]> arthur.barton.de Git - netdata.git/blobdiff - src/rrd.c
multi-host rrdset and rrdfamily operations
[netdata.git] / src / rrd.c
index 2b70e72a724d00a4e377282d26a6d391896fdac7..65c5f890d01b47350cc8f7310b2993a6b0622764 100644 (file)
--- a/src/rrd.c
+++ b/src/rrd.c
@@ -14,7 +14,7 @@ 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;
+RRD_MEMORY_MODE rrd_memory_mode = RRD_MEMORY_MODE_SAVE;
 
 static int rrdset_compare(void* a, void* b);
 static int rrdset_compare_name(void* a, void* b);
@@ -56,7 +56,7 @@ RRDHOST localhost = {
 void rrdhost_init(char *hostname) {
     localhost.hostname = hostname;
     localhost.health_log.next_log_id =
-        localhost.health_log.next_alarm_id = time(NULL);
+        localhost.health_log.next_alarm_id = now_realtime_sec();
 }
 
 void rrdhost_rwlock(RRDHOST *host) {
@@ -105,8 +105,8 @@ static RRDFAMILY *rrdfamily_index_find(RRDHOST *host, const char *id, uint32_t h
     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);
+RRDFAMILY *rrdfamily_create(RRDHOST *host, const char *id) {
+    RRDFAMILY *rc = rrdfamily_index_find(host, id, 0);
     if(!rc) {
         rc = callocz(1, sizeof(RRDFAMILY));
 
@@ -116,24 +116,24 @@ RRDFAMILY *rrdfamily_create(const char *id) {
         // initialize the variables index
         avl_init_lock(&rc->variables_root_index, rrdvar_compare);
 
-        RRDFAMILY *ret = rrdfamily_index_add(&localhost, rc);
+        RRDFAMILY *ret = rrdfamily_index_add(host, rc);
         if(ret != rc)
-            fatal("INTERNAL ERROR: Expected to INSERT RRDFAMILY '%s' into index, but inserted '%s'.", rc->family, (ret)?ret->family:"NONE");
+            fatal("RRDFAMILY: 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) {
+void rrdfamily_free(RRDHOST *host, RRDFAMILY *rc) {
     rc->use_count--;
     if(!rc->use_count) {
-        RRDFAMILY *ret = rrdfamily_index_del(&localhost, rc);
+        RRDFAMILY *ret = rrdfamily_index_del(host, rc);
         if(ret != rc)
-            fatal("INTERNAL ERROR: Expected to DELETE RRDFAMILY '%s' from index, but deleted '%s'.", rc->family, (ret)?ret->family:"NONE");
+            fatal("RRDFAMILY: 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);
+            fatal("RRDFAMILY: INTERNAL ERROR: Variables index of RRDFAMILY '%s' that is freed, is not empty.", rc->family);
 
         freez((void *)rc->family);
         freez(rc);
@@ -222,69 +222,60 @@ static int rrddim_compare(void* a, void* b) {
     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))
+#define rrddim_index_add(st, rd) (RRDDIM *)avl_insert_lock(&((st)->dimensions_index), (avl *)(rd))
+#define rrddim_index_del(st,rd ) (RRDDIM *)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 = {
+            .id = id,
+            .hash = (hash)?hash:simple_hash(id)
+    };
     return (RRDDIM *)avl_search_lock(&(st->dimensions_index), (avl *) &tmp);
 }
 
 // ----------------------------------------------------------------------------
 // chart types
 
-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;
-}
+inline RRDSET_TYPE rrdset_type_id(const char *name) {
+    if(unlikely(strcmp(name, RRDSET_TYPE_AREA_NAME) == 0))
+        return RRDSET_TYPE_AREA;
 
-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;
+    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;
+}
 
+const char *rrdset_type_name(RRDSET_TYPE chart_type) {
     switch(chart_type) {
         case RRDSET_TYPE_LINE:
-            return line;
+        default:
+            return RRDSET_TYPE_LINE_NAME;
 
         case RRDSET_TYPE_AREA:
-            return area;
+            return RRDSET_TYPE_AREA_NAME;
 
         case RRDSET_TYPE_STACKED:
-            return stacked;
+            return RRDSET_TYPE_STACKED_NAME;
     }
-    return line;
 }
 
 // ----------------------------------------------------------------------------
 // load / save
 
-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;
-
+inline const char *rrd_memory_mode_name(RRD_MEMORY_MODE id) {
     switch(id) {
         case RRD_MEMORY_MODE_RAM:
-            return ram;
+            return RRD_MEMORY_MODE_RAM_NAME;
 
         case RRD_MEMORY_MODE_MAP:
-            return map;
+            return RRD_MEMORY_MODE_MAP_NAME;
 
         case RRD_MEMORY_MODE_SAVE:
         default:
-            return save;
+            return RRD_MEMORY_MODE_SAVE_NAME;
     }
-
-    return save;
 }
 
 int rrd_memory_mode_id(const char *name)
@@ -300,36 +291,40 @@ int rrd_memory_mode_id(const char *name)
 // ----------------------------------------------------------------------------
 // algorithms types
 
-int rrddim_algorithm_id(const char *name)
+RRDDIM_ALGORITHM 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_ALGORITHM_INCREMENTAL_NAME) == 0)
+        return RRDDIM_ALGORITHM_INCREMENTAL;
+
+    else if(strcmp(name, RRDDIM_ALGORITHM_ABSOLUTE_NAME) == 0)
+        return RRDDIM_ALGORITHM_ABSOLUTE;
+
+    else if(strcmp(name, RRDDIM_ALGORITHM_PCENT_OVER_ROW_TOTAL_NAME) == 0)
+        return RRDDIM_ALGORITHM_PCENT_OVER_ROW_TOTAL;
+
+    else if(strcmp(name, RRDDIM_ALGORITHM_PCENT_OVER_DIFF_TOTAL_NAME) == 0)
+        return RRDDIM_ALGORITHM_PCENT_OVER_DIFF_TOTAL;
+
+    else
+        return RRDDIM_ALGORITHM_ABSOLUTE;
 }
 
-const char *rrddim_algorithm_name(int chart_type)
+const char *rrddim_algorithm_name(RRDDIM_ALGORITHM algorithm)
 {
-    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(algorithm) {
+        case RRDDIM_ALGORITHM_ABSOLUTE:
+        default:
+            return RRDDIM_ALGORITHM_ABSOLUTE_NAME;
 
-        case RRDDIM_INCREMENTAL:
-            return incremental;
+        case RRDDIM_ALGORITHM_INCREMENTAL:
+            return RRDDIM_ALGORITHM_INCREMENTAL_NAME;
 
-        case RRDDIM_PCENT_OVER_ROW_TOTAL:
-            return percentage_of_absolute_row;
+        case RRDDIM_ALGORITHM_PCENT_OVER_ROW_TOTAL:
+            return RRDDIM_ALGORITHM_PCENT_OVER_ROW_TOTAL_NAME;
 
-        case RRDDIM_PCENT_OVER_DIFF_TOTAL:
-            return percentage_of_incremental_row;
+        case RRDDIM_ALGORITHM_PCENT_OVER_DIFF_TOTAL:
+            return RRDDIM_ALGORITHM_PCENT_OVER_DIFF_TOTAL_NAME;
     }
-    return absolute;
 }
 
 // ----------------------------------------------------------------------------
@@ -353,22 +348,36 @@ char *rrdset_strncpyz_name(char *to, const char *from, size_t length)
 
 void rrdset_set_name(RRDSET *st, const char *name)
 {
-    debug(D_RRD_CALLS, "rrdset_set_name() old: %s, new: %s", st->name, name);
+    if(unlikely(st->name && !strcmp(st->name, name)))
+        return;
 
-    if(st->name) {
-        rrdset_index_del_name(&localhost, st);
-        rrdsetvar_rename_all(st);
-    }
+    debug(D_RRD_CALLS, "rrdset_set_name() old: %s, new: %s", st->name, name);
 
     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_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(&localhost, st);
+    if(st->name) {
+        rrdset_index_del_name(st->rrdhost, st);
+        st->name = config_set_default(st->id, "name", b);
+        st->hash_name = simple_hash(st->name);
+        rrdsetvar_rename_all(st);
+    }
+    else {
+        st->name = config_get(st->id, "name", b);
+        st->hash_name = simple_hash(st->name);
+    }
+
+    pthread_rwlock_wrlock(&st->rwlock);
+    RRDDIM *rd;
+    for(rd = st->dimensions; rd ;rd = rd->next)
+        rrddimvar_rename_all(rd);
+    pthread_rwlock_unlock(&st->rwlock);
+
+    if(unlikely(rrdset_index_add_name(st->rrdhost, st) != st))
+        error("RRDSET: INTERNAL ERROR: attempted to index duplicate chart name '%s'", st->name);
 }
 
 // ----------------------------------------------------------------------------
@@ -378,19 +387,11 @@ 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);
-        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);
+    snprintfz(n, FILENAME_MAX, "%s/%s", netdata_configured_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) {
@@ -422,12 +423,39 @@ void rrdset_reset(RRDSET *st)
         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));
+        memset(rd->values, 0, rd->entries * sizeof(storage_number));
     }
 }
+static inline long align_entries_to_pagesize(long entries) {
+    if(entries < 5) entries = 5;
+    if(entries > RRD_HISTORY_ENTRIES_MAX) entries = RRD_HISTORY_ENTRIES_MAX;
+
+#ifdef NETDATA_LOG_ALLOCATIONS
+    long page = (size_t)sysconf(_SC_PAGESIZE);
+
+    long size = sizeof(RRDDIM) + entries * sizeof(storage_number);
+    if(size % page) {
+        size -= (size % page);
+        size += page;
+
+        long n = (size - sizeof(RRDDIM)) / sizeof(storage_number);
+        return n;
+    }
+
+    return entries;
+#else
+    return entries;
+#endif
+}
+
+static inline void timeval_align(struct timeval *tv, int update_every) {
+    tv->tv_sec -= tv->tv_sec % update_every;
+    tv->tv_usec = 500000;
+}
+
+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) {
+    RRDHOST *host = &localhost;
 
-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;
@@ -440,19 +468,18 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
 
     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);
+    RRDSET *st = rrdset_find(host, fullid);
     if(st) {
-        error("Cannot create rrd stats for '%s', it already exists.", fullid);
+        debug(D_RRD_CALLS, "RRDSET '%s', 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);
+    long rentries = config_get_number(fullid, "history", rrd_default_history_entries);
+    long entries = align_entries_to_pagesize(rentries);
+    if(entries != rentries) entries = config_set_number(fullid, "history", entries);
 
     int enabled = config_get_boolean(fullid, "enabled", 1);
     if(!enabled) entries = 5;
@@ -468,30 +495,34 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
         if(strcmp(st->magic, RRDSET_MAGIC) != 0) {
             errno = 0;
             info("Initializing file %s.", fullfilename);
-            bzero(st, size);
+            memset(st, 0, 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);
+            memset(st, 0, 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);
+            memset(st, 0, 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);
+            memset(st, 0, size);
         }
-        else if((time(NULL) - st->last_updated.tv_sec) > update_every * entries) {
+        else if((now_realtime_sec() - st->last_updated.tv_sec) > update_every * entries) {
             errno = 0;
             error("File %s is too old. Clearing it.", fullfilename);
-            bzero(st, size);
+            memset(st, 0, size);
         }
+
+        // make sure the database is aligned
+        if(st->last_updated.tv_sec)
+            timeval_align(&st->last_updated, update_every);
     }
 
     if(st) {
@@ -506,12 +537,18 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
         st->mapped = rrd_memory_mode;
         st->variables = NULL;
         st->alarms = NULL;
+        memset(&st->rwlock, 0, sizeof(pthread_rwlock_t));
+        memset(&st->avl, 0, sizeof(avl));
+        memset(&st->avlname, 0, sizeof(avl));
+        memset(&st->variables_root_index, 0, sizeof(avl_tree_lock));
+        memset(&st->dimensions_index, 0, sizeof(avl_tree_lock));
     }
     else {
         st = callocz(1, size);
         st->mapped = RRD_MEMORY_MODE_RAM;
     }
 
+    st->rrdhost = host;
     st->memsize = size;
     st->entries = entries;
     st->update_every = update_every;
@@ -560,22 +597,23 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
     avl_init_lock(&st->variables_root_index, rrdvar_compare);
 
     pthread_rwlock_init(&st->rwlock, NULL);
-    rrdhost_rwlock(&localhost);
+    rrdhost_rwlock(host);
 
     if(name && *name) rrdset_set_name(st, name);
     else rrdset_set_name(st, id);
 
     {
         char varvalue[CONFIG_MAX_VALUE + 1];
+        char varvalue2[CONFIG_MAX_VALUE + 1];
         snprintfz(varvalue, CONFIG_MAX_VALUE, "%s (%s)", title?title:"", st->name);
-        st->title = config_get(st->id, "title", varvalue);
+        json_escape_string(varvalue2, varvalue, sizeof(varvalue2));
+        st->title = config_get(st->id, "title", varvalue2);
     }
 
-    st->rrdfamily = rrdfamily_create(st->family);
-    st->rrdhost = &localhost;
+    st->rrdfamily = rrdfamily_create(host, st->family);
 
-    st->next = localhost.rrdset_root;
-    localhost.rrdset_root = st;
+    st->next = host->rrdset_root;
+    host->rrdset_root = st;
 
     if(health_enabled) {
         rrdsetvar_create(st, "last_collected_t", RRDVAR_TYPE_TIME_T, &st->last_collected_time.tv_sec, 0);
@@ -585,101 +623,110 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
         rrdsetvar_create(st, "update_every", RRDVAR_TYPE_INT, &st->update_every, 0);
     }
 
-    rrdset_index_add(&localhost, st);
+    if(unlikely(rrdset_index_add(host, st) != st))
+        error("RRDSET: INTERNAL ERROR: attempt to index duplicate chart '%s'", st->id);
 
     rrdsetcalc_link_matching(st);
     rrdcalctemplate_link_matching(st);
 
-    rrdhost_unlock(&localhost);
+    rrdhost_unlock(host);
 
     return(st);
 }
 
-RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, long multiplier, long divisor, int algorithm)
+RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, collected_number multiplier, collected_number divisor, RRDDIM_ALGORITHM algorithm)
 {
+    RRDDIM *rd = rrddim_find(st, id);
+    if(rd) {
+        debug(D_RRD_CALLS, "Cannot create rrd dimension '%s/%s', it already exists.", st->id, name?name:"<NONAME>");
+        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(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) {
+            // we have a file mapped for rd
+
+            rd->id = NULL;
+            rd->name = NULL;
+            rd->cache_filename = NULL;
+            rd->memory_mode = rrd_memory_mode;
+            rd->flags = 0x00000000;
+            rd->variables = NULL;
+            rd->next = NULL;
+            rd->rrdset = NULL;
+            memset(&rd->avl, 0, sizeof(avl));
+
+            struct timeval now;
+            now_realtime_timeval(&now);
+
+            if(strcmp(rd->magic, RRDDIMENSION_MAGIC) != 0) {
+                errno = 0;
+                info("Initializing file %s.", fullfilename);
+                memset(rd, 0, size);
+            }
+            else if(rd->memsize != size) {
+                errno = 0;
+                error("File %s does not have the desired size. Clearing it.", fullfilename);
+                memset(rd, 0, size);
+            }
+            else if(rd->multiplier != multiplier) {
+                errno = 0;
+                error("File %s does not have the same multiplier. Clearing it.", fullfilename);
+                memset(rd, 0, size);
+            }
+            else if(rd->divisor != divisor) {
+                errno = 0;
+                error("File %s does not have the same divisor. Clearing it.", fullfilename);
+                memset(rd, 0, size);
+            }
+            else if(rd->update_every != st->update_every) {
+                errno = 0;
+                error("File %s does not have the same refresh frequency. Clearing it.", fullfilename);
+                memset(rd, 0, size);
+            }
+            else if(dt_usec(&now, &rd->last_collected_time) > (rd->entries * rd->update_every * USEC_PER_SEC)) {
+                errno = 0;
+                error("File %s is too old. Clearing it.", fullfilename);
+                memset(rd, 0, size);
+            }
+
+            if(rd->algorithm && rd->algorithm != algorithm)
+                error("File %s does not have the expected algorithm (expected %u '%s', found %u '%s'). Previous values may be wrong."
+                      , fullfilename, algorithm, rrddim_algorithm_name(algorithm), rd->algorithm,
+                        rrddim_algorithm_name(rd->algorithm));
         }
     }
 
-    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(unlikely(!rd)) {
         // 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->memory_mode = 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->id = strdupz(id);
     rd->hash = simple_hash(rd->id);
 
+    rd->cache_filename = strdupz(fullfilename);
+
     snprintfz(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
     rd->name = config_get(st->id, varname, (name && *name)?name:rd->id);
+    rd->hash_name = simple_hash(rd->name);
 
     snprintfz(varname, CONFIG_MAX_NAME, "dim %s algorithm", rd->id);
     rd->algorithm = rrddim_algorithm_id(config_get(st->id, varname, rrddim_algorithm_name(algorithm)));
@@ -696,7 +743,7 @@ RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, long multiplier
 
     // prevent incremental calculation spikes
     rd->counter = 0;
-    rd->updated = 0;
+    rrddim_flag_clear(rd, RRDDIM_FLAG_UPDATED);
     rd->calculated_value = 0;
     rd->last_calculated_value = 0;
     rd->collected_value = 0;
@@ -727,18 +774,23 @@ RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, long multiplier
 
     pthread_rwlock_unlock(&st->rwlock);
 
-    rrddim_index_add(st, rd);
+    if(unlikely(rrddim_index_add(st, rd) != rd))
+        error("RRDDIM: INTERNAL ERROR: attempt to index duplicate dimension '%s' on chart '%s'", rd->id, st->id);
 
     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);
+    if(unlikely(!strcmp(rd->name, name)))
+        return;
+
+    debug(D_RRD_CALLS, "rrddim_set_name() from %s.%s to %s.%s", st->name, rd->name, st->name, name);
 
     char varname[CONFIG_MAX_NAME + 1];
     snprintfz(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
-    config_set_default(st->id, varname, name);
+    rd->name = config_set_default(st->id, varname, name);
+    rd->hash_name = simple_hash(rd->name);
 
     rrddimvar_rename_all(rd);
 }
@@ -763,23 +815,30 @@ void rrddim_free(RRDSET *st, RRDDIM *rd)
     while(rd->variables)
         rrddimvar_free(rd->variables);
 
-    rrddim_index_del(st, rd);
+    if(unlikely(rrddim_index_del(st, rd) != rd))
+        error("RRDDIM: INTERNAL ERROR: attempt to remove from index dimension '%s' on chart '%s', removed a different dimension.", rd->id, st->id);
 
     // 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);
+    switch(rd->memory_mode) {
+        case 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);
+            // continue to map mode - no break;
+
+        case RRD_MEMORY_MODE_MAP:
+            debug(D_RRD_CALLS, "Unmapping dimension '%s'.", rd->name);
+            freez((void *)rd->id);
+            freez(rd->cache_filename);
+            munmap(rd, rd->memsize);
+            break;
+
+        case RRD_MEMORY_MODE_RAM:
+            debug(D_RRD_CALLS, "Removing dimension '%s'.", rd->name);
+            freez((void *)rd->id);
+            freez(rd->cache_filename);
+            freez(rd);
+            break;
     }
 }
 
@@ -804,22 +863,18 @@ void rrdset_free_all(void)
         while(st->dimensions)
             rrddim_free(st, st->dimensions);
 
-        rrdset_index_del(&localhost, st);
+        if(unlikely(rrdset_index_del(&localhost, st) != st))
+            error("RRDSET: INTERNAL ERROR: attempt to remove from index chart '%s', removed a different chart.", st->id);
+
+        rrdset_index_del_name(&localhost, st);
 
         st->rrdfamily->use_count--;
         if(!st->rrdfamily->use_count)
-            rrdfamily_free(st->rrdfamily);
+            rrdfamily_free(&localhost, 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) {
+        if(st->mapped == RRD_MEMORY_MODE_SAVE || st->mapped == RRD_MEMORY_MODE_MAP) {
             debug(D_RRD_CALLS, "Unmapping stats '%s'.", st->name);
             munmap(st, st->memsize);
         }
@@ -841,9 +896,12 @@ void rrdset_save_all(void) {
     RRDSET *st;
     RRDDIM *rd;
 
+    // we get an write lock
+    // to ensure only one thread is saving the database
     rrdhost_rwlock(&localhost);
+
     for(st = localhost.rrdset_root; st ; st = st->next) {
-        pthread_rwlock_wrlock(&st->rwlock);
+        pthread_rwlock_rdlock(&st->rwlock);
 
         if(st->mapped == RRD_MEMORY_MODE_SAVE) {
             debug(D_RRD_CALLS, "Saving stats '%s' to '%s'.", st->name, st->cache_filename);
@@ -851,7 +909,7 @@ void rrdset_save_all(void) {
         }
 
         for(rd = st->dimensions; rd ; rd = rd->next) {
-            if(likely(rd->mapped == RRD_MEMORY_MODE_SAVE)) {
+            if(likely(rd->memory_mode == 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);
             }
@@ -859,37 +917,33 @@ void rrdset_save_all(void) {
 
         pthread_rwlock_unlock(&st->rwlock);
     }
+
     rrdhost_unlock(&localhost);
 }
 
 
-RRDSET *rrdset_find(const char *id)
-{
-    debug(D_RRD_CALLS, "rrdset_find() for chart %s", id);
-
-    RRDSET *st = rrdset_index_find(&localhost, id, 0);
+RRDSET *rrdset_find(RRDHOST *host, const char *id) {
+    debug(D_RRD_CALLS, "rrdset_find() for chart '%s' in host '%s'", id, host->hostname);
+    RRDSET *st = rrdset_index_find(host, id, 0);
     return(st);
 }
 
-RRDSET *rrdset_find_bytype(const char *type, const char *id)
+RRDSET *rrdset_find_bytype(RRDHOST *host, 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' in host '%s'", type, id, host->hostname);
 
     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));
 
-    return(rrdset_find(buf));
+    return(rrdset_find(host, buf));
 }
 
-RRDSET *rrdset_find_byname(const char *name)
-{
-    debug(D_RRD_CALLS, "rrdset_find_byname() for chart %s", name);
-
-    RRDSET *st = rrdset_index_find_name(&localhost, name, 0);
+RRDSET *rrdset_find_byname(RRDHOST *host, const char *name) {
+    debug(D_RRD_CALLS, "rrdset_find_byname() for chart '%s' in host '%s'", name, host->hostname);
+    RRDSET *st = rrdset_index_find_name(host, name, 0);
     return(st);
 }
 
@@ -910,12 +964,11 @@ int rrddim_hide(RRDSET *st, const char *id)
         return 1;
     }
 
-    rd->flags |= RRDDIM_FLAG_HIDDEN;
+    rrddim_flag_set(rd, RRDDIM_FLAG_HIDDEN);
     return 0;
 }
 
-int rrddim_unhide(RRDSET *st, const char *id)
-{
+int rrddim_unhide(RRDSET *st, const char *id) {
     debug(D_RRD_CALLS, "rrddim_unhide() for chart %s, dimension %s", st->name, id);
 
     RRDDIM *rd = rrddim_find(st, id);
@@ -924,7 +977,7 @@ int rrddim_unhide(RRDSET *st, const char *id)
         return 1;
     }
 
-    if(rd->flags & RRDDIM_FLAG_HIDDEN) rd->flags ^= RRDDIM_FLAG_HIDDEN;
+    rrddim_flag_clear(rd, RRDDIM_FLAG_HIDDEN);
     return 0;
 }
 
@@ -932,9 +985,9 @@ collected_number rrddim_set_by_pointer(RRDSET *st, RRDDIM *rd, collected_number
 {
     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);
+    now_realtime_timeval(&rd->last_collected_time);
     rd->collected_value = value;
-    rd->updated = 1;
+    rrddim_flag_set(rd, RRDDIM_FLAG_UPDATED);
     rd->counter++;
 
     // fprintf(stderr, "%s.%s %llu " COLLECTED_NUMBER_FORMAT " dt %0.6f" " rate " CALCULATED_NUMBER_FORMAT "\n", st->name, rd->name, st->usec_since_last_update, value, (float)((double)st->usec_since_last_update / (double)1000000), (calculated_number)((value - rd->last_collected_value) * (calculated_number)rd->multiplier / (calculated_number)rd->divisor * 1000000.0 / (calculated_number)st->usec_since_last_update));
@@ -953,38 +1006,63 @@ collected_number rrddim_set(RRDSET *st, const char *id, collected_number value)
     return rrddim_set_by_pointer(st, rd, value);
 }
 
-void rrdset_next_usec(RRDSET *st, unsigned long long microseconds)
+void rrdset_next_usec_unfiltered(RRDSET *st, usec_t 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->last_collected_time.tv_sec || !microseconds)) {
+        // the first entry
+        microseconds = st->update_every * USEC_PER_SEC;
     }
+    st->usec_since_last_update = microseconds;
 }
 
-void rrdset_next(RRDSET *st)
+void rrdset_next_usec(RRDSET *st, usec_t microseconds)
 {
-    unsigned long long microseconds = 0;
+    struct timeval now;
+    now_realtime_timeval(&now);
 
-    if(likely(st->last_collected_time.tv_sec)) {
-        struct timeval now;
-        gettimeofday(&now, NULL);
-        microseconds = usec_dt(&now, &st->last_collected_time);
+    if(unlikely(!st->last_collected_time.tv_sec)) {
+        // the first entry
+        microseconds = st->update_every * USEC_PER_SEC;
+    }
+    else if(unlikely(!microseconds)) {
+        // no dt given by the plugin
+        microseconds = dt_usec(&now, &st->last_collected_time);
     }
-    // prevent infinite loop
-    else microseconds = st->update_every * 1000000ULL;
+    else {
+        // microseconds has the time since the last collection
+#ifdef NETDATA_INTERNAL_CHECKS
+        usec_t now_usec = timeval_usec(&now);
+        usec_t last_usec = timeval_usec(&st->last_collected_time);
+#endif
+        usec_t since_last_usec = dt_usec(&now, &st->last_collected_time);
 
-    rrdset_next_usec(st, microseconds);
-}
+        // verify the microseconds given is good
+        if(unlikely(microseconds > since_last_usec)) {
+            debug(D_RRD_CALLS, "dt %llu usec given is too big - it leads %llu usec to the future, for chart '%s' (%s).", microseconds, microseconds - since_last_usec, st->name, st->id);
 
-void rrdset_next_plugins(RRDSET *st)
-{
-    rrdset_next(st);
+#ifdef NETDATA_INTERNAL_CHECKS
+            if(unlikely(last_usec + microseconds > now_usec + 1000))
+                error("dt %llu usec given is too big - it leads %llu usec to the future, for chart '%s' (%s).", microseconds, microseconds - since_last_usec, st->name, st->id);
+#endif
+
+            microseconds = since_last_usec;
+        }
+        else if(unlikely(microseconds < since_last_usec * 0.8)) {
+            debug(D_RRD_CALLS, "dt %llu usec given is too small - expected %llu usec up to -20%%, for chart '%s' (%s).", microseconds, since_last_usec, st->name, st->id);
+
+#ifdef NETDATA_INTERNAL_CHECKS
+            error("dt %llu usec given is too small - expected %llu usec up to -20%%, for chart '%s' (%s).", microseconds, since_last_usec, st->name, st->id);
+#endif
+            microseconds = since_last_usec;
+        }
+    }
+    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;
 }
 
-unsigned long long rrdset_done(RRDSET *st)
+usec_t rrdset_done(RRDSET *st)
 {
     if(unlikely(netdata_exit)) return 0;
 
@@ -1002,12 +1080,12 @@ unsigned long long rrdset_done(RRDSET *st)
     unsigned int
         stored_entries = 0;     // the number of entries we have stored in the db, during this call to rrdset_done()
 
-    unsigned long long
+    usec_t
         last_collect_ut,        // the timestamp in microseconds, of the last collected value
         now_collect_ut,         // the timestamp in microseconds, of this collected value (this is NOW)
         last_stored_ut,         // the timestamp in microseconds, of the last stored entry in the db
         next_store_ut,          // the timestamp in microseconds, of the next entry to store in the db
-        update_every_ut = st->update_every * 1000000ULL; // st->update_every in microseconds
+        update_every_ut = st->update_every * USEC_PER_SEC; // st->update_every in microseconds
 
     if(unlikely(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &pthreadoldcancelstate) != 0))
         error("Cannot set pthread cancel state to DISABLE.");
@@ -1023,7 +1101,7 @@ unsigned long long rrdset_done(RRDSET *st)
 
     // check if the chart has a long time to be updated
     if(unlikely(st->usec_since_last_update > st->entries * update_every_ut)) {
-        info("%s: took too long to be updated (%0.3Lf secs). Reseting it.", st->name, (long double)(st->usec_since_last_update / 1000000.0));
+        info("%s: took too long to be updated (%0.3Lf secs). Resetting it.", st->name, (long double)(st->usec_since_last_update / 1000000.0));
         rrdset_reset(st);
         st->usec_since_last_update = update_every_ut;
         first_entry = 1;
@@ -1034,8 +1112,10 @@ unsigned long long rrdset_done(RRDSET *st)
     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);
-        last_collect_ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec - update_every_ut;
+        now_realtime_timeval(&st->last_collected_time);
+        timeval_align(&st->last_collected_time, st->update_every);
+
+        last_collect_ut = st->last_collected_time.tv_sec * USEC_PER_SEC + st->last_collected_time.tv_usec - update_every_ut;
 
         // the first entry should not be stored
         store_this_entry = 0;
@@ -1046,10 +1126,10 @@ unsigned long long rrdset_done(RRDSET *st)
     else {
         // it is not the first entry
         // calculate the proper last_collected_time, using usec_since_last_update
-        last_collect_ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec;
-        unsigned long long ut = last_collect_ut + 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);
+        last_collect_ut = st->last_collected_time.tv_sec * USEC_PER_SEC + st->last_collected_time.tv_usec;
+        usec_t ut = last_collect_ut + st->usec_since_last_update;
+        st->last_collected_time.tv_sec = (time_t) (ut / USEC_PER_SEC);
+        st->last_collected_time.tv_usec = (suseconds_t) (ut % USEC_PER_SEC);
     }
 
     // if this set has not been updated in the past
@@ -1057,9 +1137,9 @@ unsigned long long rrdset_done(RRDSET *st)
     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);
+        usec_t ut = st->last_collected_time.tv_sec * USEC_PER_SEC + st->last_collected_time.tv_usec - st->usec_since_last_update;
+        st->last_updated.tv_sec = (time_t) (ut / USEC_PER_SEC);
+        st->last_updated.tv_usec = (suseconds_t) (ut % USEC_PER_SEC);
 
         // the first entry should not be stored
         store_this_entry = 0;
@@ -1069,17 +1149,18 @@ unsigned long long rrdset_done(RRDSET *st)
     }
 
     // check if we will re-write the entire data set
-    if(unlikely(usec_dt(&st->last_collected_time, &st->last_updated) > st->entries * update_every_ut)) {
-        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);
+    if(unlikely(dt_usec(&st->last_collected_time, &st->last_updated) > st->entries * update_every_ut)) {
+        info("%s: too old data (last updated at %ld.%ld, last collected at %ld.%ld). Resetting 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 = update_every_ut;
 
-        gettimeofday(&st->last_collected_time, NULL);
+        now_realtime_timeval(&st->last_collected_time);
+        timeval_align(&st->last_collected_time, st->update_every);
 
-        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);
+        usec_t ut = st->last_collected_time.tv_sec * USEC_PER_SEC + st->last_collected_time.tv_usec - st->usec_since_last_update;
+        st->last_updated.tv_sec = (time_t) (ut / USEC_PER_SEC);
+        st->last_updated.tv_usec = (suseconds_t) (ut % USEC_PER_SEC);
 
         // the first entry should not be stored
         store_this_entry = 0;
@@ -1090,9 +1171,9 @@ unsigned long long rrdset_done(RRDSET *st)
     // last_stored_ut = the last time we added a value to the storage
     // now_collect_ut = the time the current value has been collected
     // next_store_ut  = the time of the next interpolation point
-    last_stored_ut = st->last_updated.tv_sec * 1000000ULL + st->last_updated.tv_usec;
-    now_collect_ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec;
-    next_store_ut  = (st->last_updated.tv_sec + st->update_every) * 1000000ULL;
+    last_stored_ut = st->last_updated.tv_sec * USEC_PER_SEC + st->last_updated.tv_usec;
+    now_collect_ut = st->last_collected_time.tv_sec * USEC_PER_SEC + st->last_collected_time.tv_usec;
+    next_store_ut  = (st->last_updated.tv_sec + st->update_every) * USEC_PER_SEC;
 
     if(unlikely(st->debug)) {
         debug(D_RRD_STATS, "%s: last_collect_ut = %0.3Lf (last collection time)", st->name, (long double)last_collect_ut/1000000.0);
@@ -1111,7 +1192,8 @@ unsigned long long rrdset_done(RRDSET *st)
     int dimensions;
     st->collected_total = 0;
     for( rd = st->dimensions, dimensions = 0 ; rd ; rd = rd->next, dimensions++ )
-        if(likely(rd->updated)) st->collected_total += rd->collected_value;
+        if(likely(rrddim_flag_check(rd, RRDDIM_FLAG_UPDATED)))
+            st->collected_total += rd->collected_value;
 
     uint32_t storage_flags = SN_EXISTS;
 
@@ -1120,7 +1202,7 @@ unsigned long long rrdset_done(RRDSET *st)
     // at this stage we do not interpolate anything
     for( rd = st->dimensions ; rd ; rd = rd->next ) {
 
-        if(unlikely(!rd->updated)) {
+        if(unlikely(!rrddim_flag_check(rd, RRDDIM_FLAG_UPDATED))) {
             rd->calculated_value = 0;
             continue;
         }
@@ -1138,7 +1220,7 @@ unsigned long long rrdset_done(RRDSET *st)
             );
 
         switch(rd->algorithm) {
-            case RRDDIM_ABSOLUTE:
+            case RRDDIM_ALGORITHM_ABSOLUTE:
                 rd->calculated_value = (calculated_number)rd->collected_value
                     * (calculated_number)rd->multiplier
                     / (calculated_number)rd->divisor;
@@ -1157,7 +1239,7 @@ unsigned long long rrdset_done(RRDSET *st)
                         );
                 break;
 
-            case RRDDIM_PCENT_OVER_ROW_TOTAL:
+            case RRDDIM_ALGORITHM_PCENT_OVER_ROW_TOTAL:
                 if(unlikely(!st->collected_total))
                     rd->calculated_value = 0;
                 else
@@ -1180,7 +1262,7 @@ unsigned long long rrdset_done(RRDSET *st)
                         );
                 break;
 
-            case RRDDIM_INCREMENTAL:
+            case RRDDIM_ALGORITHM_INCREMENTAL:
                 if(unlikely(rd->counter <= 1)) {
                     rd->calculated_value = 0;
                     continue;
@@ -1193,7 +1275,10 @@ unsigned long long rrdset_done(RRDSET *st)
                             , 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;
+
+                    if(!(rrddim_flag_check(rd, RRDDIM_FLAG_DONT_DETECT_RESETS_OR_OVERFLOWS)))
+                        storage_flags = SN_EXISTS_RESET;
+
                     rd->last_collected_value = rd->collected_value;
                 }
 
@@ -1217,7 +1302,7 @@ unsigned long long rrdset_done(RRDSET *st)
                         );
                 break;
 
-            case RRDDIM_PCENT_OVER_DIFF_TOTAL:
+            case RRDDIM_ALGORITHM_PCENT_OVER_DIFF_TOTAL:
                 if(unlikely(rd->counter <= 1)) {
                     rd->calculated_value = 0;
                     continue;
@@ -1230,7 +1315,10 @@ unsigned long long rrdset_done(RRDSET *st)
                     , 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;
+
+                    if(!(rrddim_flag_check(rd, RRDDIM_FLAG_DONT_DETECT_RESETS_OR_OVERFLOWS)))
+                        storage_flags = SN_EXISTS_RESET;
+
                     rd->last_collected_value = rd->collected_value;
                 }
 
@@ -1290,9 +1378,12 @@ unsigned long long rrdset_done(RRDSET *st)
     if(unlikely(now_collect_ut < next_store_ut)) {
         // this is collected in the same interpolation point
         if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: THIS IS IN THE SAME INTERPOLATION POINT", st->name);
+#ifdef NETDATA_INTERNAL_CHECKS
+        info("%s is collected in the same interpolation point: short by %llu microseconds", st->name, next_store_ut - now_collect_ut);
+#endif
     }
 
-    unsigned long long first_ut = last_stored_ut;
+    usec_t first_ut = last_stored_ut;
     long long iterations = (now_collect_ut - last_stored_ut) / (update_every_ut);
     if((now_collect_ut % (update_every_ut)) == 0) iterations++;
 
@@ -1306,14 +1397,14 @@ unsigned long long rrdset_done(RRDSET *st)
             debug(D_RRD_STATS, "%s: next_store_ut  = %0.3Lf (next interpolation point)", st->name, (long double)next_store_ut/1000000.0);
         }
 
-        st->last_updated.tv_sec = (time_t) (next_store_ut / 1000000ULL);
+        st->last_updated.tv_sec = (time_t) (next_store_ut / USEC_PER_SEC);
         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:
+                case RRDDIM_ALGORITHM_INCREMENTAL:
                     new_value = (calculated_number)
                         (      rd->calculated_value
                             * (calculated_number)(next_store_ut - last_collect_ut)
@@ -1348,9 +1439,9 @@ unsigned long long rrdset_done(RRDSET *st)
                     }
                     break;
 
-                case RRDDIM_ABSOLUTE:
-                case RRDDIM_PCENT_OVER_ROW_TOTAL:
-                case RRDDIM_PCENT_OVER_DIFF_TOTAL:
+                case RRDDIM_ALGORITHM_ABSOLUTE:
+                case RRDDIM_ALGORITHM_PCENT_OVER_ROW_TOTAL:
+                case RRDDIM_ALGORITHM_PCENT_OVER_DIFF_TOTAL:
                 default:
                     if(iterations == 1) {
                         // this is the last iteration
@@ -1387,10 +1478,12 @@ unsigned long long rrdset_done(RRDSET *st)
                     break;
             }
 
-            if(unlikely(!store_this_entry))
+            if(unlikely(!store_this_entry)) {
+                rd->values[st->current_entry] = pack_storage_number(0, SN_NOT_EXISTS);
                 continue;
+            }
 
-            if(likely(rd->updated && rd->counter > 1 && iterations < st->gap_when_lost_iterations_above)) {
+            if(likely(rrddim_flag_check(rd, RRDDIM_FLAG_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;
 
@@ -1452,13 +1545,14 @@ unsigned long long rrdset_done(RRDSET *st)
     st->last_collected_total  = st->collected_total;
 
     for( rd = st->dimensions; rd ; rd = rd->next ) {
-        if(unlikely(!rd->updated)) continue;
+        if(unlikely(!rrddim_flag_check(rd, RRDDIM_FLAG_UPDATED)))
+            continue;
 
         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;
 
         switch(rd->algorithm) {
-            case RRDDIM_INCREMENTAL:
+            case RRDDIM_ALGORITHM_INCREMENTAL:
                 if(unlikely(!first_entry)) {
                     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->calculated_value);
                     rd->last_calculated_value += rd->calculated_value;
@@ -1468,9 +1562,9 @@ unsigned long long rrdset_done(RRDSET *st)
                 }
                 break;
 
-            case RRDDIM_ABSOLUTE:
-            case RRDDIM_PCENT_OVER_ROW_TOTAL:
-            case RRDDIM_PCENT_OVER_DIFF_TOTAL:
+            case RRDDIM_ALGORITHM_ABSOLUTE:
+            case RRDDIM_ALGORITHM_PCENT_OVER_ROW_TOTAL:
+            case RRDDIM_ALGORITHM_PCENT_OVER_DIFF_TOTAL:
                 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;
                 break;
@@ -1478,7 +1572,7 @@ unsigned long long rrdset_done(RRDSET *st)
 
         rd->calculated_value = 0;
         rd->collected_value = 0;
-        rd->updated = 0;
+        rrddim_flag_clear(rd, RRDDIM_FLAG_UPDATED);
 
         if(unlikely(st->debug)) debug(D_RRD_STATS, "%s/%s: END "
             " last_collected_value = " COLLECTED_NUMBER_FORMAT