM *rd, collected_number value)
 {
-	if(st) {;}
-	
+	debug(D_RRD_CALLS, "rrddim_set_by_pointer() for chart %s, dimension %s, value " COLLECTED_NUMBER_FORMAT, st->name, rd->name, value);
+
 	gettimeofday(&rd->last_collected_time, NULL);
 	rd->collected_value = value;
+	rd->updated = 1;
+	rd->counter++;
+
+	return rd->last_collected_value;
 }
 
-int rrd_stats_dimension_set(RRD_STATS *st, char *id, collected_number value)
+collected_number rrddim_set(RRDSET *st, const char *id, collected_number value)
 {
-	RRD_DIMENSION *rd = rrd_stats_dimension_find(st, id);
-	if(!rd) {
+	RRDDIM *rd = rrddim_find(st, id);
+	if(unlikely(!rd)) {
 		error("Cannot find dimension with id '%s' on stats '%s' (%s).", id, st->name, st->id);
-		return 1;
+		return 0;
 	}
 
-	rrd_stats_dimension_set_by_pointer(st, rd, value);
-	return 0;
+	return rrddim_set_by_pointer(st, rd, value);
 }
 
-void rrd_stats_next_usec(RRD_STATS *st, unsigned long long microseconds)
+void rrdset_next_usec(RRDSET *st, unsigned long long microseconds)
 {
-	if(st->debug) debug(D_RRD_STATS, "%s: NEXT: %llu microseconds", st->name, microseconds);
-	st->usec_since_last_update = microseconds;
+	if(!microseconds) rrdset_next(st);
+	else {
+		debug(D_RRD_CALLS, "rrdset_next_usec() for chart %s with microseconds %llu", st->name, microseconds);
+
+		if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: NEXT: %llu microseconds", st->name, microseconds);
+		st->usec_since_last_update = microseconds;
+	}
 }
 
-void rrd_stats_next(RRD_STATS *st)
+void rrdset_next(RRDSET *st)
 {
 	unsigned long long microseconds = 0;
 
-	if(st->last_collected_time.tv_sec) {
+	if(likely(st->last_collected_time.tv_sec)) {
 		struct timeval now;
 		gettimeofday(&now, NULL);
 		microseconds = usecdiff(&now, &st->last_collected_time);
 	}
+	// prevent infinite loop
+	else microseconds = st->update_every * 1000000ULL;
 
-	rrd_stats_next_usec(st, microseconds);
+	rrdset_next_usec(st, microseconds);
 }
 
-void rrd_stats_next_plugins(RRD_STATS *st)
+void rrdset_next_plugins(RRDSET *st)
 {
-	rrd_stats_next(st);
+	rrdset_next(st);
 }
 
-unsigned long long rrd_stats_done(RRD_STATS *st)
+unsigned long long rrdset_done(RRDSET *st)
 {
-	RRD_DIMENSION *rd, *last;
-	int oldstate;
+	debug(D_RRD_CALLS, "rrdset_done() for chart %s", st->name);
+
+	RRDDIM *rd, *last;
+	int oldstate, store_this_entry = 1, first_entry = 0;
+	unsigned long long last_ut, now_ut, next_ut, stored_entries = 0;
 
-	if(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate) != 0)
+	if(unlikely(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate) != 0))
 		error("Cannot set pthread cancel state to DISABLE.");
 
 	// a read lock is OK here
 	pthread_rwlock_rdlock(&st->rwlock);
 
-	if(st->debug) debug(D_RRD_STATS, "%s: microseconds since last update: %llu", st->name, st->usec_since_last_update);
+	// enable the chart, if it was disabled
+	if(unlikely(rrd_delete_unupdated_dimensions) && !st->enabled)
+		st->enabled = 1;
+
+	// check if the chart has a long time to be updated
+	if(unlikely(st->usec_since_last_update > st->entries * st->update_every * 1000000ULL)) {
+		info("%s: took too long to be updated (%0.3Lf secs). Reseting it.", st->name, (long double)(st->usec_since_last_update / 1000000.0));
+		rrdset_reset(st);
+		st->usec_since_last_update = st->update_every * 1000000ULL;
+		first_entry = 1;
+	}
+	if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: microseconds since last update: %llu", st->name, st->usec_since_last_update);
 
-	if(!st->last_collected_time.tv_sec) gettimeofday(&st->last_collected_time, NULL);
+	// set last_collected_time
+	if(unlikely(!st->last_collected_time.tv_sec)) {
+		// it is the first entry
+		// set the last_collected_time to now
+		gettimeofday(&st->last_collected_time, NULL);
+
+		// the first entry should not be stored
+		store_this_entry = 0;
+		first_entry = 1;
+
+		if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: has not set last_collected_time. Setting it now. Will not store the next entry.", st->name);
+	}
 	else {
+		// it is not the first entry
+		// calculate the proper last_collected_time, using usec_since_last_update
 		unsigned long long ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec + st->usec_since_last_update;
-		st->last_collected_time.tv_sec = ut / 1000000ULL;
-		st->last_collected_time.tv_usec = ut % 1000000ULL;
+		st->last_collected_time.tv_sec = (time_t) (ut / 1000000ULL);
+		st->last_collected_time.tv_usec = (useconds_t) (ut % 1000000ULL);
 	}
 
-	if(!st->last_updated.tv_sec) {
+	// if this set has not been updated in the past
+	// we fake the last_update time to be = now - usec_since_last_update
+	if(unlikely(!st->last_updated.tv_sec)) {
+		// it has never been updated before
+		// set a fake last_updated, in the past using usec_since_last_update
 		unsigned long long ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec - st->usec_since_last_update;
-		st->last_updated.tv_sec = ut / 1000000ULL;
-		st->last_updated.tv_usec = ut % 1000000ULL;
+		st->last_updated.tv_sec = (time_t) (ut / 1000000ULL);
+		st->last_updated.tv_usec = (useconds_t) (ut % 1000000ULL);
+
+		// the first entry should not be stored
+		store_this_entry = 0;
+		first_entry = 1;
 
-		if(st->debug) debug(D_RRD_STATS, "%s: initializing last_updated to now - %llu microseconds (%0.3Lf)", st->name, st->usec_since_last_update, (long double)ut/1000000.0);
+		if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: initializing last_updated to now - %llu microseconds (%0.3Lf). Will not store the next entry.", st->name, st->usec_since_last_update, (long double)ut/1000000.0);
 	}
 
-	unsigned long long last_ut = st->last_updated.tv_sec * 1000000ULL + st->last_updated.tv_usec;
-	unsigned long long now_ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec;
-	unsigned long long next_ut = (st->last_updated.tv_sec + st->update_every) * 1000000ULL;
+	// check if we will re-write the entire data set
+	if(unlikely(usecdiff(&st->last_collected_time, &st->last_updated) > st->update_every * st->entries * 1000000ULL)) {
+		info("%s: too old data (last updated at %u.%u, last collected at %u.%u). Reseting it. Will not store the next entry.", st->name, st->last_updated.tv_sec, st->last_updated.tv_usec, st->last_collected_time.tv_sec, st->last_collected_time.tv_usec);
+		rrdset_reset(st);
 
-	if(st->debug) debug(D_RRD_STATS, "%s: last ut = %0.3Lf (last updated time)", st->name, (long double)last_ut/1000000.0);
-	if(st->debug) debug(D_RRD_STATS, "%s: now  ut = %0.3Lf (current update time)", st->name, (long double)now_ut/1000000.0);
-	if(st->debug) debug(D_RRD_STATS, "%s: next ut = %0.3Lf (next interpolation point)", st->name, (long double)next_ut/1000000.0);
+		st->usec_since_last_update = st->update_every * 1000000ULL;
+
+		gettimeofday(&st->last_collected_time, NULL);
+
+		unsigned long long ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec - st->usec_since_last_update;
+		st->last_updated.tv_sec = (time_t) (ut / 1000000ULL);
+		st->last_updated.tv_usec = (useconds_t) (ut % 1000000ULL);
+
+		// the first entry should not be stored
+		store_this_entry = 0;
+		first_entry = 1;
+	}
+
+	// these are the 3 variables that will help us in interpolation
+	// last_ut = the last time we added a value to the storage
+	//  now_ut = the time the current value is taken at
+	// next_ut = the time of the next interpolation point
+	last_ut = st->last_updated.tv_sec * 1000000ULL + st->last_updated.tv_usec;
+	now_ut  = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec;
+	next_ut = (st->last_updated.tv_sec + st->update_every) * 1000000ULL;
+
+	if(unlikely(!first_entry && now_ut < next_ut)) {
+		if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: THIS IS IN THE SAME INTERPOLATION POINT", st->name);
+	}
 
+	if(unlikely(st->debug)) {
+		debug(D_RRD_STATS, "%s: last ut = %0.3Lf (last updated time)", st->name, (long double)last_ut/1000000.0);
+		debug(D_RRD_STATS, "%s: now  ut = %0.3Lf (current update time)", st->name, (long double)now_ut/1000000.0);
+		debug(D_RRD_STATS, "%s: next ut = %0.3Lf (next interpolation point)", st->name, (long double)next_ut/1000000.0);
+	}
+
+	if(unlikely(!st->counter_done)) {
+		store_this_entry = 0;
+		if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: Will not store the next entry.", st->name);
+	}
 	st->counter_done++;
 
 	// calculate totals and count the dimensions
 	int dimensions;
 	st->collected_total = 0;
-	for( rd = st->dimensions, dimensions = 0 ; rd ; rd = rd->next, dimensions++ )
+	for( rd = st->dimensions, dimensions = 0 ; likely(rd) ; rd = rd->next, dimensions++ )
 		st->collected_total += rd->collected_value;
 
+	uint32_t storage_flags = SN_EXISTS;
+
 	// process all dimensions to calculate their values
 	// based on the collected figures only
 	// at this stage we do not interpolate anything
-	for( rd = st->dimensions ; rd ; rd = rd->next ) {
-		if(st->debug) debug(D_RRD_STATS, "%s/%s: "
+	for( rd = st->dimensions ; likely(rd) ; rd = rd->next ) {
+
+		if(unlikely(st->debug)) debug(D_RRD_STATS, "%s/%s: START "
 			" last_collected_value = " COLLECTED_NUMBER_FORMAT
 			" collected_value = " COLLECTED_NUMBER_FORMAT
 			" last_calculated_value = " CALCULATED_NUMBER_FORMAT
@@ -679,29 +940,27 @@ unsigned long long rrd_stats_done(RRD_STATS *st)
 			);
 
 		switch(rd->algorithm) {
-			case RRD_DIMENSION_PCENT_OVER_DIFF_TOTAL:
-				// the percentage of the current increment
-				// over the increment of all dimensions together
-				if(st->collected_total == st->last_collected_total) rd->calculated_value = 0;
-				else rd->calculated_value =
-					  (calculated_number)100
-					* (calculated_number)(rd->collected_value - rd->last_collected_value)
-					/ (calculated_number)(st->collected_total  - st->last_collected_total);
-
-				if(st->debug)
-					debug(D_RRD_STATS, "%s/%s: CALC PCENT-DIFF "
-						CALCULATED_NUMBER_FORMAT " = 100"
-						" * (" COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT ")"
-						" / (" COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT ")"
-						, st->id, rd->name
-						, rd->calculated_value
-						, rd->collected_value, rd->last_collected_value
-						, st->collected_total, st->last_collected_total
-						);
-				break;
+		case RRDDIM_ABSOLUTE:
+			rd->calculated_value = (calculated_number)rd->collected_value
+				* (calculated_number)rd->multiplier
+				/ (calculated_number)rd->divisor;
+
+			if(unlikely(st->debug))
+				debug(D_RRD_STATS, "%s/%s: CALC ABS/ABS-NO-IN "
+					CALCULATED_NUMBER_FORMAT " = "
+					COLLECTED_NUMBER_FORMAT
+					" * " CALCULATED_NUMBER_FORMAT
+					" / " CALCULATED_NUMBER_FORMAT
+					, st->id, rd->name
+					, rd->calculated_value
+					, rd->collected_value
+					, (calculated_number)rd->multiplier
+					, (calculated_number)rd->divisor
+					);
+			break;
 
-			case RRD_DIMENSION_PCENT_OVER_ROW_TOTAL:
-				if(!st->collected_total) rd->calculated_value = 0;
+			case RRDDIM_PCENT_OVER_ROW_TOTAL:
+				if(unlikely(!st->collected_total)) rd->calculated_value = 0;
 				else
 				// the percentage of the current value
 				// over the total of all dimensions
@@ -710,7 +969,7 @@ unsigned long long rrd_stats_done(RRD_STATS *st)
 					* (calculated_number)rd->collected_value
 					/ (calculated_number)st->collected_total;
 
-				if(st->debug)
+				if(unlikely(st->debug))
 					debug(D_RRD_STATS, "%s/%s: CALC PCENT-ROW "
 						CALCULATED_NUMBER_FORMAT " = 100"
 						" * " COLLECTED_NUMBER_FORMAT
@@ -722,33 +981,65 @@ unsigned long long rrd_stats_done(RRD_STATS *st)
 						);
 				break;
 
-			case RRD_DIMENSION_INCREMENTAL:
+			case RRDDIM_INCREMENTAL:
+				if(unlikely(!rd->updated || rd->counter <= 1)) {
+					rd->calculated_value = 0;
+					continue;
+				}
+
 				// if the new is smaller than the old (an overflow, or reset), set the old equal to the new
 				// to reset the calculation (it will give zero as the calculation for this second)
-				if(rd->last_collected_value > rd->collected_value) rd->last_collected_value = rd->collected_value;
+				if(unlikely(rd->last_collected_value > rd->collected_value)) {
+					debug(D_RRD_STATS, "%s.%s: RESET or OVERFLOW. Last collected value = " COLLECTED_NUMBER_FORMAT ", current = " COLLECTED_NUMBER_FORMAT
+							, st->name, rd->name
+							, rd->last_collected_value
+							, rd->collected_value);
+					if(!(rd->flags & RRDDIM_FLAG_DONT_DETECT_RESETS_OR_OVERFLOWS)) storage_flags = SN_EXISTS_RESET;
+					rd->last_collected_value = rd->collected_value;
+				}
 
-				rd->calculated_value += (calculated_number)(rd->collected_value - rd->last_collected_value);
+				rd->calculated_value = (calculated_number)(rd->collected_value - rd->last_collected_value)
+					* (calculated_number)rd->multiplier
+					/ (calculated_number)rd->divisor;
 
-				if(st->debug)
-					debug(D_RRD_STATS, "%s/%s: CALC INC "
-						CALCULATED_NUMBER_FORMAT " += "
+				if(unlikely(st->debug))
+					debug(D_RRD_STATS, "%s/%s: CALC INC PRE "
+						CALCULATED_NUMBER_FORMAT " = ("
 						COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT
+						")"
+						" * " CALCULATED_NUMBER_FORMAT
+						" / " CALCULATED_NUMBER_FORMAT
 						, st->id, rd->name
 						, rd->calculated_value
 						, rd->collected_value, rd->last_collected_value
+						, (calculated_number)rd->multiplier
+						, (calculated_number)rd->divisor
 						);
 				break;
 
-			case RRD_DIMENSION_ABSOLUTE:
-				rd->calculated_value = (calculated_number)rd->collected_value;
+			case RRDDIM_PCENT_OVER_DIFF_TOTAL:
+				if(unlikely(!rd->updated || rd->counter <= 1)) {
+					rd->calculated_value = 0;
+					continue;
+				}
+
+				// the percentage of the current increment
+				// over the increment of all dimensions together
+				if(unlikely(st->collected_total == st->last_collected_total)) rd->calculated_value = rd->last_calculated_value;
+				else rd->calculated_value =
+					  (calculated_number)100
+					* (calculated_number)(rd->collected_value - rd->last_collected_value)
+					/ (calculated_number)(st->collected_total  - st->last_collected_total);
 
-				if(st->debug)
-					debug(D_RRD_STATS, "%s/%s: CALC ABS/ABS-NO-IN "
-						CALCULATED_NUMBER_FORMAT " = "
-						COLLECTED_NUMBER_FORMAT
+				if(unlikely(st->debug))
+					debug(D_RRD_STATS, "%s/%s: CALC PCENT-DIFF "
+						CALCULATED_NUMBER_FORMAT " = 100"
+						" * (" COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT ")"
+						" / (" COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT ")"
 						, st->id, rd->name
 						, rd->calculated_value
-						, rd->collected_value
+						, rd->collected_value, rd->last_collected_value
+						, st->collected_total, st->last_collected_total
 						);
 				break;
 
@@ -757,7 +1048,7 @@ unsigned long long rrd_stats_done(RRD_STATS *st)
 				// it gets noticed when we add new types
 				rd->calculated_value = 0;
 
-				if(st->debug)
+				if(unlikely(st->debug))
 					debug(D_RRD_STATS, "%s/%s: CALC "
 						CALCULATED_NUMBER_FORMAT " = 0"
 						, st->id, rd->name
@@ -765,58 +1056,53 @@ unsigned long long rrd_stats_done(RRD_STATS *st)
 						);
 				break;
 		}
-	}
-	// at this point we have all the calculated values ready
-
-	if(st->counter_done == 1 || next_ut > now_ut) {
-		// we don't have any usable data yet
-		if(st->debug) debug(D_RRD_STATS, "%s: Skipping collected values (usec since last update = %llu, counter_done = %lu)", st->name, st->usec_since_last_update, st->counter_done);
-
-		for( rd = st->dimensions; rd ; rd = rd->next ) {
-			rd->last_calculated_value = rd->calculated_value;
-			rd->last_collected_value = rd->collected_value;
-
-			switch(rd->algorithm) {
-				case RRD_DIMENSION_PCENT_OVER_DIFF_TOTAL:
-				case RRD_DIMENSION_INCREMENTAL:
-					if(!st->usec_since_last_update) rd->calculated_value = 0;
-					// keep the previous values
-					// the next time, a new incremental total will be calculated
-					break;
-			}
-
-			rd->collected_value = 0;
-		}
-		st->last_collected_total  = st->collected_total;
 
-		pthread_rwlock_unlock(&st->rwlock);
-		if(pthread_setcancelstate(oldstate, NULL) != 0)
-			error("Cannot set pthread cancel state to RESTORE (%d).", oldstate);
+		if(unlikely(st->debug)) debug(D_RRD_STATS, "%s/%s: PHASE2 "
+			" last_collected_value = " COLLECTED_NUMBER_FORMAT
+			" collected_value = " COLLECTED_NUMBER_FORMAT
+			" last_calculated_value = " CALCULATED_NUMBER_FORMAT
+			" calculated_value = " CALCULATED_NUMBER_FORMAT
+			, st->id, rd->name
+			, rd->last_collected_value
+			, rd->collected_value
+			, rd->last_calculated_value
+			, rd->calculated_value
+			);
 
-		return(st->usec_since_last_update);
 	}
 
+	// at this point we have all the calculated values ready
 	// it is now time to interpolate values on a second boundary
+
 	unsigned long long first_ut = last_ut;
-	for( ; next_ut <= now_ut ; next_ut += st->update_every * 1000000ULL ) {
-		if(st->debug) debug(D_RRD_STATS, "%s: last ut = %0.3Lf (last updated time)", st->name, (long double)last_ut/1000000.0);
-		if(st->debug) debug(D_RRD_STATS, "%s: next ut = %0.3Lf (next interpolation point)", st->name, (long double)next_ut/1000000.0);
+	long long iterations = (now_ut - last_ut) / (st->update_every * 1000000ULL);
+	if((now_ut % (st->update_every * 1000000ULL)) == 0) iterations++;
 
-		st->last_updated.tv_sec = next_ut / 1000000ULL;
+	for( ; likely(next_ut <= now_ut) ; next_ut += st->update_every * 1000000ULL, iterations-- ) {
+#ifdef NETDATA_INTERNAL_CHECKS
+		if(iterations < 0) { error("%s: iterations calculation wrapped! first_ut = %llu, last_ut = %llu, next_ut = %llu, now_ut = %llu", st->name, first_ut, last_ut, next_ut, now_ut); }
+#endif
+
+		if(unlikely(st->debug)) {
+			debug(D_RRD_STATS, "%s: last ut = %0.3Lf (last updated time)", st->name, (long double)last_ut/1000000.0);
+			debug(D_RRD_STATS, "%s: next ut = %0.3Lf (next interpolation point)", st->name, (long double)next_ut/1000000.0);
+		}
+
+		st->last_updated.tv_sec = (time_t) (next_ut / 1000000ULL);
 		st->last_updated.tv_usec = 0;
 
-		for( rd = st->dimensions ; rd ; rd = rd->next ) {
+		for( rd = st->dimensions ; likely(rd) ; rd = rd->next ) {
 			calculated_number new_value;
 
 			switch(rd->algorithm) {
-				case RRD_DIMENSION_INCREMENTAL:
+				case RRDDIM_INCREMENTAL:
 					new_value = (calculated_number)
 						(	   rd->calculated_value
 							* (calculated_number)(next_ut - last_ut)
 							/ (calculated_number)(now_ut - last_ut)
 						);
 
-					if(st->debug)
+					if(unlikely(st->debug))
 						debug(D_RRD_STATS, "%s/%s: CALC2 INC "
 							CALCULATED_NUMBER_FORMAT " = "
 							CALCULATED_NUMBER_FORMAT
@@ -825,137 +1111,210 @@ unsigned long long rrd_stats_done(RRD_STATS *st)
 							, st->id, rd->name
 							, new_value
 							, rd->calculated_value
-							, (unsigned long long)(next_ut - last_ut)
-							, (unsigned long long)(now_ut - last_ut)
+							, (next_ut - last_ut)
+							, (now_ut - last_ut)
 							);
 
 					rd->calculated_value -= new_value;
+					new_value += rd->last_calculated_value;
+					rd->last_calculated_value = 0;
+					new_value /= (calculated_number)st->update_every;
 					break;
 
-				case RRD_DIMENSION_ABSOLUTE:
-				case RRD_DIMENSION_PCENT_OVER_ROW_TOTAL:
-				case RRD_DIMENSION_PCENT_OVER_DIFF_TOTAL:
+				case RRDDIM_ABSOLUTE:
+				case RRDDIM_PCENT_OVER_ROW_TOTAL:
+				case RRDDIM_PCENT_OVER_DIFF_TOTAL:
 				default:
-					new_value = (calculated_number)
-						(	(	  (rd->calculated_value - rd->last_calculated_value)
-								* (calculated_number)(next_ut - first_ut)
-								/ (calculated_number)(now_ut - first_ut)
-							)
-							+  rd->last_calculated_value
-						);
-
-					if(st->debug)
-						debug(D_RRD_STATS, "%s/%s: CALC2 DEF "
-							CALCULATED_NUMBER_FORMAT " = ((("
-							"(" CALCULATED_NUMBER_FORMAT " - " CALCULATED_NUMBER_FORMAT ")"
-							" * %llu"
-							" / %llu) + " CALCULATED_NUMBER_FORMAT
-							, st->id, rd->name
-							, new_value
-							, rd->calculated_value, rd->last_calculated_value
-							, (next_ut - first_ut)
-							, (now_ut - first_ut), rd->last_calculated_value
+					if(iterations == 1) {
+						// this is the last iteration
+						// do not interpolate
+						// just show the calculated value
+
+						new_value = rd->calculated_value;
+					}
+					else {
+						// we have missed an update
+						// interpolate in the middle values
+
+						new_value = (calculated_number)
+							(	(	  (rd->calculated_value - rd->last_calculated_value)
+									* (calculated_number)(next_ut - first_ut)
+									/ (calculated_number)(now_ut - first_ut)
+								)
+								+  rd->last_calculated_value
 							);
 
-					if(next_ut + st->update_every * 1000000ULL > now_ut) rd->calculated_value = new_value;
+						if(unlikely(st->debug))
+							debug(D_RRD_STATS, "%s/%s: CALC2 DEF "
+								CALCULATED_NUMBER_FORMAT " = ((("
+								"(" CALCULATED_NUMBER_FORMAT " - " CALCULATED_NUMBER_FORMAT ")"
+								" * %llu"
+								" / %llu) + " CALCULATED_NUMBER_FORMAT
+								, st->id, rd->name
+								, new_value
+								, rd->calculated_value, rd->last_calculated_value
+								, (next_ut - first_ut)
+								, (now_ut - first_ut), rd->last_calculated_value
+								);
+
+						// this is wrong
+						// it fades the value towards the target
+						// while we know the calculated value is different
+						// if(likely(next_ut + st->update_every * 1000000ULL > now_ut)) rd->calculated_value = new_value;
+					}
 					break;
+			}
 
+			if(unlikely(!store_this_entry)) {
+				store_this_entry = 1;
+				continue;
 			}
 
+			if(likely(rd->updated && rd->counter > 1 && iterations < st->gap_when_lost_iterations_above)) {
+				rd->values[st->current_entry] = pack_storage_number(new_value, storage_flags );
 
-			rd->values[st->current_entry] = pack_storage_number(
-					  new_value
-					* (calculated_number)rd->multiplier
-					/ (calculated_number)rd->divisor
-				);
-
-			if(st->debug)
-				debug(D_RRD_STATS, "%s/%s: STORE[%ld] "
-					CALCULATED_NUMBER_FORMAT " = " CALCULATED_NUMBER_FORMAT
-					" * %ld"
-					" / %ld"
-					, st->id, rd->name
-					, st->current_entry
-					, unpack_storage_number(rd->values[st->current_entry]), new_value
-					, rd->multiplier
-					, rd->divisor
-					);
-		}
+				if(unlikely(st->debug))
+					debug(D_RRD_STATS, "%s/%s: STORE[%ld] "
+						CALCULATED_NUMBER_FORMAT " = " CALCULATED_NUMBER_FORMAT
+						, st->id, rd->name
+						, st->current_entry
+						, unpack_storage_number(rd->values[st->current_entry]), new_value
+						);
+			}
+			else {
+				if(unlikely(st->debug)) debug(D_RRD_STATS, "%s/%s: STORE[%ld] = NON EXISTING "
+						, st->id, rd->name
+						, st->current_entry
+						);
+				rd->values[st->current_entry] = pack_storage_number(0, SN_NOT_EXISTS);
+			}
+
+			stored_entries++;
 
-		if(st->first_entry_t && st->counter >= (unsigned long long)st->entries) {
-			// the db is overwriting values
-			// add the value we will overwrite
-			st->first_entry_t += st->update_every * 1000000ULL;
+			if(unlikely(st->debug)) {
+				calculated_number t1 = new_value * (calculated_number)rd->multiplier / (calculated_number)rd->divisor;
+				calculated_number t2 = unpack_storage_number(rd->values[st->current_entry]);
+				calculated_number accuracy = accuracy_loss(t1, t2);
+				debug(D_RRD_STATS, "%s/%s: UNPACK[%ld] = " CALCULATED_NUMBER_FORMAT " FLAGS=0x%08x (original = " CALCULATED_NUMBER_FORMAT ", accuracy loss = " CALCULATED_NUMBER_FORMAT "%%%s)"
+						, st->id, rd->name
+						, st->current_entry
+						, t2
+						, get_storage_number_flags(rd->values[st->current_entry])
+						, t1
+						, accuracy
+						, (accuracy > ACCURACY_LOSS) ? " **TOO BIG** " : ""
+						);
+
+				rd->collected_volume += t1;
+				rd->stored_volume += t2;
+				accuracy = accuracy_loss(rd->collected_volume, rd->stored_volume);
+				debug(D_RRD_STATS, "%s/%s: VOLUME[%ld] = " CALCULATED_NUMBER_FORMAT ", calculated  = " CALCULATED_NUMBER_FORMAT ", accuracy loss = " CALCULATED_NUMBER_FORMAT "%%%s"
+						, st->id, rd->name
+						, st->current_entry
+						, rd->stored_volume
+						, rd->collected_volume
+						, accuracy
+						, (accuracy > ACCURACY_LOSS) ? " **TOO BIG** " : ""
+						);
+
+			}
 		}
-		
+		// reset the storage flags for the next point, if any;
+		storage_flags = SN_EXISTS;
+
 		st->counter++;
 		st->current_entry = ((st->current_entry + 1) >= st->entries) ? 0 : st->current_entry + 1;
-		if(!st->first_entry_t) st->first_entry_t = next_ut;
 		last_ut = next_ut;
 	}
 
-	for( rd = st->dimensions; rd ; rd = rd->next ) {
-		rd->last_collected_value = rd->collected_value;
-		rd->last_calculated_value = rd->calculated_value;
+	// align next interpolation to last collection point
+	if(likely(stored_entries || !store_this_entry)) {
+		st->last_updated.tv_sec = st->last_collected_time.tv_sec;
+		st->last_updated.tv_usec = st->last_collected_time.tv_usec;
+	}
+
+	for( rd = st->dimensions; likely(rd) ; rd = rd->next ) {
+		if(unlikely(!rd->updated)) continue;
+
+		if(likely(stored_entries || !store_this_entry)) {
+			if(unlikely(st->debug)) debug(D_RRD_STATS, "%s/%s: setting last_collected_value (old: " COLLECTED_NUMBER_FORMAT ") to last_collected_value (new: " COLLECTED_NUMBER_FORMAT ")", st->id, rd->name, rd->last_collected_value, rd->collected_value);
+			rd->last_collected_value = rd->collected_value;
+
+			if(unlikely(st->debug)) debug(D_RRD_STATS, "%s/%s: setting last_calculated_value (old: " CALCULATED_NUMBER_FORMAT ") to last_calculated_value (new: " CALCULATED_NUMBER_FORMAT ")", st->id, rd->name, rd->last_calculated_value, rd->calculated_value);
+			rd->last_calculated_value = rd->calculated_value;
+		}
+
+		rd->calculated_value = 0;
 		rd->collected_value = 0;
+		rd->updated = 0;
+
+		if(unlikely(st->debug)) debug(D_RRD_STATS, "%s/%s: END "
+			" last_collected_value = " COLLECTED_NUMBER_FORMAT
+			" collected_value = " COLLECTED_NUMBER_FORMAT
+			" last_calculated_value = " CALCULATED_NUMBER_FORMAT
+			" calculated_value = " CALCULATED_NUMBER_FORMAT
+			, st->id, rd->name
+			, rd->last_collected_value
+			, rd->collected_value
+			, rd->last_calculated_value
+			, rd->calculated_value
+			);
 	}
 	st->last_collected_total  = st->collected_total;
 
 	// ALL DONE ABOUT THE DATA UPDATE
 	// --------------------------------------------------------------------
 
-
 	// find if there are any obsolete dimensions (not updated recently)
-	for( rd = st->dimensions; rd ; rd = rd->next )
-		if((rd->last_collected_time.tv_sec + (10 * st->update_every)) < st->last_collected_time.tv_sec)
-			break;
+	if(unlikely(rrd_delete_unupdated_dimensions)) {
 
-	if(rd) {
-		// there is dimension to free
-		// upgrade our read lock to a write lock
-		pthread_rwlock_unlock(&st->rwlock);
-		pthread_rwlock_wrlock(&st->rwlock);
-
-		for( rd = st->dimensions, last = NULL ; rd ; ) {
-			if((rd->last_collected_time.tv_sec + (10 * st->update_every)) < st->last_collected_time.tv_sec) { // remove it only it is not updated in 10 seconds
-				debug(D_RRD_STATS, "Removing obsolete dimension '%s' (%s) of '%s' (%s).", rd->name, rd->id, st->name, st->id);
+		for( rd = st->dimensions; likely(rd) ; rd = rd->next )
+			if((rd->last_collected_time.tv_sec + (rrd_delete_unupdated_dimensions * st->update_every)) < st->last_collected_time.tv_sec)
+				break;
 
-				if(!last) {
-					st->dimensions = rd->next;
-					rd->next = NULL;
-					rrd_stats_dimension_free(rd);
-					rd = st->dimensions;
-					continue;
-				}
-				else {
-					last->next = rd->next;
-					rd->next = NULL;
-					rrd_stats_dimension_free(rd);
-					rd = last->next;
-					continue;
+		if(unlikely(rd)) {
+			// there is dimension to free
+			// upgrade our read lock to a write lock
+			pthread_rwlock_unlock(&st->rwlock);
+			pthread_rwlock_wrlock(&st->rwlock);
+
+			for( rd = st->dimensions, last = NULL ; likely(rd) ; ) {
+				// remove it only it is not updated in rrd_delete_unupdated_dimensions seconds
+
+				if(unlikely((rd->last_collected_time.tv_sec + (rrd_delete_unupdated_dimensions * st->update_every)) < st->last_collected_time.tv_sec)) {
+					info("Removing obsolete dimension '%s' (%s) of '%s' (%s).", rd->name, rd->id, st->name, st->id);
+
+					if(unlikely(!last)) {
+						st->dimensions = rd->next;
+						rd->next = NULL;
+						rrddim_free(st, rd);
+						rd = st->dimensions;
+						continue;
+					}
+					else {
+						last->next = rd->next;
+						rd->next = NULL;
+						rrddim_free(st, rd);
+						rd = last->next;
+						continue;
+					}
 				}
+
+				last = rd;
+				rd = rd->next;
 			}
 
-			last = rd;
-			rd = rd->next;
+			if(unlikely(!st->dimensions)) {
+				info("Disabling chart %s (%s) since it does not have any dimensions", st->name, st->id);
+				st->enabled = 0;
+			}
 		}
-
-		if(!st->dimensions) st->enabled = 0;
 	}
 
 	pthread_rwlock_unlock(&st->rwlock);
 
-	if(pthread_setcancelstate(oldstate, NULL) != 0)
+	if(unlikely(pthread_setcancelstate(oldstate, NULL) != 0))
 		error("Cannot set pthread cancel state to RESTORE (%d).", oldstate);
 
 	return(st->usec_since_last_update);
 }
-
-
-// find the oldest entry in the data, skipping all empty slots
-time_t rrd_stats_first_entry_t(RRD_STATS *st)
-{
-	if(!st->first_entry_t) return st->last_updated.tv_sec;
-	
-	return st->first_entry_t / 1000000;
-}