Merge tag 'upstream/1.3.0+dfsg'

Upstream version 1.3.0+dfsg

1 files changed, 1275 insertions, 1088 deletions

diff --git a/src/rrd.c b/src/rrd.c
index ee23da0c2..61f99eda8 100644
--- a/src/rrd.c
+++ b/src/rrd.c
@@ -1,24 +1,4 @@
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-#include <stddef.h>
-#include <string.h>
-#include <unistd.h>
-#include <time.h>
-#include <sys/time.h>
-#include <sys/mman.h>
-#include <pthread.h>
-#include <errno.h>
-#include <ctype.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <stdlib.h>
-
 #include "common.h"
-#include "log.h"
-#include "appconfig.h"
-
-#include "rrd.h"
 
 #define RRD_DEFAULT_GAP_INTERPOLATIONS 1
 
@@ -32,36 +12,143 @@ int rrd_delete_unupdated_dimensions = 0;
 
 int rrd_update_every = UPDATE_EVERY;
 int rrd_default_history_entries = RRD_DEFAULT_HISTORY_ENTRIES;
+int rrd_memory_mode = RRD_MEMORY_MODE_SAVE;
 
-RRDSET *rrdset_root = NULL;
-pthread_rwlock_t rrdset_root_rwlock = PTHREAD_RWLOCK_INITIALIZER;
+static int rrdset_compare(void* a, void* b);
+static int rrdset_compare_name(void* a, void* b);
+static int rrdfamily_compare(void *a, void *b);
 
-int rrd_memory_mode = RRD_MEMORY_MODE_SAVE;
+// ----------------------------------------------------------------------------
+// RRDHOST
+
+RRDHOST localhost = {
+        .hostname = "localhost",
+        .rrdset_root = NULL,
+        .rrdset_root_rwlock = PTHREAD_RWLOCK_INITIALIZER,
+        .rrdset_root_index = {
+            { NULL, rrdset_compare },
+            AVL_LOCK_INITIALIZER
+        },
+        .rrdset_root_index_name = {
+            { NULL, rrdset_compare_name },
+            AVL_LOCK_INITIALIZER
+        },
+        .rrdfamily_root_index = {
+            { NULL, rrdfamily_compare },
+            AVL_LOCK_INITIALIZER
+        },
+        .variables_root_index = {
+            { NULL, rrdvar_compare },
+            AVL_LOCK_INITIALIZER
+        },
+        .health_log = {
+            .nextid = 1,
+            .count = 0,
+            .max = 1000,
+            .alarms = NULL,
+            .alarm_log_rwlock = PTHREAD_RWLOCK_INITIALIZER
+        }
+};
+
+void rrdhost_rwlock(RRDHOST *host) {
+    pthread_rwlock_wrlock(&host->rrdset_root_rwlock);
+}
+
+void rrdhost_rdlock(RRDHOST *host) {
+    pthread_rwlock_rdlock(&host->rrdset_root_rwlock);
+}
+
+void rrdhost_unlock(RRDHOST *host) {
+    pthread_rwlock_unlock(&host->rrdset_root_rwlock);
+}
+
+void rrdhost_check_rdlock_int(RRDHOST *host, const char *file, const char *function, const unsigned long line) {
+    int ret = pthread_rwlock_trywrlock(&host->rrdset_root_rwlock);
+
+    if(ret == 0)
+        fatal("RRDHOST '%s' should be read-locked, but it is not, at function %s() at line %lu of file '%s'", host->hostname, function, line, file);
+}
+
+void rrdhost_check_wrlock_int(RRDHOST *host, const char *file, const char *function, const unsigned long line) {
+    int ret = pthread_rwlock_tryrdlock(&host->rrdset_root_rwlock);
+
+    if(ret == 0)
+        fatal("RRDHOST '%s' should be write-locked, but it is not, at function %s() at line %lu of file '%s'", host->hostname, function, line, file);
+}
+
+// ----------------------------------------------------------------------------
+// RRDFAMILY index
+
+static int rrdfamily_compare(void *a, void *b) {
+    if(((RRDFAMILY *)a)->hash_family < ((RRDFAMILY *)b)->hash_family) return -1;
+    else if(((RRDFAMILY *)a)->hash_family > ((RRDFAMILY *)b)->hash_family) return 1;
+    else return strcmp(((RRDFAMILY *)a)->family, ((RRDFAMILY *)b)->family);
+}
+
+#define rrdfamily_index_add(host, rc) (RRDFAMILY *)avl_insert_lock(&((host)->rrdfamily_root_index), (avl *)(rc))
+#define rrdfamily_index_del(host, rc) (RRDFAMILY *)avl_remove_lock(&((host)->rrdfamily_root_index), (avl *)(rc))
+
+static RRDFAMILY *rrdfamily_index_find(RRDHOST *host, const char *id, uint32_t hash) {
+    RRDFAMILY tmp;
+    tmp.family = id;
+    tmp.hash_family = (hash)?hash:simple_hash(tmp.family);
+
+    return (RRDFAMILY *)avl_search_lock(&(host->rrdfamily_root_index), (avl *) &tmp);
+}
+
+RRDFAMILY *rrdfamily_create(const char *id) {
+    RRDFAMILY *rc = rrdfamily_index_find(&localhost, id, 0);
+    if(!rc) {
+        rc = callocz(1, sizeof(RRDFAMILY));
+
+        rc->family = strdupz(id);
+        rc->hash_family = simple_hash(rc->family);
+
+        // initialize the variables index
+        avl_init_lock(&rc->variables_root_index, rrdvar_compare);
 
+        RRDFAMILY *ret = rrdfamily_index_add(&localhost, rc);
+        if(ret != rc)
+            fatal("INTERNAL ERROR: Expected to INSERT RRDFAMILY '%s' into index, but inserted '%s'.", rc->family, (ret)?ret->family:"NONE");
+    }
+
+    rc->use_count++;
+    return rc;
+}
+
+void rrdfamily_free(RRDFAMILY *rc) {
+    rc->use_count--;
+    if(!rc->use_count) {
+        RRDFAMILY *ret = rrdfamily_index_del(&localhost, rc);
+        if(ret != rc)
+            fatal("INTERNAL ERROR: Expected to DELETE RRDFAMILY '%s' from index, but deleted '%s'.", rc->family, (ret)?ret->family:"NONE");
+
+        if(rc->variables_root_index.avl_tree.root != NULL)
+            fatal("INTERNAL ERROR: Variables index of RRDFAMILY '%s' that is freed, is not empty.", rc->family);
+
+        freez((void *)rc->family);
+        freez(rc);
+    }
+}
 
 // ----------------------------------------------------------------------------
 // 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);
+    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))
+#define rrdset_index_add(host, st) (RRDSET *)avl_insert_lock(&((host)->rrdset_root_index), (avl *)(st))
+#define rrdset_index_del(host, st) (RRDSET *)avl_remove_lock(&((host)->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);
+static RRDSET *rrdset_index_find(RRDHOST *host, 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);
+    return (RRDSET *)avl_search_lock(&(host->rrdset_root_index), (avl *) &tmp);
 }
 
 // ----------------------------------------------------------------------------
@@ -70,46 +157,50 @@ static RRDSET *rrdset_index_find(const char *id, uint32_t hash) {
 #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);
+    RRDSET *A = rrdset_from_avlname(a);
+    RRDSET *B = rrdset_from_avlname(b);
 
-	// fprintf(stderr, "COMPARING: %s with %s\n", A->name, B->name);
+    // 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);
+    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
-};
+RRDSET *rrdset_index_add_name(RRDHOST *host, RRDSET *st) {
+    void *result;
+    // fprintf(stderr, "ADDING: %s (name: %s)\n", st->id, st->name);
+    result = avl_insert_lock(&host->rrdset_root_index_name, (avl *) (&st->avlname));
+    if(result) return rrdset_from_avlname(result);
+    return NULL;
+}
 
-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));
+RRDSET *rrdset_index_del_name(RRDHOST *host, RRDSET *st) {
+    void *result;
+    // fprintf(stderr, "DELETING: %s (name: %s)\n", st->id, st->name);
+    result = (RRDSET *)avl_remove_lock(&((host)->rrdset_root_index_name), (avl *)(&st->avlname));
+    if(result) return rrdset_from_avlname(result);
+    return NULL;
 }
 
-#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;
+static RRDSET *rrdset_index_find_name(RRDHOST *host, 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(&host->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;
 }
 
 
@@ -117,20 +208,20 @@ static RRDSET *rrdset_index_find_name(const char *name, uint32_t hash) {
 // 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);
+    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);
+    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);
+    return (RRDDIM *)avl_search_lock(&(st->dimensions_index), (avl *) &tmp);
 }
 
 // ----------------------------------------------------------------------------
@@ -138,29 +229,29 @@ static RRDDIM *rrddim_index_find(RRDSET *st, const char *id, uint32_t hash) {
 
 int rrdset_type_id(const char *name)
 {
-	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;
+    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 *rrdset_type_name(int chart_type)
 {
-	static char line[] = RRDSET_TYPE_LINE_NAME;
-	static char area[] = RRDSET_TYPE_AREA_NAME;
-	static char stacked[] = RRDSET_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 RRDSET_TYPE_LINE:
-			return line;
+    switch(chart_type) {
+        case RRDSET_TYPE_LINE:
+            return line;
 
-		case RRDSET_TYPE_AREA:
-			return area;
+        case RRDSET_TYPE_AREA:
+            return area;
 
-		case RRDSET_TYPE_STACKED:
-			return stacked;
-	}
-	return line;
+        case RRDSET_TYPE_STACKED:
+            return stacked;
+    }
+    return line;
 }
 
 // ----------------------------------------------------------------------------
@@ -168,33 +259,33 @@ const char *rrdset_type_name(int chart_type)
 
 const char *rrd_memory_mode_name(int id)
 {
-	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;
+    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 RRD_MEMORY_MODE_RAM:
-			return ram;
+    switch(id) {
+        case RRD_MEMORY_MODE_RAM:
+            return ram;
 
-		case RRD_MEMORY_MODE_MAP:
-			return map;
+        case RRD_MEMORY_MODE_MAP:
+            return map;
 
-		case RRD_MEMORY_MODE_SAVE:
-		default:
-			return save;
-	}
+        case RRD_MEMORY_MODE_SAVE:
+        default:
+            return save;
+    }
 
-	return save;
+    return save;
 }
 
 int rrd_memory_mode_id(const char *name)
 {
-	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;
+    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 RRD_MEMORY_MODE_SAVE;
+    return RRD_MEMORY_MODE_SAVE;
 }
 
 // ----------------------------------------------------------------------------
@@ -202,67 +293,73 @@ int rrd_memory_mode_id(const char *name)
 
 int rrddim_algorithm_id(const char *name)
 {
-	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;
+    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 *rrddim_algorithm_name(int chart_type)
 {
-	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;
+    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 RRDDIM_ABSOLUTE:
-			return absolute;
+    switch(chart_type) {
+        case RRDDIM_ABSOLUTE:
+            return absolute;
 
-		case RRDDIM_INCREMENTAL:
-			return incremental;
+        case RRDDIM_INCREMENTAL:
+            return incremental;
 
-		case RRDDIM_PCENT_OVER_ROW_TOTAL:
-			return percentage_of_absolute_row;
+        case RRDDIM_PCENT_OVER_ROW_TOTAL:
+            return percentage_of_absolute_row;
 
-		case RRDDIM_PCENT_OVER_DIFF_TOTAL:
-			return percentage_of_incremental_row;
-	}
-	return absolute;
+        case RRDDIM_PCENT_OVER_DIFF_TOTAL:
+            return percentage_of_incremental_row;
+    }
+    return absolute;
 }
 
 // ----------------------------------------------------------------------------
 // chart names
 
-char *rrdset_strncpy_name(char *to, const char *from, int length)
+char *rrdset_strncpyz_name(char *to, const char *from, size_t length)
 {
-	int i;
-	for(i = 0; i < length && from[i] ;i++) {
-		if(from[i] == '.' || isalpha(from[i]) || isdigit(from[i])) to[i] = from[i];
-		else to[i] = '_';
-	}
-	if(i < length) to[i] = '\0';
-	to[length - 1] = '\0';
-
-	return to;
+    char c, *p = to;
+
+    while (length-- && (c = *from++)) {
+        if(c != '.' && !isalnum(c))
+            c = '_';
+
+        *p++ = c;
+    }
+
+    *p = '\0';
+
+    return to;
 }
 
 void rrdset_set_name(RRDSET *st, const char *name)
 {
-	debug(D_RRD_CALLS, "rrdset_set_name() old: %s, new: %s", st->name, name);
+    debug(D_RRD_CALLS, "rrdset_set_name() old: %s, new: %s", st->name, name);
 
-	if(st->name) rrdset_index_del_name(st);
+    if(st->name) {
+        rrdset_index_del_name(&localhost, st);
+        rrdsetvar_rename_all(st);
+    }
 
-	char b[CONFIG_MAX_VALUE + 1];
-	char n[RRD_ID_LENGTH_MAX + 1];
+    char b[CONFIG_MAX_VALUE + 1];
+    char n[RRD_ID_LENGTH_MAX + 1];
 
-	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);
+    snprintfz(n, RRD_ID_LENGTH_MAX, "%s.%s", st->type, name);
+    rrdset_strncpyz_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);
+    rrdset_index_add_name(&localhost, st);
 }
 
 // ----------------------------------------------------------------------------
@@ -270,25 +367,30 @@ void rrdset_set_name(RRDSET *st, const char *name)
 
 char *rrdset_cache_dir(const char *id)
 {
-	char *ret = NULL;
-
-	static char *cache_dir = NULL;
-	if(!cache_dir) cache_dir = config_get("global", "cache directory", CACHE_DIR);
-
-	char b[FILENAME_MAX + 1];
-	char n[FILENAME_MAX + 1];
-	rrdset_strncpy_name(b, id, FILENAME_MAX);
-
-	snprintfz(n, FILENAME_MAX, "%s/%s", cache_dir, b);
-	ret = config_get(id, "cache directory", n);
-
-	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);
-	}
-
-	return ret;
+    char *ret = NULL;
+
+    static char *cache_dir = NULL;
+    if(!cache_dir) {
+        cache_dir = config_get("global", "cache directory", CACHE_DIR);
+        int r = mkdir(cache_dir, 0755);
+        if(r != 0 && errno != EEXIST)
+            error("Cannot create directory '%s'", cache_dir);
+    }
+
+    char b[FILENAME_MAX + 1];
+    char n[FILENAME_MAX + 1];
+    rrdset_strncpyz_name(b, id, FILENAME_MAX);
+
+    snprintfz(n, FILENAME_MAX, "%s/%s", cache_dir, b);
+    ret = config_get(id, "cache directory", n);
+
+    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);
+    }
+
+    return ret;
 }
 
 // ----------------------------------------------------------------------------
@@ -296,1025 +398,1110 @@ char *rrdset_cache_dir(const char *id)
 
 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;
-
-	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->counter = 0;
-		bzero(rd->values, rd->entries * sizeof(storage_number));
-	}
+    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;
+
+    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->counter = 0;
+        bzero(rd->values, rd->entries * sizeof(storage_number));
+    }
 }
 
 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_ID_LENGTH_MAX + 1];
-	char fullfilename[FILENAME_MAX + 1];
-	RRDSET *st = NULL;
-
-	snprintfz(fullid, RRD_ID_LENGTH_MAX, "%s.%s", type, id);
-
-	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 > 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(RRDSET);
-	char *cache_dir = rrdset_cache_dir(fullid);
-
-	debug(D_RRD_CALLS, "Creating RRD_STATS for '%s.%s'.", type, id);
-
-	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, RRDSET_MAGIC) != 0) {
-			errno = 0;
-			info("Initializing file %s.", fullfilename);
-			bzero(st, size);
-		}
-		else if(strcmp(st->id, fullid) != 0) {
-			errno = 0;
-			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;
-			error("File %s does not have the desired size. Clearing it.", fullfilename);
-			bzero(st, size);
-		}
-		else if(st->update_every != update_every) {
-			errno = 0;
-			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 = rrd_memory_mode;
-	}
-	else {
-		st = calloc(1, size);
-		if(!st) {
-			fatal("Cannot allocate memory for RRD_STATS %s.%s", type, id);
-			return NULL;
-		}
-		st->mapped = RRD_MEMORY_MODE_RAM;
-	}
-	st->memsize = size;
-	st->entries = entries;
-	st->update_every = update_every;
-
-	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->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->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;
-
-	st->last_collected_time.tv_sec = 0;
-	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(&rrdset_root_rwlock);
-
-	if(name && *name) rrdset_set_name(st, name);
-	else rrdset_set_name(st, id);
-
-	{
-		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);
+    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_ID_LENGTH_MAX + 1];
+    char fullfilename[FILENAME_MAX + 1];
+    RRDSET *st = NULL;
+
+    snprintfz(fullid, RRD_ID_LENGTH_MAX, "%s.%s", type, id);
+
+    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 > 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(RRDSET);
+    char *cache_dir = rrdset_cache_dir(fullid);
+
+    debug(D_RRD_CALLS, "Creating RRD_STATS for '%s.%s'.", type, id);
+
+    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, RRDSET_MAGIC) != 0) {
+            errno = 0;
+            info("Initializing file %s.", fullfilename);
+            bzero(st, size);
+        }
+        else if(strcmp(st->id, fullid) != 0) {
+            errno = 0;
+            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;
+            error("File %s does not have the desired size. Clearing it.", fullfilename);
+            bzero(st, size);
+        }
+        else if(st->update_every != update_every) {
+            errno = 0;
+            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 = rrd_memory_mode;
+        st->variables = NULL;
+    }
+    else {
+        st = callocz(1, size);
+        st->mapped = RRD_MEMORY_MODE_RAM;
+    }
+
+    st->memsize = size;
+    st->entries = entries;
+    st->update_every = update_every;
+
+    if(st->current_entry >= st->entries) st->current_entry = 0;
+
+    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->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->family     = config_get(st->id, "family", family?family:st->type);
+    st->units      = config_get(st->id, "units", units?units:"");
+
+    st->context    = config_get(st->id, "context", context?context:st->id);
+    st->hash_context = simple_hash(st->context);
+
+    st->priority = config_get_number(st->id, "priority", priority);
+    st->enabled = enabled;
+
+    st->isdetail = 0;
+    st->debug = 0;
+
+    // if(!strcmp(st->id, "disk_util.dm-0")) {
+    //     st->debug = 1;
+    //     error("enabled debugging for '%s'", st->id);
+    // }
+    // else error("not enabled debugging for '%s'", st->id);
+
+    st->green = NAN;
+    st->red = NAN;
+
+    st->last_collected_time.tv_sec = 0;
+    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);
+    avl_init_lock(&st->variables_root_index, rrdvar_compare);
+
+    pthread_rwlock_init(&st->rwlock, NULL);
+    rrdhost_rwlock(&localhost);
+
+    if(name && *name) rrdset_set_name(st, name);
+    else rrdset_set_name(st, id);
+
+    {
+        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->rrdfamily = rrdfamily_create(st->family);
+    st->rrdhost = &localhost;
+
+    st->next = localhost.rrdset_root;
+    localhost.rrdset_root = st;
+
+    if(health_enabled) {
+        rrdsetvar_create(st, "last_collected_t", RRDVAR_TYPE_TIME_T, &st->last_collected_time.tv_sec, 0);
+        rrdsetvar_create(st, "collected_total_raw", RRDVAR_TYPE_TOTAL, &st->last_collected_total, 0);
+        rrdsetvar_create(st, "green", RRDVAR_TYPE_CALCULATED, &st->green, 0);
+        rrdsetvar_create(st, "red", RRDVAR_TYPE_CALCULATED, &st->red, 0);
+        rrdsetvar_create(st, "update_every", RRDVAR_TYPE_INT, &st->update_every, 0);
+    }
+
+    rrdset_index_add(&localhost, st);
+
+    rrdsetcalc_link_matching(st);
+    rrdcalctemplate_link_matching(st);
+
+    rrdhost_unlock(&localhost);
+
+    return(st);
 }
 
 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];
-	RRDDIM *rd = NULL;
-	unsigned long size = sizeof(RRDDIM) + (st->entries * sizeof(storage_number));
-
-	debug(D_RRD_CALLS, "Adding dimension '%s/%s'.", st->id, id);
-
-	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, RRDDIMENSION_MAGIC) != 0) {
-			errno = 0;
-			info("Initializing file %s.", fullfilename);
-			bzero(rd, size);
-		}
-		else if(rd->memsize != size) {
-			errno = 0;
-			error("File %s does not have the desired size. Clearing it.", fullfilename);
-			bzero(rd, size);
-		}
-		else if(rd->multiplier != multiplier) {
-			errno = 0;
-			error("File %s does not have the same multiplier. Clearing it.", fullfilename);
-			bzero(rd, size);
-		}
-		else if(rd->divisor != divisor) {
-			errno = 0;
-			error("File %s does not have the same divisor. Clearing it.", fullfilename);
-			bzero(rd, size);
-		}
-		else if(rd->algorithm != algorithm) {
-			errno = 0;
-			error("File %s does not have the same algorithm. Clearing it.", fullfilename);
-			bzero(rd, size);
-		}
-		else if(rd->update_every != st->update_every) {
-			errno = 0;
-			error("File %s does not have the same refresh frequency. Clearing it.", fullfilename);
-			bzero(rd, size);
-		}
-		else if(usecdiff(&now, &rd->last_collected_time) > (rd->entries * rd->update_every * 1000000ULL)) {
-			errno = 0;
-			error("File %s is too old. Clearing it.", fullfilename);
-			bzero(rd, size);
-		}
-		else if(strcmp(rd->id, id) != 0) {
-			errno = 0;
-			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 = rrd_memory_mode;
-		rd->flags = 0x00000000;
-		rd->next = NULL;
-		rd->name = NULL;
-	}
-	else {
-		// if we didn't manage to get a mmap'd dimension, just create one
-
-		rd = calloc(1, size);
-		if(!rd) {
-			fatal("Cannot allocate RRD_DIMENSION %s/%s.", st->id, id);
-			return NULL;
-		}
-
-		rd->mapped = RRD_MEMORY_MODE_RAM;
-	}
-	rd->memsize = size;
-
-	strcpy(rd->magic, RRDDIMENSION_MAGIC);
-	strcpy(rd->cache_filename, fullfilename);
-	strncpyz(rd->id, id, RRD_ID_LENGTH_MAX);
-	rd->hash = simple_hash(rd->id);
-
-	snprintfz(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
-	rd->name = config_get(st->id, varname, (name && *name)?name:rd->id);
-
-	snprintfz(varname, CONFIG_MAX_NAME, "dim %s algorithm", rd->id);
-	rd->algorithm = rrddim_algorithm_id(config_get(st->id, varname, rrddim_algorithm_name(algorithm)));
-
-	snprintfz(varname, CONFIG_MAX_NAME, "dim %s multiplier", rd->id);
-	rd->multiplier = config_get_number(st->id, varname, multiplier);
-
-	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 {
-		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);
+    char filename[FILENAME_MAX + 1];
+    char fullfilename[FILENAME_MAX + 1];
+
+    char varname[CONFIG_MAX_NAME + 1];
+    RRDDIM *rd = NULL;
+    unsigned long size = sizeof(RRDDIM) + (st->entries * sizeof(storage_number));
+
+    debug(D_RRD_CALLS, "Adding dimension '%s/%s'.", st->id, id);
+
+    rrdset_strncpyz_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, RRDDIMENSION_MAGIC) != 0) {
+            errno = 0;
+            info("Initializing file %s.", fullfilename);
+            bzero(rd, size);
+        }
+        else if(rd->memsize != size) {
+            errno = 0;
+            error("File %s does not have the desired size. Clearing it.", fullfilename);
+            bzero(rd, size);
+        }
+        else if(rd->multiplier != multiplier) {
+            errno = 0;
+            error("File %s does not have the same multiplier. Clearing it.", fullfilename);
+            bzero(rd, size);
+        }
+        else if(rd->divisor != divisor) {
+            errno = 0;
+            error("File %s does not have the same divisor. Clearing it.", fullfilename);
+            bzero(rd, size);
+        }
+        else if(rd->algorithm != algorithm) {
+            errno = 0;
+            error("File %s does not have the same algorithm. Clearing it.", fullfilename);
+            bzero(rd, size);
+        }
+        else if(rd->update_every != st->update_every) {
+            errno = 0;
+            error("File %s does not have the same refresh frequency. Clearing it.", fullfilename);
+            bzero(rd, size);
+        }
+        else if(usec_dt(&now, &rd->last_collected_time) > (rd->entries * rd->update_every * 1000000ULL)) {
+            errno = 0;
+            error("File %s is too old. Clearing it.", fullfilename);
+            bzero(rd, size);
+        }
+        else if(strcmp(rd->id, id) != 0) {
+            errno = 0;
+            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 = rrd_memory_mode;
+        rd->flags = 0x00000000;
+        rd->variables = NULL;
+        rd->next = NULL;
+        rd->name = NULL;
+    }
+    else {
+        // if we didn't manage to get a mmap'd dimension, just create one
+
+        rd = callocz(1, size);
+        rd->mapped = RRD_MEMORY_MODE_RAM;
+    }
+    rd->memsize = size;
+
+    strcpy(rd->magic, RRDDIMENSION_MAGIC);
+    strcpy(rd->cache_filename, fullfilename);
+    strncpyz(rd->id, id, RRD_ID_LENGTH_MAX);
+    rd->hash = simple_hash(rd->id);
+
+    snprintfz(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
+    rd->name = config_get(st->id, varname, (name && *name)?name:rd->id);
+
+    snprintfz(varname, CONFIG_MAX_NAME, "dim %s algorithm", rd->id);
+    rd->algorithm = rrddim_algorithm_id(config_get(st->id, varname, rrddim_algorithm_name(algorithm)));
+
+    snprintfz(varname, CONFIG_MAX_NAME, "dim %s multiplier", rd->id);
+    rd->multiplier = config_get_number(st->id, varname, multiplier);
+
+    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;
+    rd->updated = 0;
+    rd->calculated_value = 0;
+    rd->last_calculated_value = 0;
+    rd->collected_value = 0;
+    rd->last_collected_value = 0;
+    rd->collected_volume = 0;
+    rd->stored_volume = 0;
+    rd->last_stored_value = 0;
+    rd->values[st->current_entry] = pack_storage_number(0, SN_NOT_EXISTS);
+    rd->last_collected_time.tv_sec = 0;
+    rd->last_collected_time.tv_usec = 0;
+    rd->rrdset = st;
+
+    // append this dimension
+    pthread_rwlock_wrlock(&st->rwlock);
+    if(!st->dimensions)
+        st->dimensions = rd;
+    else {
+        RRDDIM *td = st->dimensions;
+        for(; td->next; td = td->next) ;
+        td->next = rd;
+    }
+
+    if(health_enabled) {
+        rrddimvar_create(rd, RRDVAR_TYPE_CALCULATED, NULL, NULL, &rd->last_stored_value, 0);
+        rrddimvar_create(rd, RRDVAR_TYPE_COLLECTED, NULL, "_raw", &rd->last_collected_value, 0);
+        rrddimvar_create(rd, RRDVAR_TYPE_TIME_T, NULL, "_last_collected_t", &rd->last_collected_time.tv_sec, 0);
+    }
+
+    pthread_rwlock_unlock(&st->rwlock);
+
+    rrddim_index_add(st, rd);
+
+    return(rd);
 }
 
 void rrddim_set_name(RRDSET *st, RRDDIM *rd, const char *name)
 {
-	debug(D_RRD_CALLS, "rrddim_set_name() %s.%s", st->name, rd->name);
+    debug(D_RRD_CALLS, "rrddim_set_name() %s.%s", st->name, rd->name);
+
+    char varname[CONFIG_MAX_NAME + 1];
+    snprintfz(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
+    config_set_default(st->id, varname, name);
 
-	char varname[CONFIG_MAX_NAME + 1];
-	snprintfz(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
-	config_set_default(st->id, varname, name);
+    rrddimvar_rename_all(rd);
 }
 
 void rrddim_free(RRDSET *st, RRDDIM *rd)
 {
-	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 == 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_CALLS, "Unmapping dimension '%s'.", rd->name);
-		munmap(rd, rd->memsize);
-	}
-	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_CALLS, "Removing dimension '%s'.", rd->name);
-		free(rd);
-	}
+    debug(D_RRD_CALLS, "rrddim_free() %s.%s", st->name, rd->name);
+
+    if(rd == st->dimensions)
+        st->dimensions = rd->next;
+    else {
+        RRDDIM *i;
+        for (i = st->dimensions; i && i->next != rd; i = i->next) ;
+
+        if (i && i->next == rd)
+            i->next = rd->next;
+        else
+            error("Request to free dimension '%s.%s' but it is not linked.", st->id, rd->name);
+    }
+    rd->next = NULL;
+
+    while(rd->variables)
+        rrddimvar_free(rd->variables);
+
+    rrddim_index_del(st, rd);
+
+    // free(rd->annotations);
+    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_CALLS, "Unmapping dimension '%s'.", rd->name);
+        munmap(rd, rd->memsize);
+    }
+    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_CALLS, "Removing dimension '%s'.", rd->name);
+        freez(rd);
+    }
 }
 
 void rrdset_free_all(void)
 {
-	info("Freeing all memory...");
+    info("Freeing all memory...");
 
-	RRDSET *st;
-	for(st = rrdset_root; st ;) {
-		RRDSET *next = st->next;
+    rrdhost_rwlock(&localhost);
 
-		while(st->dimensions)
-			rrddim_free(st, st->dimensions);
+    RRDSET *st;
+    for(st = localhost.rrdset_root; st ;) {
+        RRDSET *next = st->next;
 
-		rrdset_index_del(st);
+        pthread_rwlock_wrlock(&st->rwlock);
 
-		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);
+        while(st->variables)
+            rrdsetvar_free(st->variables);
 
-			debug(D_RRD_CALLS, "Unmapping stats '%s'.", st->name);
-			munmap(st, st->memsize);
-		}
-		else if(st->mapped == RRD_MEMORY_MODE_MAP) {
-			debug(D_RRD_CALLS, "Unmapping stats '%s'.", st->name);
-			munmap(st, st->memsize);
-		}
-		else
-			free(st);
+        while(st->alarms)
+            rrdsetcalc_unlink(st->alarms);
 
-		st = next;
-	}
-	rrdset_root = NULL;
+        while(st->dimensions)
+            rrddim_free(st, st->dimensions);
 
-	info("Memory cleanup completed...");
-}
+        rrdset_index_del(&localhost, st);
 
-void rrdset_save_all(void)
-{
-	debug(D_RRD_CALLS, "rrdset_save_all()");
+        st->rrdfamily->use_count--;
+        if(!st->rrdfamily->use_count)
+            rrdfamily_free(st->rrdfamily);
+
+        pthread_rwlock_unlock(&st->rwlock);
+
+        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 == RRD_MEMORY_MODE_MAP) {
+            debug(D_RRD_CALLS, "Unmapping stats '%s'.", st->name);
+            munmap(st, st->memsize);
+        }
+        else
+            freez(st);
+
+        st = next;
+    }
+    localhost.rrdset_root = NULL;
+
+    rrdhost_unlock(&localhost);
+
+    info("Memory cleanup completed...");
+}
 
-	// let it log a few error messages
-	error_log_limit_reset();
+void rrdset_save_all(void) {
+    info("Saving database...");
 
-	RRDSET *st;
-	RRDDIM *rd;
+    RRDSET *st;
+    RRDDIM *rd;
 
-	pthread_rwlock_wrlock(&rrdset_root_rwlock);
-	for(st = rrdset_root; st ; st = st->next) {
-		pthread_rwlock_wrlock(&st->rwlock);
+    rrdhost_rwlock(&localhost);
+    for(st = localhost.rrdset_root; st ; st = st->next) {
+        pthread_rwlock_wrlock(&st->rwlock);
 
-		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);
-		}
+        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(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);
-			}
-		}
+        for(rd = st->dimensions; rd ; rd = rd->next) {
+            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(&rrdset_root_rwlock);
+        pthread_rwlock_unlock(&st->rwlock);
+    }
+    rrdhost_unlock(&localhost);
 }
 
 
 RRDSET *rrdset_find(const char *id)
 {
-	debug(D_RRD_CALLS, "rrdset_find() for chart %s", id);
+    debug(D_RRD_CALLS, "rrdset_find() for chart %s", id);
 
-	RRDSET *st = rrdset_index_find(id, 0);
-	return(st);
+    RRDSET *st = rrdset_index_find(&localhost, id, 0);
+    return(st);
 }
 
 RRDSET *rrdset_find_bytype(const char *type, const char *id)
 {
-	debug(D_RRD_CALLS, "rrdset_find_bytype() for chart %s.%s", type, id);
+    debug(D_RRD_CALLS, "rrdset_find_bytype() for chart %s.%s", type, id);
 
-	char buf[RRD_ID_LENGTH_MAX + 1];
+    char buf[RRD_ID_LENGTH_MAX + 1];
 
-	strncpyz(buf, type, RRD_ID_LENGTH_MAX - 1);
-	strcat(buf, ".");
-	int len = (int) strlen(buf);
-	strncpyz(&buf[len], id, (size_t) (RRD_ID_LENGTH_MAX - len));
+    strncpyz(buf, type, RRD_ID_LENGTH_MAX - 1);
+    strcat(buf, ".");
+    int len = (int) strlen(buf);
+    strncpyz(&buf[len], id, (size_t) (RRD_ID_LENGTH_MAX - len));
 
-	return(rrdset_find(buf));
+    return(rrdset_find(buf));
 }
 
 RRDSET *rrdset_find_byname(const char *name)
 {
-	debug(D_RRD_CALLS, "rrdset_find_byname() for chart %s", name);
+    debug(D_RRD_CALLS, "rrdset_find_byname() for chart %s", name);
 
-	RRDSET *st = rrdset_index_find_name(name, 0);
-	return(st);
+    RRDSET *st = rrdset_index_find_name(&localhost, name, 0);
+    return(st);
 }
 
 RRDDIM *rrddim_find(RRDSET *st, const char *id)
 {
-	debug(D_RRD_CALLS, "rrddim_find() for chart %s, dimension %s", st->name, id);
+    debug(D_RRD_CALLS, "rrddim_find() for chart %s, dimension %s", st->name, id);
 
-	return rrddim_index_find(st, id, 0);
+    return rrddim_index_find(st, id, 0);
 }
 
 int rrddim_hide(RRDSET *st, const char *id)
 {
-	debug(D_RRD_CALLS, "rrddim_hide() for chart %s, dimension %s", st->name, id);
+    debug(D_RRD_CALLS, "rrddim_hide() 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;
-	}
+    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;
+    rd->flags |= RRDDIM_FLAG_HIDDEN;
+    return 0;
 }
 
 int rrddim_unhide(RRDSET *st, const char *id)
 {
-	debug(D_RRD_CALLS, "rrddim_unhide() for chart %s, dimension %s", st->name, id);
+    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;
-	}
+    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;
+    }
 
-	if(rd->flags & RRDDIM_FLAG_HIDDEN) rd->flags ^= RRDDIM_FLAG_HIDDEN;
-	return 0;
+    if(rd->flags & RRDDIM_FLAG_HIDDEN) rd->flags ^= RRDDIM_FLAG_HIDDEN;
+    return 0;
 }
 
 collected_number rrddim_set_by_pointer(RRDSET *st, RRDDIM *rd, collected_number value)
 {
-	debug(D_RRD_CALLS, "rrddim_set_by_pointer() for chart %s, dimension %s, value " COLLECTED_NUMBER_FORMAT, st->name, rd->name, value);
+    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++;
+    gettimeofday(&rd->last_collected_time, NULL);
+    rd->collected_value = value;
+    rd->updated = 1;
+    rd->counter++;
 
-	return rd->last_collected_value;
+    return rd->last_collected_value;
 }
 
 collected_number rrddim_set(RRDSET *st, const char *id, collected_number value)
 {
-	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 0;
-	}
+    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 0;
+    }
 
-	return rrddim_set_by_pointer(st, rd, value);
+    return rrddim_set_by_pointer(st, rd, value);
 }
 
 void rrdset_next_usec(RRDSET *st, unsigned long long microseconds)
 {
-	if(!microseconds) rrdset_next(st);
-	else {
-		debug(D_RRD_CALLS, "rrdset_next_usec() for chart %s with microseconds %llu", st->name, 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;
-	}
+        if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: NEXT: %llu microseconds", st->name, microseconds);
+        st->usec_since_last_update = microseconds;
+    }
 }
 
 void rrdset_next(RRDSET *st)
 {
-	unsigned long long microseconds = 0;
+    unsigned long long microseconds = 0;
 
-	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;
+    if(likely(st->last_collected_time.tv_sec)) {
+        struct timeval now;
+        gettimeofday(&now, NULL);
+        microseconds = usec_dt(&now, &st->last_collected_time);
+    }
+    // prevent infinite loop
+    else microseconds = st->update_every * 1000000ULL;
 
-	rrdset_next_usec(st, microseconds);
+    rrdset_next_usec(st, microseconds);
 }
 
 void rrdset_next_plugins(RRDSET *st)
 {
-	rrdset_next(st);
+    rrdset_next(st);
 }
 
 unsigned long long rrdset_done(RRDSET *st)
 {
-	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(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);
-
-	// 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);
-
-	// 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 = (time_t) (ut / 1000000ULL);
-		st->last_collected_time.tv_usec = (useconds_t) (ut % 1000000ULL);
-	}
-
-	// 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 = (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(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);
-	}
-
-	// 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);
-
-		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 ; 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 ; 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
-			" calculated_value = " CALCULATED_NUMBER_FORMAT
-			, st->id, rd->name
-			, rd->last_collected_value
-			, rd->collected_value
-			, rd->last_calculated_value
-			, rd->calculated_value
-			);
-
-		switch(rd->algorithm) {
-		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 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
-				rd->calculated_value =
-					  (calculated_number)100
-					* (calculated_number)rd->collected_value
-					/ (calculated_number)st->collected_total;
-
-				if(unlikely(st->debug))
-					debug(D_RRD_STATS, "%s/%s: CALC PCENT-ROW "
-						CALCULATED_NUMBER_FORMAT " = 100"
-						" * " COLLECTED_NUMBER_FORMAT
-						" / " COLLECTED_NUMBER_FORMAT
-						, st->id, rd->name
-						, rd->calculated_value
-						, rd->collected_value
-						, st->collected_total
-						);
-				break;
-
-			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(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)
-					* (calculated_number)rd->multiplier
-					/ (calculated_number)rd->divisor;
-
-				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 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(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->last_collected_value
-						, st->collected_total, st->last_collected_total
-						);
-				break;
-
-			default:
-				// make the default zero, to make sure
-				// it gets noticed when we add new types
-				rd->calculated_value = 0;
-
-				if(unlikely(st->debug))
-					debug(D_RRD_STATS, "%s/%s: CALC "
-						CALCULATED_NUMBER_FORMAT " = 0"
-						, st->id, rd->name
-						, rd->calculated_value
-						);
-				break;
-		}
-
-		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
-			);
-
-	}
-
-	// 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;
-	long long iterations = (now_ut - last_ut) / (st->update_every * 1000000ULL);
-	if((now_ut % (st->update_every * 1000000ULL)) == 0) iterations++;
-
-	for( ; likely(next_ut <= now_ut) ; next_ut += st->update_every * 1000000ULL, iterations-- ) {
+    if(unlikely(netdata_exit)) return 0;
+
+    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(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);
+
+    // 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);
+
+    // 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 = (time_t) (ut / 1000000ULL);
+        st->last_collected_time.tv_usec = (suseconds_t) (ut % 1000000ULL);
+    }
+
+    // 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 = (time_t) (ut / 1000000ULL);
+        st->last_updated.tv_usec = (suseconds_t) (ut % 1000000ULL);
+
+        // the first entry should not be stored
+        store_this_entry = 0;
+        first_entry = 1;
+
+        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);
+    }
+
+    // check if we will re-write the entire data set
+    if(unlikely(usec_dt(&st->last_collected_time, &st->last_updated) > st->update_every * st->entries * 1000000ULL)) {
+        info("%s: too old data (last updated at %ld.%ld, last collected at %ld.%ld). 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);
+
+        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 = (suseconds_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 ; likely(rd) ; rd = rd->next, dimensions++ )
+        if(likely(rd->updated)) 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 ; likely(rd) ; rd = rd->next ) {
+
+        if(unlikely(!rd->updated)) {
+            rd->calculated_value = 0;
+            continue;
+        }
+
+        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
+            " calculated_value = " CALCULATED_NUMBER_FORMAT
+            , st->id, rd->name
+            , rd->last_collected_value
+            , rd->collected_value
+            , rd->last_calculated_value
+            , rd->calculated_value
+            );
+
+        switch(rd->algorithm) {
+            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 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
+                    rd->calculated_value =
+                          (calculated_number)100
+                        * (calculated_number)rd->collected_value
+                        / (calculated_number)st->collected_total;
+
+                if(unlikely(st->debug))
+                    debug(D_RRD_STATS, "%s/%s: CALC PCENT-ROW "
+                        CALCULATED_NUMBER_FORMAT " = 100"
+                        " * " COLLECTED_NUMBER_FORMAT
+                        " / " COLLECTED_NUMBER_FORMAT
+                        , st->id, rd->name
+                        , rd->calculated_value
+                        , rd->collected_value
+                        , st->collected_total
+                        );
+                break;
+
+            case RRDDIM_INCREMENTAL:
+                if(unlikely(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(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)
+                    * (calculated_number)rd->multiplier
+                    / (calculated_number)rd->divisor;
+
+                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 RRDDIM_PCENT_OVER_DIFF_TOTAL:
+                if(unlikely(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(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;
+                }
+
+                // 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 = 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(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->last_collected_value
+                        , st->collected_total, st->last_collected_total
+                        );
+                break;
+
+            default:
+                // make the default zero, to make sure
+                // it gets noticed when we add new types
+                rd->calculated_value = 0;
+
+                if(unlikely(st->debug))
+                    debug(D_RRD_STATS, "%s/%s: CALC "
+                        CALCULATED_NUMBER_FORMAT " = 0"
+                        , st->id, rd->name
+                        , rd->calculated_value
+                        );
+                break;
+        }
+
+        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
+            );
+
+    }
+
+    // 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;
+    long long iterations = (now_ut - last_ut) / (st->update_every * 1000000ULL);
+    if((now_ut % (st->update_every * 1000000ULL)) == 0) iterations++;
+
+    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); }
+        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 ; likely(rd) ; rd = rd->next ) {
-			calculated_number new_value;
-
-			switch(rd->algorithm) {
-				case RRDDIM_INCREMENTAL:
-					new_value = (calculated_number)
-						(	   rd->calculated_value
-							* (calculated_number)(next_ut - last_ut)
-							/ (calculated_number)(now_ut - last_ut)
-						);
-
-					if(unlikely(st->debug))
-						debug(D_RRD_STATS, "%s/%s: CALC2 INC "
-							CALCULATED_NUMBER_FORMAT " = "
-							CALCULATED_NUMBER_FORMAT
-							" * %llu"
-							" / %llu"
-							, st->id, rd->name
-							, new_value
-							, rd->calculated_value
-							, (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 RRDDIM_ABSOLUTE:
-				case RRDDIM_PCENT_OVER_ROW_TOTAL:
-				case RRDDIM_PCENT_OVER_DIFF_TOTAL:
-				default:
-					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(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 );
-
-				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(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;
-		last_ut = next_ut;
-	}
-
-	// 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)
-	if(unlikely(rrd_delete_unupdated_dimensions)) {
-
-		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(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;
-			}
-
-			if(unlikely(!st->dimensions)) {
-				info("Disabling chart %s (%s) since it does not have any dimensions", st->name, st->id);
-				st->enabled = 0;
-			}
-		}
-	}
-
-	pthread_rwlock_unlock(&st->rwlock);
-
-	if(unlikely(pthread_setcancelstate(oldstate, NULL) != 0))
-		error("Cannot set pthread cancel state to RESTORE (%d).", oldstate);
-
-	return(st->usec_since_last_update);
+        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 ; likely(rd) ; rd = rd->next ) {
+            calculated_number new_value;
+
+            switch(rd->algorithm) {
+                case RRDDIM_INCREMENTAL:
+                    new_value = (calculated_number)
+                        (      rd->calculated_value
+                            * (calculated_number)(next_ut - last_ut)
+                            / (calculated_number)(now_ut - last_ut)
+                        );
+
+                    if(unlikely(st->debug))
+                        debug(D_RRD_STATS, "%s/%s: CALC2 INC "
+                            CALCULATED_NUMBER_FORMAT " = "
+                            CALCULATED_NUMBER_FORMAT
+                            " * %llu"
+                            " / %llu"
+                            , st->id, rd->name
+                            , new_value
+                            , rd->calculated_value
+                            , (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 RRDDIM_ABSOLUTE:
+                case RRDDIM_PCENT_OVER_ROW_TOTAL:
+                case RRDDIM_PCENT_OVER_DIFF_TOTAL:
+                default:
+                    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(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->last_stored_value = new_value;
+
+                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);
+                rd->last_stored_value = NAN;
+            }
+
+            stored_entries++;
+
+            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;
+        last_ut = next_ut;
+    }
+
+    // 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;
+        st->last_collected_total  = st->collected_total;
+    }
+
+    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
+            );
+    }
+
+    // ALL DONE ABOUT THE DATA UPDATE
+    // --------------------------------------------------------------------
+
+    // find if there are any obsolete dimensions (not updated recently)
+    if(unlikely(rrd_delete_unupdated_dimensions)) {
+
+        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(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;
+            }
+
+            if(unlikely(!st->dimensions)) {
+                info("Disabling chart %s (%s) since it does not have any dimensions", st->name, st->id);
+                st->enabled = 0;
+            }
+        }
+    }
+
+    pthread_rwlock_unlock(&st->rwlock);
+
+    if(unlikely(pthread_setcancelstate(oldstate, NULL) != 0))
+        error("Cannot set pthread cancel state to RESTORE (%d).", oldstate);
+
+    return(st->usec_since_last_update);
 }