]> arthur.barton.de Git - netdata.git/blobdiff - src/rrd.c
layout: remove executable from unrelated files
[netdata.git] / src / rrd.c
old mode 100755 (executable)
new mode 100644 (file)
index aabcd5c..2dce02e
--- a/src/rrd.c
+++ b/src/rrd.c
@@ -1,3 +1,6 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 #include <stddef.h>
 #include <string.h>
 #include <unistd.h>
@@ -11,9 +14,9 @@
 #include <sys/types.h>
 #include <stdlib.h>
 
-#include "log.h"
-#include "config.h"
 #include "common.h"
+#include "log.h"
+#include "appconfig.h"
 
 #include "rrd.h"
 
@@ -23,6 +26,8 @@
 // globals
 
 // if not zero it gives the time (in seconds) to remove un-updated dimensions
+// DO NOT ENABLE
+// if dimensions are removed, the chart generation will have to run again
 int rrd_delete_unupdated_dimensions = 0;
 
 int rrd_update_every = UPDATE_EVERY;
@@ -47,7 +52,12 @@ static int rrdset_compare(void* a, void* b) {
 
 avl_tree rrdset_root_index = {
                NULL,
-               rrdset_compare
+               rrdset_compare,
+#ifdef AVL_LOCK_WITH_MUTEX
+               PTHREAD_MUTEX_INITIALIZER
+#else
+               PTHREAD_RWLOCK_INITIALIZER
+#endif
 };
 
 #define rrdset_index_add(st) avl_insert(&rrdset_root_index, (avl *)(st))
@@ -83,7 +93,12 @@ static int rrdset_compare_name(void* a, void* b) {
 
 avl_tree rrdset_root_index_name = {
                NULL,
-               rrdset_compare_name
+               rrdset_compare_name,
+#ifdef AVL_LOCK_WITH_MUTEX
+               PTHREAD_MUTEX_INITIALIZER
+#else
+               PTHREAD_RWLOCK_INITIALIZER
+#endif
 };
 
 int rrdset_index_add_name(RRDSET *st) {
@@ -278,14 +293,14 @@ char *rrdset_cache_dir(const char *id)
        char *ret = NULL;
 
        static char *cache_dir = NULL;
-       if(!cache_dir) cache_dir = config_get("global", "database directory", "cache");
+       if(!cache_dir) cache_dir = config_get("global", "cache directory", CACHE_DIR);
 
        char b[FILENAME_MAX + 1];
        char n[FILENAME_MAX + 1];
        rrdset_strncpy_name(b, id, FILENAME_MAX);
 
        snprintf(n, FILENAME_MAX, "%s/%s", cache_dir, b);
-       ret = config_get(id, "database directory", n);
+       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);
@@ -315,12 +330,18 @@ void rrdset_reset(RRDSET *st)
        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 *title, const char *units, long priority, int update_every, int chart_type)
+RRDSET *rrdset_create(const char *type, const char *id, const char *name, const char *family, const char *context, const char *title, const char *units, long priority, int update_every, int chart_type)
 {
+       if(!type || !type[0]) {
+               fatal("Cannot create rrd stats without a type.");
+               return NULL;
+       }
+
        if(!id || !id[0]) {
                fatal("Cannot create rrd stats without an id.");
                return NULL;
@@ -332,6 +353,12 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
 
        snprintf(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);
@@ -345,7 +372,7 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
        debug(D_RRD_CALLS, "Creating RRD_STATS for '%s.%s'.", type, id);
 
        snprintf(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));
+       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;
@@ -380,6 +407,7 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
                st->name = NULL;
                st->type = NULL;
                st->family = NULL;
+               st->context = NULL;
                st->title = NULL;
                st->units = NULL;
                st->dimensions = NULL;
@@ -406,14 +434,15 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
 
        st->cache_dir = cache_dir;
 
-       st->family     = config_get(st->id, "family", family?family:st->id);
-       st->units      = config_get(st->id, "units", units?units:"");
-       st->type       = config_get(st->id, "type", type);
        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;
 
@@ -421,10 +450,10 @@ RRDSET *rrdset_create(const char *type, const char *id, const char *name, const
        st->last_collected_time.tv_usec = 0;
        st->counter_done = 0;
 
-       st->gap_when_lost_iterations_above = config_get_number(st->id, "gap when lost iterations above", RRD_DEFAULT_GAP_INTERPOLATIONS) + 2;
+       st->gap_when_lost_iterations_above = (int) (
+                       config_get_number(st->id, "gap when lost iterations above", RRD_DEFAULT_GAP_INTERPOLATIONS) + 2);
 
-       st->dimensions_index.root = NULL;
-       st->dimensions_index.compar = rrddim_compare;
+       avl_init(&st->dimensions_index, rrddim_compare);
 
        pthread_rwlock_init(&st->rwlock, NULL);
        pthread_rwlock_wrlock(&rrdset_root_rwlock);
@@ -461,7 +490,7 @@ RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, long multiplier
 
        rrdset_strncpy_name(filename, id, FILENAME_MAX);
        snprintf(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));
+       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);
@@ -513,7 +542,7 @@ RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, long multiplier
        if(rd) {
                // we have a file mapped for rd
                rd->mapped = rrd_memory_mode;
-               rd->hidden = 0;
+               rd->flags = 0x00000000;
                rd->next = NULL;
                rd->name = NULL;
        }
@@ -550,8 +579,12 @@ RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, long multiplier
 
        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 {
@@ -559,6 +592,7 @@ RRDDIM *rrddim_add(RRDSET *st, const char *id, const char *name, long multiplier
                for(; td->next; td = td->next) ;
                td->next = rd;
        }
+       pthread_rwlock_unlock(&st->rwlock);
 
        rrddim_index_add(st, rd);
 
@@ -571,14 +605,14 @@ void rrddim_set_name(RRDSET *st, RRDDIM *rd, const char *name)
 
        char varname[CONFIG_MAX_NAME + 1];
        snprintf(varname, CONFIG_MAX_NAME, "dim %s name", rd->id);
-       config_get(st->id, varname, name);
+       config_set_default(st->id, varname, name);
 }
 
 void rrddim_free(RRDSET *st, RRDDIM *rd)
 {
        debug(D_RRD_CALLS, "rrddim_free() %s.%s", st->name, rd->name);
 
-       RRDDIM *i = st->dimensions, *last = NULL;
+       RRDDIM *i, *last = NULL;
        for(i = st->dimensions; i && i != rd ; i = i->next) last = i;
 
        if(!i) {
@@ -586,8 +620,9 @@ void rrddim_free(RRDSET *st, RRDDIM *rd)
                return;
        }
 
-       if(last) last = i->next;
-       else st->dimensions = i->next;
+       if(last) last->next = rd->next;
+       else st->dimensions = rd->next;
+       rd->next = NULL;
 
        rrddim_index_del(st, rd);
 
@@ -676,10 +711,7 @@ RRDSET *rrdset_find(const char *id)
 {
        debug(D_RRD_CALLS, "rrdset_find() for chart %s", id);
 
-       pthread_rwlock_rdlock(&rrdset_root_rwlock);
        RRDSET *st = rrdset_index_find(id, 0);
-       pthread_rwlock_unlock(&rrdset_root_rwlock);
-
        return(st);
 }
 
@@ -692,8 +724,8 @@ RRDSET *rrdset_find_bytype(const char *type, const char *id)
        strncpy(buf, type, RRD_ID_LENGTH_MAX - 1);
        buf[RRD_ID_LENGTH_MAX - 1] = '\0';
        strcat(buf, ".");
-       int len = strlen(buf);
-       strncpy(&buf[len], id, RRD_ID_LENGTH_MAX - len);
+       int len = (int) strlen(buf);
+       strncpy(&buf[len], id, (size_t) (RRD_ID_LENGTH_MAX - len));
        buf[RRD_ID_LENGTH_MAX] = '\0';
 
        return(rrdset_find(buf));
@@ -703,10 +735,7 @@ RRDSET *rrdset_find_byname(const char *name)
 {
        debug(D_RRD_CALLS, "rrdset_find_byname() for chart %s", name);
 
-       pthread_rwlock_rdlock(&rrdset_root_rwlock);
        RRDSET *st = rrdset_index_find_name(name, 0);
-       pthread_rwlock_unlock(&rrdset_root_rwlock);
-
        return(st);
 }
 
@@ -727,7 +756,7 @@ int rrddim_hide(RRDSET *st, const char *id)
                return 1;
        }
 
-       rd->hidden = 1;
+       rd->flags |= RRDDIM_FLAG_HIDDEN;
        return 0;
 }
 
@@ -741,17 +770,18 @@ int rrddim_unhide(RRDSET *st, const char *id)
                return 1;
        }
 
-       rd->hidden = 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);
-       
+
        gettimeofday(&rd->last_collected_time, NULL);
        rd->collected_value = value;
        rd->updated = 1;
+       rd->counter++;
 
        return rd->last_collected_value;
 }
@@ -787,6 +817,8 @@ void rrdset_next(RRDSET *st)
                gettimeofday(&now, NULL);
                microseconds = usecdiff(&now, &st->last_collected_time);
        }
+       // prevent infinite loop
+       else microseconds = st->update_every * 1000000ULL;
 
        rrdset_next_usec(st, microseconds);
 }
@@ -801,7 +833,8 @@ 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;
+       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.");
@@ -809,11 +842,15 @@ unsigned long long rrdset_done(RRDSET *st)
        // a read lock is OK here
        pthread_rwlock_rdlock(&st->rwlock);
 
-       // check if the chart has a long time to be refreshed
+       // enable the chart, if it was disabled
+       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);
 
@@ -825,15 +862,16 @@ unsigned long long rrdset_done(RRDSET *st)
 
                // 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_collected to now. Will not store the next entry.", st->name);
+               if(unlikely(st->debug)) debug(D_RRD_STATS, "%s: has not set last_collected_time. Setting it now. Will not store the next entry.", st->name);
        }
        else {
                // it is not the first entry
                // calculate the proper last_collected_time, using usec_since_last_update
                unsigned long long ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec + st->usec_since_last_update;
-               st->last_collected_time.tv_sec = ut / 1000000ULL;
-               st->last_collected_time.tv_usec = ut % 1000000ULL;
+               st->last_collected_time.tv_sec = (time_t) (ut / 1000000ULL);
+               st->last_collected_time.tv_usec = (useconds_t) (ut % 1000000ULL);
        }
 
        // if this set has not been updated in the past
@@ -842,11 +880,12 @@ unsigned long long rrdset_done(RRDSET *st)
                // it has never been updated before
                // set a fake last_updated, in the past using usec_since_last_update
                unsigned long long ut = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec - st->usec_since_last_update;
-               st->last_updated.tv_sec = ut / 1000000ULL;
-               st->last_updated.tv_usec = ut % 1000000ULL;
+               st->last_updated.tv_sec = (time_t) (ut / 1000000ULL);
+               st->last_updated.tv_usec = (useconds_t) (ut % 1000000ULL);
 
                // the first entry should not be stored
                store_this_entry = 0;
+               first_entry = 1;
 
                if(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);
        }
@@ -861,20 +900,25 @@ unsigned long long rrdset_done(RRDSET *st)
                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 = ut / 1000000ULL;
-               st->last_updated.tv_usec = ut % 1000000ULL;
+               st->last_updated.tv_sec = (time_t) (ut / 1000000ULL);
+               st->last_updated.tv_usec = (useconds_t) (ut % 1000000ULL);
 
                // the first entry should not be stored
                store_this_entry = 0;
+               first_entry = 1;
        }
 
        // 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
-       unsigned long long last_ut = st->last_updated.tv_sec * 1000000ULL + st->last_updated.tv_usec;
-       unsigned long long now_ut  = st->last_collected_time.tv_sec * 1000000ULL + st->last_collected_time.tv_usec;
-       unsigned long long next_ut = (st->last_updated.tv_sec + st->update_every) * 1000000ULL;
+       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);
@@ -901,7 +945,7 @@ unsigned long long rrdset_done(RRDSET *st)
        // 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: "
+               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
@@ -914,26 +958,24 @@ unsigned long long rrdset_done(RRDSET *st)
                        );
 
                switch(rd->algorithm) {
-                       case RRDDIM_PCENT_OVER_DIFF_TOTAL:
-                               // 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;
+               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;
@@ -958,39 +1000,64 @@ unsigned long long rrdset_done(RRDSET *st)
                                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)) {
-                                       info("%s.%s: Detect RESET or OVERFLOW. Last collected value = " COLLECTED_NUMBER_FORMAT ", current = " COLLECTED_NUMBER_FORMAT
+                                       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);
-                                       storage_flags = SN_EXISTS_RESET;
+                                       if(!(rd->flags & RRDDIM_FLAG_DONT_DETECT_RESETS_OR_OVERFLOWS)) storage_flags = SN_EXISTS_RESET;
                                        rd->last_collected_value = rd->collected_value;
                                }
 
-                               rd->calculated_value += (calculated_number)(rd->collected_value - rd->last_collected_value);
+                               rd->calculated_value = (calculated_number)(rd->collected_value - rd->last_collected_value)
+                                       * (calculated_number)rd->multiplier
+                                       / (calculated_number)rd->divisor;
 
                                if(unlikely(st->debug))
-                                       debug(D_RRD_STATS, "%s/%s: CALC INC "
-                                               CALCULATED_NUMBER_FORMAT " += "
+                                       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_ABSOLUTE:
-                               rd->calculated_value = (calculated_number)rd->collected_value;
+                       case RRDDIM_PCENT_OVER_DIFF_TOTAL:
+                               if(unlikely(!rd->updated || rd->counter <= 1)) {
+                                       rd->calculated_value = 0;
+                                       continue;
+                               }
+
+                               // the percentage of the current increment
+                               // over the increment of all dimensions together
+                               if(unlikely(st->collected_total == st->last_collected_total)) rd->calculated_value = rd->last_calculated_value;
+                               else rd->calculated_value =
+                                         (calculated_number)100
+                                       * (calculated_number)(rd->collected_value - rd->last_collected_value)
+                                       / (calculated_number)(st->collected_total  - st->last_collected_total);
 
                                if(unlikely(st->debug))
-                                       debug(D_RRD_STATS, "%s/%s: CALC ABS/ABS-NO-IN "
-                                               CALCULATED_NUMBER_FORMAT " = "
-                                               COLLECTED_NUMBER_FORMAT
+                                       debug(D_RRD_STATS, "%s/%s: CALC PCENT-DIFF "
+                                               CALCULATED_NUMBER_FORMAT " = 100"
+                                               " * (" COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT ")"
+                                               " / (" COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT ")"
                                                , st->id, rd->name
                                                , rd->calculated_value
-                                               , rd->collected_value
+                                               , rd->collected_value, rd->last_collected_value
+                                               , st->collected_total, st->last_collected_total
                                                );
                                break;
 
@@ -1007,23 +1074,39 @@ unsigned long long rrdset_done(RRDSET *st)
                                                );
                                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;
-       int iterations = (now_ut - last_ut) / (st->update_every * 1000000ULL);
+       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(iterations < 0) error("iterations calculation wrapped!");
+#ifdef NETDATA_INTERNAL_CHECKS
+               if(iterations < 0) { error("%s: iterations calculation wrapped! first_ut = %llu, last_ut = %llu, next_ut = %llu, now_ut = %llu", st->name, first_ut, last_ut, next_ut, now_ut); }
+#endif
 
                if(unlikely(st->debug)) {
                        debug(D_RRD_STATS, "%s: last ut = %0.3Lf (last updated time)", st->name, (long double)last_ut/1000000.0);
                        debug(D_RRD_STATS, "%s: next ut = %0.3Lf (next interpolation point)", st->name, (long double)next_ut/1000000.0);
                }
 
-               st->last_updated.tv_sec = next_ut / 1000000ULL;
+               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 ) {
@@ -1046,39 +1129,57 @@ unsigned long long rrdset_done(RRDSET *st)
                                                        , st->id, rd->name
                                                        , new_value
                                                        , rd->calculated_value
-                                                       , (unsigned long long)(next_ut - last_ut)
-                                                       , (unsigned long long)(now_ut - last_ut)
+                                                       , (next_ut - last_ut)
+                                                       , (now_ut - last_ut)
                                                        );
 
                                        rd->calculated_value -= new_value;
+                                       new_value += rd->last_calculated_value;
+                                       rd->last_calculated_value = 0;
+                                       new_value /= (calculated_number)st->update_every;
                                        break;
 
                                case RRDDIM_ABSOLUTE:
                                case RRDDIM_PCENT_OVER_ROW_TOTAL:
                                case RRDDIM_PCENT_OVER_DIFF_TOTAL:
                                default:
-                                       new_value = (calculated_number)
-                                               (       (         (rd->calculated_value - rd->last_calculated_value)
-                                                               * (calculated_number)(next_ut - first_ut)
-                                                               / (calculated_number)(now_ut - first_ut)
-                                                       )
-                                                       +  rd->last_calculated_value
-                                               );
+                                       if(iterations == 1) {
+                                               // this is the last iteration
+                                               // do not interpolate
+                                               // just show the 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
+                                               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(likely(next_ut + st->update_every * 1000000ULL > now_ut)) rd->calculated_value = new_value;
+                                               if(unlikely(st->debug))
+                                                       debug(D_RRD_STATS, "%s/%s: CALC2 DEF "
+                                                               CALCULATED_NUMBER_FORMAT " = ((("
+                                                               "(" CALCULATED_NUMBER_FORMAT " - " CALCULATED_NUMBER_FORMAT ")"
+                                                               " * %llu"
+                                                               " / %llu) + " CALCULATED_NUMBER_FORMAT
+                                                               , st->id, rd->name
+                                                               , new_value
+                                                               , rd->calculated_value, rd->last_calculated_value
+                                                               , (next_ut - first_ut)
+                                                               , (now_ut - first_ut), rd->last_calculated_value
+                                                               );
+
+                                               // this is wrong
+                                               // it fades the value towards the target
+                                               // while we know the calculated value is different
+                                               // if(likely(next_ut + st->update_every * 1000000ULL > now_ut)) rd->calculated_value = new_value;
+                                       }
                                        break;
                        }
 
@@ -1087,23 +1188,15 @@ unsigned long long rrdset_done(RRDSET *st)
                                continue;
                        }
 
-                       if(likely(rd->updated && iterations < st->gap_when_lost_iterations_above)) {
-                               rd->values[st->current_entry] = pack_storage_number(
-                                                 new_value
-                                               * (calculated_number)rd->multiplier
-                                               / (calculated_number)rd->divisor
-                                       , storage_flags );
+                       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
-                                               " * %ld"
-                                               " / %ld"
                                                , st->id, rd->name
                                                , st->current_entry
                                                , unpack_storage_number(rd->values[st->current_entry]), new_value
-                                               , rd->multiplier
-                                               , rd->divisor
                                                );
                        }
                        else {
@@ -1114,6 +1207,8 @@ unsigned long long rrdset_done(RRDSET *st)
                                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]);
@@ -1150,23 +1245,38 @@ unsigned long long rrdset_done(RRDSET *st)
                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;
-               rd->last_collected_value = rd->collected_value;
-               rd->last_calculated_value = rd->calculated_value;
+
+               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 this is the first entry of incremental dimensions
-               // we have to set the first calculated_value to zero
-               // to eliminate the first spike
-               if(unlikely(st->counter_done == 1)) switch(rd->algorithm) {
-                       case RRDDIM_PCENT_OVER_DIFF_TOTAL:
-                       case RRDDIM_INCREMENTAL:
-                               rd->calculated_value = 0;
-                               // the next time, a new incremental total will be calculated
-                               break;
-               }
+               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;