Merging upstream version 1.37.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 909 insertions, 848 deletions

diff --git a/database/rrdset.c b/database/rrdset.c
index 9693ee211..6eb3c7105 100644
--- a/database/rrdset.c
+++ b/database/rrdset.c
@@ -3,97 +3,452 @@
 #define NETDATA_RRD_INTERNALS
 #include "rrd.h"
 #include <sched.h>
+#include "storage_engine.h"
 
-void __rrdset_check_rdlock(RRDSET *st, const char *file, const char *function, const unsigned long line) {
-    debug(D_RRD_CALLS, "Checking read lock on chart '%s'", st->id);
+// ----------------------------------------------------------------------------
+// RRDSET name index
 
-    int ret = netdata_rwlock_trywrlock(&st->rrdset_rwlock);
-    if(ret == 0)
-        fatal("RRDSET '%s' should be read-locked, but it is not, at function %s() at line %lu of file '%s'", st->id, function, line, file);
+static void rrdset_name_insert_callback(const DICTIONARY_ITEM *item __maybe_unused, void *rrdset, void *rrdhost __maybe_unused) {
+    RRDSET *st = rrdset;
+    rrdset_flag_set(st, RRDSET_FLAG_INDEXED_NAME);
+}
+static void rrdset_name_delete_callback(const DICTIONARY_ITEM *item __maybe_unused, void *rrdset, void *rrdhost __maybe_unused) {
+    RRDSET *st = rrdset;
+    rrdset_flag_clear(st, RRDSET_FLAG_INDEXED_NAME);
 }
 
-void __rrdset_check_wrlock(RRDSET *st, const char *file, const char *function, const unsigned long line) {
-    debug(D_RRD_CALLS, "Checking write lock on chart '%s'", st->id);
+static inline void rrdset_index_add_name(RRDHOST *host, RRDSET *st) {
+    if(!st->name) return;
+    dictionary_set(host->rrdset_root_index_name, rrdset_name(st), st, sizeof(RRDSET));
+}
 
-    int ret = netdata_rwlock_tryrdlock(&st->rrdset_rwlock);
-    if(ret == 0)
-        fatal("RRDSET '%s' should be write-locked, but it is not, at function %s() at line %lu of file '%s'", st->id, function, line, file);
+static inline void rrdset_index_del_name(RRDHOST *host, RRDSET *st) {
+    if(rrdset_flag_check(st, RRDSET_FLAG_INDEXED_NAME))
+        dictionary_del(host->rrdset_root_index_name, rrdset_name(st));
 }
 
+static inline RRDSET *rrdset_index_find_name(RRDHOST *host, const char *name) {
+    return dictionary_get(host->rrdset_root_index_name, name);
+}
 
 // ----------------------------------------------------------------------------
 // RRDSET index
 
-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);
+static inline void rrdset_update_permanent_labels(RRDSET *st) {
+    if(!st->rrdlabels) return;
+
+    rrdlabels_add(st->rrdlabels, "_collect_plugin", rrdset_plugin_name(st), RRDLABEL_SRC_AUTO| RRDLABEL_FLAG_PERMANENT);
+    rrdlabels_add(st->rrdlabels, "_collect_module", rrdset_module_name(st), RRDLABEL_SRC_AUTO| RRDLABEL_FLAG_PERMANENT);
 }
 
-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);
+static STRING *rrdset_fix_name(RRDHOST *host, const char *chart_full_id, const char *type, const char *current_name, const char *name) {
+    if(!name || !*name) return NULL;
+
+    char full_name[RRD_ID_LENGTH_MAX + 1];
+    char sanitized_name[CONFIG_MAX_VALUE + 1];
+    char new_name[CONFIG_MAX_VALUE + 1];
+
+    snprintfz(full_name, RRD_ID_LENGTH_MAX, "%s.%s", type, name);
+    rrdset_strncpyz_name(sanitized_name, full_name, CONFIG_MAX_VALUE);
+    strncpyz(new_name, sanitized_name, CONFIG_MAX_VALUE);
+
+    if(rrdset_index_find_name(host, new_name)) {
+        debug(D_RRD_CALLS, "RRDSET: chart name '%s' on host '%s' already exists.", new_name, rrdhost_hostname(host));
+        if(!strcmp(chart_full_id, full_name) && (!current_name || !*current_name)) {
+            unsigned i = 1;
+
+            do {
+                snprintfz(new_name, CONFIG_MAX_VALUE, "%s_%u", sanitized_name, i);
+                i++;
+            } while (rrdset_index_find_name(host, new_name));
 
-    return (RRDSET *)avl_search_lock(&(host->rrdset_root_index), (avl_t *) &tmp);
+            info("RRDSET: using name '%s' for chart '%s' on host '%s'.", new_name, full_name, rrdhost_hostname(host));
+        }
+        else
+            return NULL;
+    }
+
+    return string_strdupz(new_name);
 }
 
-// ----------------------------------------------------------------------------
-// RRDSET name index
+struct rrdset_constructor {
+    RRDHOST *host;
+    const char *type;
+    const char *id;
+    const char *name;
+    const char *family;
+    const char *context;
+    const char *title;
+    const char *units;
+    const char *plugin;
+    const char *module;
+    long priority;
+    int update_every;
+    RRDSET_TYPE chart_type;
+    RRD_MEMORY_MODE memory_mode;
+    long history_entries;
+
+    enum {
+        RRDSET_REACT_NONE                   = 0,
+        RRDSET_REACT_NEW                    = (1 << 0),
+        RRDSET_REACT_UPDATED                = (1 << 1),
+        RRDSET_REACT_PLUGIN_UPDATED         = (1 << 2),
+        RRDSET_REACT_MODULE_UPDATED         = (1 << 3),
+        RRDSET_REACT_CHART_ACTIVATED        = (1 << 4),
+    } react_action;
+};
+
+// the constructor - the dictionary is write locked while this runs
+static void rrdset_insert_callback(const DICTIONARY_ITEM *item __maybe_unused, void *rrdset, void *constructor_data) {
+    struct rrdset_constructor *ctr = constructor_data;
+    RRDHOST *host = ctr->host;
+    RRDSET *st = rrdset;
+
+    const char *chart_full_id = dictionary_acquired_item_name(item);
+
+    st->id = string_strdupz(chart_full_id);
+
+    st->name = rrdset_fix_name(host, chart_full_id, ctr->type, NULL, ctr->name);
+    if(!st->name)
+        st->name = rrdset_fix_name(host, chart_full_id, ctr->type, NULL, ctr->id);
+    rrdset_index_add_name(host, st);
+
+    st->parts.id = string_strdupz(ctr->id);
+    st->parts.type = string_strdupz(ctr->type);
+    st->parts.name = string_strdupz(ctr->name);
+
+    st->family = (ctr->family && *ctr->family) ? rrd_string_strdupz(ctr->family) : rrd_string_strdupz(ctr->type);
+    st->context = (ctr->context && *ctr->context) ? rrd_string_strdupz(ctr->context) : rrd_string_strdupz(chart_full_id);
+
+    st->units = rrd_string_strdupz(ctr->units);
+    st->title = rrd_string_strdupz(ctr->title);
+    st->plugin_name = rrd_string_strdupz(ctr->plugin);
+    st->module_name = rrd_string_strdupz(ctr->module);
+    st->priority = ctr->priority;
 
-#define rrdset_from_avlname(avlname_ptr) ((RRDSET *)((avlname_ptr) - offsetof(RRDSET, avlname)))
+    st->cache_dir = rrdset_cache_dir(host, chart_full_id);
+    st->entries = (ctr->memory_mode != RRD_MEMORY_MODE_DBENGINE) ? align_entries_to_pagesize(ctr->memory_mode, ctr->history_entries) : 5;
+    st->update_every = ctr->update_every;
+    st->rrd_memory_mode = ctr->memory_mode;
 
-int rrdset_compare_name(void* a, void* b) {
-    RRDSET *A = rrdset_from_avlname(a);
-    RRDSET *B = rrdset_from_avlname(b);
+    st->chart_type = ctr->chart_type;
+    st->gap_when_lost_iterations_above = (int) (gap_when_lost_iterations_above + 2);
+    st->rrdhost = host;
+
+    st->flags =   RRDSET_FLAG_SYNC_CLOCK
+                | RRDSET_FLAG_INDEXED_ID
+                | RRDSET_FLAG_RECEIVER_REPLICATION_FINISHED
+                | RRDSET_FLAG_SENDER_REPLICATION_FINISHED
+                ;
+
+    netdata_rwlock_init(&st->alerts.rwlock);
+
+    if(st->rrd_memory_mode == RRD_MEMORY_MODE_SAVE || st->rrd_memory_mode == RRD_MEMORY_MODE_MAP) {
+        if(!rrdset_memory_load_or_create_map_save(st, st->rrd_memory_mode)) {
+            info("Failed to use db mode %s for chart '%s', falling back to ram mode.", (st->rrd_memory_mode == RRD_MEMORY_MODE_MAP)?"map":"save", rrdset_name(st));
+            st->rrd_memory_mode = RRD_MEMORY_MODE_RAM;
+        }
+    }
+
+    // initialize the db tiers
+    {
+        for(size_t tier = 0; tier < storage_tiers ; tier++) {
+            STORAGE_ENGINE *eng = st->rrdhost->db[tier].eng;
+            if(!eng) continue;
+
+            st->storage_metrics_groups[tier] = eng->api.collect_ops.metrics_group_get(host->db[tier].instance, &st->chart_uuid);
+        }
+    }
+
+    rrddim_index_init(st);
+
+    // chart variables - we need this for data collection to work (collector given chart variables) - not only health
+    rrdsetvar_index_init(st);
+
+    if (host->health_enabled) {
+        st->rrdfamily = rrdfamily_add_and_acquire(host, rrdset_family(st));
+        st->rrdvars = rrdvariables_create();
+        rrddimvar_index_init(st);
+    }
+
+    st->rrdlabels = rrdlabels_create();
+    rrdset_update_permanent_labels(st);
 
-    // fprintf(stderr, "COMPARING: %s with %s\n", A->name, B->name);
+    st->green = NAN;
+    st->red = NAN;
 
-    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);
+    ctr->react_action = RRDSET_REACT_NEW;
 }
 
-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_t *) (&st->avlname));
-    if(result) return rrdset_from_avlname(result);
-    return NULL;
+// the destructor - the dictionary is write locked while this runs
+static void rrdset_delete_callback(const DICTIONARY_ITEM *item __maybe_unused, void *rrdset, void *rrdhost) {
+    RRDHOST *host = rrdhost;
+    RRDSET *st = rrdset;
+
+    rrdset_flag_clear(st, RRDSET_FLAG_INDEXED_ID);
+
+    // cleanup storage engines
+    {
+        for(size_t tier = 0; tier < storage_tiers ; tier++) {
+            STORAGE_ENGINE *eng = st->rrdhost->db[tier].eng;
+            if(!eng) continue;
+
+            eng->api.collect_ops.metrics_group_release(host->db[tier].instance, st->storage_metrics_groups[tier]);
+        }
+    }
+
+    // remove it from the name index
+    rrdset_index_del_name(host, st);
+
+    // release the collector info
+    dictionary_destroy(st->functions_view);
+
+    rrdcalc_unlink_all_rrdset_alerts(st);
+
+    // ------------------------------------------------------------------------
+    // the order of destruction is important here
+
+    // 1. delete RRDDIMVAR index - this will speed up the destruction of RRDDIMs
+    //    because each dimension loops to find its own variables in this index.
+    //    There are no references to the items on this index from the dimensions.
+    //    To find their own, they have to walk-through the dictionary.
+    rrddimvar_index_destroy(st);                // destroy the rrddimvar index
+
+    // 2. delete RRDSETVAR index
+    rrdsetvar_index_destroy(st);                // destroy the rrdsetvar index
+
+    // 3. delete RRDVAR index after the above, to avoid triggering its garbage collector (they have references on this)
+    rrdvariables_destroy(st->rrdvars);      // free all variables and destroy the rrdvar dictionary
+
+    // 4. delete RRDFAMILY - this has to be last, because RRDDIMVAR and RRDSETVAR need the reference counter
+    rrdfamily_release(host, st->rrdfamily); // release the acquired rrdfamily -- has to be after all variables
+
+    // 5. delete RRDDIMs, now their variables are not existing, so this is fast
+    rrddim_index_destroy(st);                   // free all the dimensions and destroy the dimensions index
+
+    // 6. this has to be after the dimensions are freed, but before labels are freed (contexts need the labels)
+    rrdcontext_removed_rrdset(st);              // let contexts know
+
+    // 7. destroy the chart labels
+    rrdlabels_destroy(st->rrdlabels);  // destroy the labels, after letting the contexts know
+
+    rrdset_memory_file_free(st);                // remove files of db mode save and map
+
+    // ------------------------------------------------------------------------
+    // free it
+
+    netdata_rwlock_destroy(&st->alerts.rwlock);
+
+    string_freez(st->id);
+    string_freez(st->name);
+    string_freez(st->parts.id);
+    string_freez(st->parts.type);
+    string_freez(st->parts.name);
+    string_freez(st->family);
+    string_freez(st->title);
+    string_freez(st->units);
+    string_freez(st->context);
+    string_freez(st->plugin_name);
+    string_freez(st->module_name);
+
+    freez(st->exporting_flags);
+    freez(st->cache_dir);
 }
 
-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_t *)(&st->avlname));
-    if(result) return rrdset_from_avlname(result);
-    return NULL;
+// the item to be inserted, is already in the dictionary
+// this callback deals with the situation, migrating the existing object to the new values
+// the dictionary is write locked while this runs
+static bool rrdset_conflict_callback(const DICTIONARY_ITEM *item __maybe_unused, void *rrdset, void *new_rrdset, void *constructor_data) {
+    (void)new_rrdset; // it is NULL
+
+    struct rrdset_constructor *ctr = constructor_data;
+    RRDSET *st = rrdset;
+
+    rrdset_isnot_obsolete(st);
+
+    ctr->react_action = RRDSET_REACT_NONE;
+
+    if (rrdset_flag_check(st, RRDSET_FLAG_ARCHIVED)) {
+        rrdset_flag_clear(st, RRDSET_FLAG_ARCHIVED);
+        ctr->react_action |= RRDSET_REACT_CHART_ACTIVATED;
+    }
+
+    if (rrdset_reset_name(st, (ctr->name && *ctr->name) ? ctr->name : ctr->id) == 2)
+        ctr->react_action |= RRDSET_REACT_UPDATED;
+
+    if (unlikely(st->priority != ctr->priority)) {
+        st->priority = ctr->priority;
+        ctr->react_action |= RRDSET_REACT_UPDATED;
+    }
+
+    if (unlikely(st->update_every != ctr->update_every)) {
+        rrdset_set_update_every(st, ctr->update_every);
+        ctr->react_action |= RRDSET_REACT_UPDATED;
+    }
+
+    if(ctr->plugin && *ctr->plugin) {
+        STRING *old_plugin = st->plugin_name;
+        st->plugin_name = rrd_string_strdupz(ctr->plugin);
+        if (old_plugin != st->plugin_name)
+            ctr->react_action |= RRDSET_REACT_PLUGIN_UPDATED;
+        string_freez(old_plugin);
+    }
+
+    if(ctr->module && *ctr->module) {
+        STRING *old_module = st->module_name;
+        st->module_name = rrd_string_strdupz(ctr->module);
+        if (old_module != st->module_name)
+            ctr->react_action |= RRDSET_REACT_MODULE_UPDATED;
+        string_freez(old_module);
+    }
+
+    if(ctr->title && *ctr->title) {
+        STRING *old_title = st->title;
+        st->title = rrd_string_strdupz(ctr->title);
+        if(old_title != st->title)
+            ctr->react_action |= RRDSET_REACT_UPDATED;
+        string_freez(old_title);
+    }
+
+    if(ctr->units && *ctr->units) {
+        STRING *old_units = st->units;
+        st->units = rrd_string_strdupz(ctr->units);
+        if(old_units != st->units)
+            ctr->react_action |= RRDSET_REACT_UPDATED;
+        string_freez(old_units);
+    }
+
+    if(ctr->family && *ctr->family) {
+        STRING *old_family = st->family;
+        st->family = rrd_string_strdupz(ctr->family);
+        if(old_family != st->family)
+            ctr->react_action |= RRDSET_REACT_UPDATED;
+        string_freez(old_family);
+
+        // TODO - we should rename RRDFAMILY variables
+    }
+
+    if(ctr->context && *ctr->context) {
+        STRING *old_context = st->context;
+        st->context = rrd_string_strdupz(ctr->context);
+        if(old_context != st->context)
+            ctr->react_action |= RRDSET_REACT_UPDATED;
+        string_freez(old_context);
+    }
+
+    if(st->chart_type != ctr->chart_type) {
+        st->chart_type = ctr->chart_type;
+        ctr->react_action |= RRDSET_REACT_UPDATED;
+    }
+
+    rrdset_update_permanent_labels(st);
+
+    rrdset_flag_set(st, RRDSET_FLAG_SYNC_CLOCK);
+    rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_EXPOSED);
+
+    return ctr->react_action != RRDSET_REACT_NONE;
 }
 
+// this is called after all insertions/conflicts, with the dictionary unlocked, with a reference to RRDSET
+// so, any actions requiring locks on other objects, should be placed here
+static void rrdset_react_callback(const DICTIONARY_ITEM *item __maybe_unused, void *rrdset, void *constructor_data) {
+    struct rrdset_constructor *ctr = constructor_data;
+    RRDSET *st = rrdset;
+    RRDHOST *host = st->rrdhost;
 
-// ----------------------------------------------------------------------------
-// RRDSET - find charts
+    st->last_accessed_time = now_realtime_sec();
+
+    if(host->health_enabled && (ctr->react_action & (RRDSET_REACT_NEW | RRDSET_REACT_CHART_ACTIVATED))) {
+        rrdset_flag_set(st, RRDSET_FLAG_PENDING_HEALTH_INITIALIZATION);
+        rrdhost_flag_set(st->rrdhost, RRDHOST_FLAG_PENDING_HEALTH_INITIALIZATION);
+    }
+
+    if(ctr->react_action & (RRDSET_REACT_NEW | RRDSET_REACT_PLUGIN_UPDATED | RRDSET_REACT_MODULE_UPDATED)) {
+        if (ctr->react_action & RRDSET_REACT_NEW) {
+            if(unlikely(rrdcontext_find_chart_uuid(st,  &st->chart_uuid))) {
+                uuid_generate(st->chart_uuid);
+                bool found_in_sql = false; (void)found_in_sql;
+
+//                bool found_in_sql = true;
+//                if(unlikely(sql_find_chart_uuid(host, st, &st->chart_uuid))) {
+//                    uuid_generate(st->chart_uuid);
+//                    found_in_sql = false;
+//                }
+
+#ifdef NETDATA_INTERNAL_CHECKS
+                char uuid_str[UUID_STR_LEN];
+                uuid_unparse_lower(st->chart_uuid, uuid_str);
+                error_report("Chart UUID for host %s chart [%s] not found in context. It is now set to %s (%s)",
+                             string2str(host->hostname),
+                             string2str(st->name), uuid_str, found_in_sql ? "found in sqlite" : "newly generated");
+#endif
+            }
+        }
+        rrdset_flag_set(st, RRDSET_FLAG_METADATA_UPDATE);
+        rrdhost_flag_set(st->rrdhost, RRDHOST_FLAG_METADATA_UPDATE);
+    }
+
+    rrdcontext_updated_rrdset(st);
+}
+
+void rrdset_index_init(RRDHOST *host) {
+    if(!host->rrdset_root_index) {
+        host->rrdset_root_index = dictionary_create(DICT_OPTION_DONT_OVERWRITE_VALUE);
+
+        dictionary_register_insert_callback(host->rrdset_root_index, rrdset_insert_callback, NULL);
+        dictionary_register_conflict_callback(host->rrdset_root_index, rrdset_conflict_callback, NULL);
+        dictionary_register_react_callback(host->rrdset_root_index, rrdset_react_callback, NULL);
+        dictionary_register_delete_callback(host->rrdset_root_index, rrdset_delete_callback, host);
+    }
+
+    if(!host->rrdset_root_index_name) {
+        host->rrdset_root_index_name = dictionary_create(
+            DICT_OPTION_NAME_LINK_DONT_CLONE | DICT_OPTION_VALUE_LINK_DONT_CLONE | DICT_OPTION_DONT_OVERWRITE_VALUE);
+
+        dictionary_register_insert_callback(host->rrdset_root_index_name, rrdset_name_insert_callback, host);
+        dictionary_register_delete_callback(host->rrdset_root_index_name, rrdset_name_delete_callback, host);
+    }
+}
 
-static inline 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);
+void rrdset_index_destroy(RRDHOST *host) {
+    // destroy the name index first
+    dictionary_destroy(host->rrdset_root_index_name);
+    host->rrdset_root_index_name = NULL;
 
-    result = avl_search_lock(&host->rrdset_root_index_name, (avl_t *) (&(tmp.avlname)));
-    if(result) return rrdset_from_avlname(result);
+    // destroy the id index last
+    dictionary_destroy(host->rrdset_root_index);
+    host->rrdset_root_index = NULL;
+}
+
+static inline RRDSET *rrdset_index_add(RRDHOST *host, const char *id, struct rrdset_constructor *st_ctr) {
+    return dictionary_set_advanced(host->rrdset_root_index, id, -1, NULL, sizeof(RRDSET), st_ctr);
+}
+
+static inline void rrdset_index_del(RRDHOST *host, RRDSET *st) {
+    if(rrdset_flag_check(st, RRDSET_FLAG_INDEXED_ID))
+        dictionary_del(host->rrdset_root_index, rrdset_id(st));
+}
 
-    return NULL;
+static RRDSET *rrdset_index_find(RRDHOST *host, const char *id) {
+    // TODO - the name index should have an acquired dictionary item, not just a pointer to RRDSET
+    return dictionary_get(host->rrdset_root_index, id);
 }
 
+// ----------------------------------------------------------------------------
+// RRDSET - find charts
+
 inline 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);
+    debug(D_RRD_CALLS, "rrdset_find() for chart '%s' in host '%s'", id, rrdhost_hostname(host));
+    RRDSET *st = rrdset_index_find(host, id);
+
+    if(st)
+        st->last_accessed_time = now_realtime_sec();
+
     return(st);
 }
 
 inline RRDSET *rrdset_find_bytype(RRDHOST *host, const char *type, const char *id) {
-    debug(D_RRD_CALLS, "rrdset_find_bytype() for chart '%s.%s' in host '%s'", type, id, host->hostname);
+    debug(D_RRD_CALLS, "rrdset_find_bytype() for chart '%s.%s' in host '%s'", type, id, rrdhost_hostname(host));
 
     char buf[RRD_ID_LENGTH_MAX + 1];
     strncpyz(buf, type, RRD_ID_LENGTH_MAX - 1);
@@ -105,8 +460,8 @@ inline RRDSET *rrdset_find_bytype(RRDHOST *host, const char *type, const char *i
 }
 
 inline 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);
+    debug(D_RRD_CALLS, "rrdset_find_byname() for chart '%s' in host '%s'", name, rrdhost_hostname(host));
+    RRDSET *st = rrdset_index_find_name(host, name);
     return(st);
 }
 
@@ -128,57 +483,32 @@ char *rrdset_strncpyz_name(char *to, const char *from, size_t length) {
     return to;
 }
 
-int rrdset_set_name(RRDSET *st, const char *name) {
-    if(unlikely(st->name && !strcmp(st->name, name)))
+int rrdset_reset_name(RRDSET *st, const char *name) {
+    if(unlikely(!strcmp(rrdset_name(st), name)))
         return 1;
 
     RRDHOST *host = st->rrdhost;
 
-    debug(D_RRD_CALLS, "rrdset_set_name() old: '%s', new: '%s'", st->name?st->name:"", name);
-
-    char full_name[RRD_ID_LENGTH_MAX + 1];
-    char sanitized_name[CONFIG_MAX_VALUE + 1];
-    char new_name[CONFIG_MAX_VALUE + 1];
-
-    snprintfz(full_name, RRD_ID_LENGTH_MAX, "%s.%s", st->type, name);
-    rrdset_strncpyz_name(sanitized_name, full_name, CONFIG_MAX_VALUE);
-    strncpyz(new_name, sanitized_name, CONFIG_MAX_VALUE);
-
-    if(rrdset_index_find_name(host, new_name, 0)) {
-        debug(D_RRD_CALLS, "RRDSET: chart name '%s' on host '%s' already exists.", new_name, host->hostname);
-        if(!strcmp(st->id, full_name) && !st->name) {
-            unsigned i = 1;
+    debug(D_RRD_CALLS, "rrdset_reset_name() old: '%s', new: '%s'", rrdset_name(st), name);
 
-            do {
-                snprintfz(new_name, CONFIG_MAX_VALUE, "%s_%u", sanitized_name, i);
-                i++;
-            } while (rrdset_index_find_name(host, new_name, 0));
-
-            info("RRDSET: using name '%s' for chart '%s' on host '%s'.", new_name, full_name, host->hostname);
-        } else {
-            return 0;
-        }
-    }
+    STRING *name_string = rrdset_fix_name(host, rrdset_id(st), rrdset_parts_type(st), string2str(st->name), name);
+    if(!name_string) return 0;
 
     if(st->name) {
         rrdset_index_del_name(host, st);
-        st->name = strdupz(new_name);
-        st->hash_name = simple_hash(st->name);
+        string_freez(st->name);
+        st->name = name_string;
         rrdsetvar_rename_all(st);
     }
-    else {
-        st->name = strdupz(new_name);
-        st->hash_name = simple_hash(st->name);
-    }
+    else
+        st->name = name_string;
 
-    rrdset_wrlock(st);
     RRDDIM *rd;
-    rrddim_foreach_write(rd, st)
+    rrddim_foreach_read(rd, st)
         rrddimvar_rename_all(rd);
-    rrdset_unlock(st);
+    rrddim_foreach_done(rd);
 
-    if(unlikely(rrdset_index_add_name(host, st) != st))
-        error("RRDSET: INTERNAL ERROR: attempted to index duplicate chart name '%s'", st->name);
+    rrdset_index_add_name(host, st);
 
     rrdset_flag_clear(st, RRDSET_FLAG_EXPORTING_SEND);
     rrdset_flag_clear(st, RRDSET_FLAG_EXPORTING_IGNORE);
@@ -190,15 +520,65 @@ int rrdset_set_name(RRDSET *st, const char *name) {
     return 2;
 }
 
+// get the timestamp of the last entry in the round-robin database
+time_t rrdset_last_entry_t(RRDSET *st) {
+    RRDDIM *rd;
+    time_t last_entry_t  = 0;
+
+    rrddim_foreach_read(rd, st) {
+        time_t t = rrddim_last_entry_t(rd);
+        if(t > last_entry_t) last_entry_t = t;
+    }
+    rrddim_foreach_done(rd);
+
+    return last_entry_t;
+}
+
+// get the timestamp of first entry in the round-robin database
+time_t rrdset_first_entry_t(RRDSET *st) {
+    RRDDIM *rd;
+    time_t first_entry_t = LONG_MAX;
+
+    rrddim_foreach_read(rd, st) {
+        time_t t = rrddim_first_entry_t(rd);
+        if(t < first_entry_t)
+            first_entry_t = t;
+    }
+    rrddim_foreach_done(rd);
+
+    if (unlikely(LONG_MAX == first_entry_t)) return 0;
+    return first_entry_t;
+}
+
+time_t rrdset_first_entry_t_of_tier(RRDSET *st, size_t tier) {
+    if(unlikely(tier > storage_tiers))
+        return 0;
+
+    RRDDIM *rd;
+    time_t first_entry_t = LONG_MAX;
+
+    rrddim_foreach_read(rd, st) {
+        time_t t = rrddim_first_entry_t_of_tier(rd, tier);
+        if(t && t < first_entry_t)
+            first_entry_t = t;
+    }
+    rrddim_foreach_done(rd);
+
+    if (unlikely(LONG_MAX == first_entry_t)) return 0;
+    return first_entry_t;
+}
+
 inline void rrdset_is_obsolete(RRDSET *st) {
     if(unlikely(rrdset_flag_check(st, RRDSET_FLAG_ARCHIVED))) {
-        info("Cannot obsolete already archived chart %s", st->name);
+        info("Cannot obsolete already archived chart %s", rrdset_name(st));
         return;
     }
 
     if(unlikely(!(rrdset_flag_check(st, RRDSET_FLAG_OBSOLETE)))) {
         rrdset_flag_set(st, RRDSET_FLAG_OBSOLETE);
-        st->rrdhost->obsolete_charts_count++;
+        rrdhost_flag_set(st->rrdhost, RRDHOST_FLAG_PENDING_OBSOLETE_CHARTS);
+
+        st->last_accessed_time = now_realtime_sec();
 
         rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_EXPOSED);
 
@@ -212,7 +592,7 @@ inline void rrdset_is_obsolete(RRDSET *st) {
 inline void rrdset_isnot_obsolete(RRDSET *st) {
     if(unlikely((rrdset_flag_check(st, RRDSET_FLAG_OBSOLETE)))) {
         rrdset_flag_clear(st, RRDSET_FLAG_OBSOLETE);
-        st->rrdhost->obsolete_charts_count--;
+        st->last_accessed_time = now_realtime_sec();
 
         rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_EXPOSED);
 
@@ -230,38 +610,52 @@ inline void rrdset_update_heterogeneous_flag(RRDSET *st) {
 
     rrdset_flag_clear(st, RRDSET_FLAG_HOMOGENEOUS_CHECK);
 
-    RRD_ALGORITHM algorithm = st->dimensions->algorithm;
-    collected_number multiplier = ABS(st->dimensions->multiplier);
-    collected_number divisor = ABS(st->dimensions->divisor);
+    bool init = false, is_heterogeneous = false;
+    RRD_ALGORITHM algorithm;
+    collected_number multiplier;
+    collected_number divisor;
 
     rrddim_foreach_read(rd, st) {
+        if(!init) {
+            algorithm = rd->algorithm;
+            multiplier = rd->multiplier;
+            divisor = ABS(rd->divisor);
+            init = true;
+            continue;
+        }
+
         if(algorithm != rd->algorithm || multiplier != ABS(rd->multiplier) || divisor != ABS(rd->divisor)) {
             if(!rrdset_flag_check(st, RRDSET_FLAG_HETEROGENEOUS)) {
                 #ifdef NETDATA_INTERNAL_CHECKS
                 info("Dimension '%s' added on chart '%s' of host '%s' is not homogeneous to other dimensions already present (algorithm is '%s' vs '%s', multiplier is " COLLECTED_NUMBER_FORMAT " vs " COLLECTED_NUMBER_FORMAT ", divisor is " COLLECTED_NUMBER_FORMAT " vs " COLLECTED_NUMBER_FORMAT ").",
-                        rd->name,
-                        st->name,
-                        host->hostname,
-                        rrd_algorithm_name(rd->algorithm), rrd_algorithm_name(algorithm),
-                        rd->multiplier, multiplier,
-                        rd->divisor, divisor
+                     rrddim_name(rd),
+                     rrdset_name(st),
+                     rrdhost_hostname(host),
+                     rrd_algorithm_name(rd->algorithm), rrd_algorithm_name(algorithm),
+                     rd->multiplier, multiplier,
+                     rd->divisor, divisor
                 );
                 #endif
                 rrdset_flag_set(st, RRDSET_FLAG_HETEROGENEOUS);
             }
-            return;
+
+            is_heterogeneous = true;
+            break;
         }
     }
+    rrddim_foreach_done(rd);
 
-    rrdset_flag_clear(st, RRDSET_FLAG_HETEROGENEOUS);
-    rrdcontext_updated_rrdset_flags(st);
+    if(!is_heterogeneous) {
+        rrdset_flag_clear(st, RRDSET_FLAG_HETEROGENEOUS);
+        rrdcontext_updated_rrdset_flags(st);
+    }
 }
 
 // ----------------------------------------------------------------------------
 // RRDSET - reset a chart
 
 void rrdset_reset(RRDSET *st) {
-    debug(D_RRD_CALLS, "rrdset_reset() %s", st->name);
+    debug(D_RRD_CALLS, "rrdset_reset() %s", rrdset_name(st));
 
     st->last_collected_time.tv_sec = 0;
     st->last_collected_time.tv_usec = 0;
@@ -270,7 +664,6 @@ void rrdset_reset(RRDSET *st) {
     st->current_entry = 0;
     st->counter = 0;
     st->counter_done = 0;
-    st->rrddim_page_alignment = 0;
 
     RRDDIM *rd;
     rrddim_foreach_read(rd, st) {
@@ -279,12 +672,13 @@ void rrdset_reset(RRDSET *st) {
         rd->collections_counter = 0;
 
         if(!rrddim_flag_check(rd, RRDDIM_FLAG_ARCHIVED)) {
-            for(int tier = 0; tier < storage_tiers ;tier++) {
+            for(size_t tier = 0; tier < storage_tiers ;tier++) {
                 if(rd->tiers[tier])
-                    rd->tiers[tier]->collect_ops.flush(rd->tiers[tier]->db_collection_handle);
+                    rd->tiers[tier]->collect_ops->flush(rd->tiers[tier]->db_collection_handle);
             }
         }
     }
+    rrddim_foreach_done(rd);
 }
 
 // ----------------------------------------------------------------------------
@@ -336,101 +730,22 @@ static inline void last_updated_time_align(RRDSET *st) {
 
 void rrdset_free(RRDSET *st) {
     if(unlikely(!st)) return;
-
-    RRDHOST *host = st->rrdhost;
-
-    rrdhost_check_wrlock(host);  // make sure we have a write lock on the host
-    rrdset_wrlock(st);                  // lock this RRDSET
-    // info("Removing chart '%s' ('%s')", st->id, st->name);
-
-    // ------------------------------------------------------------------------
-    // remove it from the indexes
-
-    if(unlikely(rrdset_index_del(host, st) != st))
-        error("RRDSET: INTERNAL ERROR: attempt to remove from index chart '%s', removed a different chart.", st->id);
-
-    rrdset_index_del_name(host, st);
-
-    // ------------------------------------------------------------------------
-    // free its children structures
-
-    freez(st->exporting_flags);
-
-    while(st->variables)  rrdsetvar_free(st->variables);
-//  while(st->alarms)     rrdsetcalc_unlink(st->alarms);
-    /* We must free all connected alarms here in case this has been an ephemeral chart whose alarm was
-     * created by a template. This leads to an effective memory leak, which cannot be detected since the
-     * alarms will still be connected to the host, and freed during shutdown. */
-    while(st->alarms)     rrdcalc_unlink_and_free(st->rrdhost, st->alarms);
-    while(st->dimensions) rrddim_free(st, st->dimensions);
-
-    rrdfamily_free(host, st->rrdfamily);
-
-    debug(D_RRD_CALLS, "RRDSET: Cleaning up remaining chart variables for host '%s', chart '%s'", host->hostname, st->id);
-    rrdvar_free_remaining_variables(host, &st->rrdvar_root_index);
-
-    // ------------------------------------------------------------------------
-    // unlink it from the host
-
-    if(st == host->rrdset_root) {
-        host->rrdset_root = st->next;
-    }
-    else {
-        // find the previous one
-        RRDSET *s;
-        for(s = host->rrdset_root; s && s->next != st ; s = s->next) ;
-
-        // bypass it
-        if(s) s->next = st->next;
-        else error("Request to free RRDSET '%s': cannot find it under host '%s'", st->id, host->hostname);
-    }
-
-    rrdset_unlock(st);
-
-    // this has to be after the dimensions are freed
-    rrdcontext_removed_rrdset(st);
-
-    // ------------------------------------------------------------------------
-    // free it
-
-    netdata_rwlock_destroy(&st->rrdset_rwlock);
-
-    // free directly allocated members
-    freez((void *)st->name);
-    freez(st->type);
-    freez(st->family);
-    freez(st->title);
-    freez(st->units);
-    freez(st->context);
-    freez(st->cache_dir);
-    freez(st->plugin_name);
-    freez(st->module_name);
-    freez(st->state->old_title);
-    freez(st->state->old_units);
-    freez(st->state->old_context);
-    rrdlabels_destroy(st->state->chart_labels);
-    freez(st->state);
-    freez(st->chart_uuid);
-
-    rrdset_memory_file_free(st);
-    freez(st);
+    rrdset_index_del(st->rrdhost, st);
 }
 
 void rrdset_save(RRDSET *st) {
-    rrdset_check_rdlock(st);
-
     rrdset_memory_file_save(st);
 
     RRDDIM *rd;
     rrddim_foreach_read(rd, st)
         rrddim_memory_file_save(rd);
+    rrddim_foreach_done(rd);
 }
 
 void rrdset_delete_files(RRDSET *st) {
     RRDDIM *rd;
-    rrdset_check_rdlock(st);
 
-    info("Deleting chart '%s' ('%s') from disk...", st->id, st->name);
+    info("Deleting chart '%s' ('%s') from disk...", rrdset_id(st), rrdset_name(st));
 
     if(st->rrd_memory_mode == RRD_MEMORY_MODE_SAVE || st->rrd_memory_mode == RRD_MEMORY_MODE_MAP) {
         const char *cache_filename = rrdset_cache_filename(st);
@@ -440,7 +755,7 @@ void rrdset_delete_files(RRDSET *st) {
                 error("Cannot delete chart header file '%s'", cache_filename);
         }
         else
-            error("Cannot find the cache filename of chart '%s'", st->id);
+            error("Cannot find the cache filename of chart '%s'", rrdset_id(st));
     }
 
     rrddim_foreach_read(rd, st) {
@@ -451,6 +766,7 @@ void rrdset_delete_files(RRDSET *st) {
         if(unlikely(unlink(cache_filename) == -1))
             error("Cannot delete dimension file '%s'", cache_filename);
     }
+    rrddim_foreach_done(rd);
 
     recursively_delete_dir(st->cache_dir, "left-over chart");
 }
@@ -458,9 +774,7 @@ void rrdset_delete_files(RRDSET *st) {
 void rrdset_delete_obsolete_dimensions(RRDSET *st) {
     RRDDIM *rd;
 
-    rrdset_check_rdlock(st);
-
-    info("Deleting dimensions of chart '%s' ('%s') from disk...", st->id, st->name);
+    info("Deleting dimensions of chart '%s' ('%s') from disk...", rrdset_id(st), rrdset_name(st));
 
     rrddim_foreach_read(rd, st) {
         if(rrddim_flag_check(rd, RRDDIM_FLAG_OBSOLETE)) {
@@ -471,30 +785,12 @@ void rrdset_delete_obsolete_dimensions(RRDSET *st) {
                 error("Cannot delete dimension file '%s'", cache_filename);
         }
     }
+    rrddim_foreach_done(rd);
 }
 
 // ----------------------------------------------------------------------------
 // RRDSET - create a chart
 
-static inline RRDSET *rrdset_find_on_create(RRDHOST *host, const char *fullid) {
-    RRDSET *st = rrdset_find(host, fullid);
-    if(unlikely(st)) {
-        rrdset_isnot_obsolete(st);
-        debug(D_RRD_CALLS, "RRDSET '%s', already exists.", fullid);
-        return st;
-    }
-
-    return NULL;
-}
-
-static inline void rrdset_update_permanent_labels(RRDSET *st) {
-    if(!st->state || !st->state->chart_labels) return;
-
-    rrdlabels_add(st->state->chart_labels, "_collect_plugin", st->plugin_name, RRDLABEL_SRC_AUTO| RRDLABEL_FLAG_PERMANENT);
-    rrdlabels_add(st->state->chart_labels, "_collect_module", st->module_name, RRDLABEL_SRC_AUTO| RRDLABEL_FLAG_PERMANENT);
-    rrdlabels_add(st->state->chart_labels, "_instance_family",   st->family,   RRDLABEL_SRC_AUTO| RRDLABEL_FLAG_PERMANENT);
-}
-
 RRDSET *rrdset_create_custom(
           RRDHOST *host
         , const char *type
@@ -512,7 +808,10 @@ RRDSET *rrdset_create_custom(
         , RRD_MEMORY_MODE memory_mode
         , long history_entries
 ) {
-    if(!type || !type[0]) {
+    if (host != localhost)
+        host->senders_last_chart_command = now_realtime_sec();
+
+    if(!type || !type[0])
         fatal("Cannot create rrd stats without a type: id '%s', name '%s', family '%s', context '%s', title '%s', units '%s', plugin '%s', module '%s'."
               , (id && *id)?id:"<unset>"
               , (name && *name)?name:"<unset>"
@@ -523,10 +822,8 @@ RRDSET *rrdset_create_custom(
               , (plugin && *plugin)?plugin:"<unset>"
               , (module && *module)?module:"<unset>"
         );
-        return NULL;
-    }
 
-    if(!id || !id[0]) {
+    if(!id || !id[0])
         fatal("Cannot create rrd stats without an id: type '%s', name '%s', family '%s', context '%s', title '%s', units '%s', plugin '%s', module '%s'."
               , type
               , (name && *name)?name:"<unset>"
@@ -537,311 +834,55 @@ RRDSET *rrdset_create_custom(
               , (plugin && *plugin)?plugin:"<unset>"
               , (module && *module)?module:"<unset>"
         );
-        return NULL;
-    }
-
-    if (host != localhost) {
-        host->senders_last_chart_command = now_realtime_sec();
-    }
 
     // ------------------------------------------------------------------------
     // check if it already exists
 
-    char fullid[RRD_ID_LENGTH_MAX + 1];
-    snprintfz(fullid, RRD_ID_LENGTH_MAX, "%s.%s", type, id);
-
-    int changed_from_archived_to_active = 0;
-    RRDSET *st = rrdset_find_on_create(host, fullid);
-    if (st) {
-        int mark_rebuild = 0;
-        if (rrdset_flag_check(st, RRDSET_FLAG_ARCHIVED)) {
-            rrdset_flag_clear(st, RRDSET_FLAG_ARCHIVED);
-            changed_from_archived_to_active = 1;
-            mark_rebuild |= META_CHART_ACTIVATED;
-        }
-        char *old_plugin = NULL, *old_module = NULL, *old_title = NULL, *old_context = NULL,
-             *old_title_v = NULL, *old_context_v = NULL, *old_units_v = NULL, *old_units = NULL;
-        int rc;
-
-        if(unlikely(name))
-            rc = rrdset_set_name(st, name);
-        else
-            rc = rrdset_set_name(st, id);
-
-        if (rc == 2)
-            mark_rebuild |= META_CHART_UPDATED;
-
-        if (unlikely(st->priority != priority)) {
-            st->priority = priority;
-            mark_rebuild |= META_CHART_UPDATED;
-        }
-        if (unlikely(st->rrd_memory_mode == RRD_MEMORY_MODE_DBENGINE && st->update_every != update_every)) {
-            st->update_every = update_every;
-            mark_rebuild |= META_CHART_UPDATED;
-        }
-
-        if (plugin && st->plugin_name) {
-            if (unlikely(strcmp(plugin, st->plugin_name))) {
-                old_plugin = st->plugin_name;
-                st->plugin_name = strdupz(plugin);
-                mark_rebuild |= META_PLUGIN_UPDATED;
-            }
-        } else {
-            if (plugin != st->plugin_name) { // one is NULL?
-                old_plugin = st->plugin_name;
-                st->plugin_name = plugin ? strdupz(plugin) : NULL;
-                mark_rebuild |= META_PLUGIN_UPDATED;
-            }
-        }
-
-        if (module && st->module_name) {
-            if (unlikely(strcmp(module, st->module_name))) {
-                old_module = st->module_name;
-                st->module_name = strdupz(module);
-                mark_rebuild |= META_MODULE_UPDATED;
-            }
-        } else {
-            if (module != st->module_name) {
-                if (st->module_name && *st->module_name) {
-                    old_module = st->module_name;
-                    st->module_name = module ? strdupz(module) : NULL;
-                    mark_rebuild |= META_MODULE_UPDATED;
-                }
-            }
-        }
-
-        if (unlikely(title && st->state->old_title && strcmp(st->state->old_title, title))) {
-            char *new_title = strdupz(title);
-            old_title_v = st->state->old_title;
-            st->state->old_title = strdupz(title);
-            json_fix_string(new_title);
-            old_title = st->title;
-            st->title = new_title;
-            mark_rebuild |= META_CHART_UPDATED;
-        }
-
-        if (unlikely(units && st->state->old_units && strcmp(st->state->old_units, units))) {
-            char *new_units = strdupz(units);
-            old_units_v = st->state->old_units;
-            st->state->old_units = strdupz(units);
-            json_fix_string(new_units);
-            old_units= st->units;
-            st->units = new_units;
-            mark_rebuild |= META_CHART_UPDATED;
-        }
-
-
-        if (st->chart_type != chart_type) {
-            st->chart_type = chart_type;
-            mark_rebuild |= META_CHART_UPDATED;
-        }
-
-        if (unlikely(context && st->state->old_context && strcmp(st->state->old_context, context))) {
-            char *new_context = strdupz(context);
-            old_context_v = st->state->old_context;
-            st->state->old_context = strdupz(context);
-            json_fix_string(new_context);
-            old_context = st->context;
-            st->context = new_context;
-            st->hash_context = simple_hash(st->context);
-            mark_rebuild |= META_CHART_UPDATED;
-        }
-
-        if (mark_rebuild) {
-            rrdset_flag_clear(st, RRDSET_FLAG_ACLK);
-            freez(old_plugin);
-            freez(old_module);
-            freez(old_title);
-            freez(old_units);
-            freez(old_context);
-            freez(old_title_v);
-            freez(old_units_v);
-            freez(old_context_v);
-            if (mark_rebuild != META_CHART_ACTIVATED) {
-                info("Collector updated metadata for chart %s", st->id);
-                sched_yield();
-            }
-        }
-        if (mark_rebuild & (META_CHART_UPDATED | META_PLUGIN_UPDATED | META_MODULE_UPDATED)) {
-            debug(D_METADATALOG, "CHART [%s] metadata updated", st->id);
-            int rc = update_chart_metadata(st->chart_uuid, st, id, name);
-            if (unlikely(rc))
-                error_report("Failed to update chart metadata in the database");
-
-            if (!changed_from_archived_to_active) {
-                rrdset_flag_set(st, RRDSET_FLAG_SYNC_CLOCK);
-                rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_EXPOSED);
-            }
-        }
-        /* Fall-through during switch from archived to active so that the host lock is taken and health is linked */
-        if (!changed_from_archived_to_active) {
-            rrdset_update_permanent_labels(st);
-            rrdcontext_updated_rrdset(st);
-            return st;
-        }
-    }
-
-    rrdhost_wrlock(host);
-
-    st = rrdset_find_on_create(host, fullid);
-    if(st) {
-        if (changed_from_archived_to_active) {
-            rrdset_flag_clear(st, RRDSET_FLAG_ARCHIVED);
-            rrdsetvar_create(st, "last_collected_t",    RRDVAR_TYPE_TIME_T,     &st->last_collected_time.tv_sec, RRDVAR_OPTION_DEFAULT);
-            rrdsetvar_create(st, "collected_total_raw", RRDVAR_TYPE_TOTAL,      &st->last_collected_total,       RRDVAR_OPTION_DEFAULT);
-            rrdsetvar_create(st, "green",               RRDVAR_TYPE_CALCULATED, &st->green,                      RRDVAR_OPTION_DEFAULT);
-            rrdsetvar_create(st, "red",                 RRDVAR_TYPE_CALCULATED, &st->red,                        RRDVAR_OPTION_DEFAULT);
-            rrdsetvar_create(st, "update_every",        RRDVAR_TYPE_INT,        &st->update_every,               RRDVAR_OPTION_DEFAULT);
-            rrdsetcalc_link_matching(st);
-            rrdcalctemplate_link_matching(st);
-        }
-        rrdhost_unlock(host);
-        rrdset_flag_set(st, RRDSET_FLAG_SYNC_CLOCK);
-        rrdset_flag_clear(st, RRDSET_FLAG_UPSTREAM_EXPOSED);
-        rrdcontext_updated_rrdset(st);
-        return st;
-    }
+    char full_id[RRD_ID_LENGTH_MAX + 1];
+    snprintfz(full_id, RRD_ID_LENGTH_MAX, "%s.%s", type, id);
 
     // ------------------------------------------------------------------------
-    // get the options from the config, we need to create it
-
-    long entries = 5;
-    if (memory_mode != RRD_MEMORY_MODE_DBENGINE)
-        entries = align_entries_to_pagesize(memory_mode, history_entries);
-
-    char *cache_dir = rrdset_cache_dir(host, fullid);
-
-    // ------------------------------------------------------------------------
-    // load it or allocate it
+    // allocate it
 
     debug(D_RRD_CALLS, "Creating RRD_STATS for '%s.%s'.", type, id);
 
-    st = callocz(1, sizeof(RRDSET));
-    st->state = callocz(1, sizeof(*st->state));
-
-    strcpy(st->id, fullid);
-    st->hash = simple_hash(st->id);
-
-    st->rrdhost = host;
-    st->cache_dir = cache_dir;
-    st->entries = entries;
-    st->update_every = update_every;
-
-    if(memory_mode == RRD_MEMORY_MODE_SAVE || memory_mode == RRD_MEMORY_MODE_MAP) {
-        if(!rrdset_memory_load_or_create_map_save(st, memory_mode)) {
-            info("Failed to use memory mode %s for chart '%s', falling back to ram", (memory_mode == RRD_MEMORY_MODE_MAP)?"map":"save", st->name);
-            memory_mode = RRD_MEMORY_MODE_RAM;
-        }
-    }
-    st->rrd_memory_mode = memory_mode;
-
-    st->plugin_name = plugin?strdupz(plugin):NULL;
-    st->module_name = module?strdupz(module):NULL;
-    st->chart_type  = chart_type;
-    st->type        = strdupz(type);
-    st->family      = family ? strdupz(family) : strdupz(st->type);
-    json_fix_string(st->family);
-
-    st->state->is_ar_chart = strcmp(st->id, ML_ANOMALY_RATES_CHART_ID) == 0;
-
-    st->units = units ? strdupz(units) : strdupz("");
-    st->state->old_units = strdupz(st->units);
-    json_fix_string(st->units);
-
-    st->context = context ? strdupz(context) : strdupz(st->id);
-    st->state->old_context = strdupz(st->context);
-    json_fix_string(st->context);
-    st->hash_context = simple_hash(st->context);
-
-    st->priority = priority;
-
-    rrdset_flag_set(st, RRDSET_FLAG_SYNC_CLOCK);
-
-    st->green = NAN;
-    st->red = NAN;
-
-    st->gap_when_lost_iterations_above = (int) (gap_when_lost_iterations_above + 2);
-
-    avl_init_lock(&st->dimensions_index, rrddim_compare);
-    avl_init_lock(&st->rrdvar_root_index, rrdvar_compare);
-
-    netdata_rwlock_init(&st->rrdset_rwlock);
-    st->state->chart_labels = rrdlabels_create();
-    rrdset_update_permanent_labels(st);
-
-    if(name && *name && rrdset_set_name(st, name))
-        // we did set the name
-        ;
-    else
-        // could not use the name, use the id
-        rrdset_set_name(st, id);
-
-    st->title = strdupz(title);
-    st->state->old_title = strdupz(st->title);
-    json_fix_string(st->title);
-
-    st->rrdfamily = rrdfamily_create(host, st->family);
-
-    st->next = host->rrdset_root;
-    host->rrdset_root = st;
-
-    if(host->health_enabled) {
-        rrdsetvar_create(st, "last_collected_t",    RRDVAR_TYPE_TIME_T,     &st->last_collected_time.tv_sec, RRDVAR_OPTION_DEFAULT);
-        rrdsetvar_create(st, "collected_total_raw", RRDVAR_TYPE_TOTAL,      &st->last_collected_total,       RRDVAR_OPTION_DEFAULT);
-        rrdsetvar_create(st, "green",               RRDVAR_TYPE_CALCULATED, &st->green,                      RRDVAR_OPTION_DEFAULT);
-        rrdsetvar_create(st, "red",                 RRDVAR_TYPE_CALCULATED, &st->red,                        RRDVAR_OPTION_DEFAULT);
-        rrdsetvar_create(st, "update_every",        RRDVAR_TYPE_INT,        &st->update_every,               RRDVAR_OPTION_DEFAULT);
-    }
-
-    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);
-
-    st->chart_uuid = find_chart_uuid(host, type, id, name);
-    if (unlikely(!st->chart_uuid))
-        st->chart_uuid = create_chart_uuid(st, id, name);
-    else
-        update_chart_metadata(st->chart_uuid, st, id, name);
-
-    store_active_chart(st->chart_uuid);
-    compute_chart_hash(st);
-
-    rrdhost_unlock(host);
-    rrdcontext_updated_rrdset(st);
+    struct rrdset_constructor tmp = {
+        .host = host,
+        .type = type,
+        .id = id,
+        .name = name,
+        .family = family,
+        .context = context,
+        .title = title,
+        .units = units,
+        .plugin = plugin,
+        .module = module,
+        .priority = priority,
+        .update_every = update_every,
+        .chart_type = chart_type,
+        .memory_mode = memory_mode,
+        .history_entries = history_entries,
+    };
+
+    RRDSET *st = rrdset_index_add(host, full_id, &tmp);
     return(st);
 }
 
-
 // ----------------------------------------------------------------------------
 // RRDSET - data collection iteration control
 
-inline void rrdset_next_usec_unfiltered(RRDSET *st, usec_t microseconds) {
-    if(unlikely(!st->last_collected_time.tv_sec || !microseconds || (rrdset_flag_check(st, RRDSET_FLAG_SYNC_CLOCK)))) {
-        // call the full next_usec() function
-        rrdset_next_usec(st, microseconds);
-        return;
-    }
-
-    st->usec_since_last_update = microseconds;
-}
-
-inline void rrdset_next_usec(RRDSET *st, usec_t microseconds) {
-    struct timeval now;
-    now_realtime_timeval(&now);
-
+void rrdset_timed_next(RRDSET *st, struct timeval now, usec_t duration_since_last_update) {
     #ifdef NETDATA_INTERNAL_CHECKS
     char *discard_reason = NULL;
-    usec_t discarded = microseconds;
+    usec_t discarded = duration_since_last_update;
     #endif
 
     if(unlikely(rrdset_flag_check(st, RRDSET_FLAG_SYNC_CLOCK))) {
         // the chart needs to be re-synced to current time
         rrdset_flag_clear(st, RRDSET_FLAG_SYNC_CLOCK);
 
-        // discard the microseconds supplied
-        microseconds = 0;
+        // discard the duration supplied
+        duration_since_last_update = 0;
 
         #ifdef NETDATA_INTERNAL_CHECKS
         if(!discard_reason) discard_reason = "SYNC CLOCK FLAG";
@@ -850,14 +891,14 @@ inline void rrdset_next_usec(RRDSET *st, usec_t microseconds) {
 
     if(unlikely(!st->last_collected_time.tv_sec)) {
         // the first entry
-        microseconds = st->update_every * USEC_PER_SEC;
+        duration_since_last_update = st->update_every * USEC_PER_SEC;
         #ifdef NETDATA_INTERNAL_CHECKS
         if(!discard_reason) discard_reason = "FIRST DATA COLLECTION";
         #endif
     }
-    else if(unlikely(!microseconds)) {
+    else if(unlikely(!duration_since_last_update)) {
         // no dt given by the plugin
-        microseconds = dt_usec(&now, &st->last_collected_time);
+        duration_since_last_update = dt_usec(&now, &st->last_collected_time);
         #ifdef NETDATA_INTERNAL_CHECKS
         if(!discard_reason) discard_reason = "NO USEC GIVEN BY COLLECTOR";
         #endif
@@ -870,7 +911,13 @@ inline void rrdset_next_usec(RRDSET *st, usec_t microseconds) {
             // oops! the database is in the future
             #ifdef NETDATA_INTERNAL_CHECKS
             info("RRD database for chart '%s' on host '%s' is %0.5" NETDATA_DOUBLE_MODIFIER
-                " secs in the future (counter #%zu, update #%zu). Adjusting it to current time.", st->id, st->rrdhost->hostname, (NETDATA_DOUBLE)-since_last_usec / USEC_PER_SEC, st->counter, st->counter_done);
+                " secs in the future (counter #%zu, update #%zu). Adjusting it to current time."
+                , rrdset_id(st)
+                , rrdhost_hostname(st->rrdhost)
+                , (NETDATA_DOUBLE)-since_last_usec / USEC_PER_SEC
+                , st->counter
+                , st->counter_done
+                );
             #endif
 
             st->last_collected_time.tv_sec  = now.tv_sec - st->update_every;
@@ -881,7 +928,7 @@ inline void rrdset_next_usec(RRDSET *st, usec_t microseconds) {
             st->last_updated.tv_usec = now.tv_usec;
             last_updated_time_align(st);
 
-            microseconds    = st->update_every * USEC_PER_SEC;
+            duration_since_last_update = st->update_every * USEC_PER_SEC;
             #ifdef NETDATA_INTERNAL_CHECKS
             if(!discard_reason) discard_reason = "COLLECTION TIME IN FUTURE";
             #endif
@@ -890,24 +937,24 @@ inline void rrdset_next_usec(RRDSET *st, usec_t microseconds) {
             // oops! the database is too far behind
             #ifdef NETDATA_INTERNAL_CHECKS
             info("RRD database for chart '%s' on host '%s' is %0.5" NETDATA_DOUBLE_MODIFIER
-                " secs in the past (counter #%zu, update #%zu). Adjusting it to current time.", st->id, st->rrdhost->hostname, (NETDATA_DOUBLE)since_last_usec / USEC_PER_SEC, st->counter, st->counter_done);
+                " secs in the past (counter #%zu, update #%zu). Adjusting it to current time.", rrdset_id(st), rrdhost_hostname(st->rrdhost), (NETDATA_DOUBLE)since_last_usec / USEC_PER_SEC, st->counter, st->counter_done);
             #endif
 
-            microseconds = (usec_t)since_last_usec;
+            duration_since_last_update = (usec_t)since_last_usec;
             #ifdef NETDATA_INTERNAL_CHECKS
             if(!discard_reason) discard_reason = "COLLECTION TIME TOO FAR IN THE PAST";
             #endif
         }
 
 #ifdef NETDATA_INTERNAL_CHECKS
-        if(since_last_usec > 0 && (susec_t)microseconds < since_last_usec) {
+        if(since_last_usec > 0 && (susec_t) duration_since_last_update < since_last_usec) {
             static __thread susec_t min_delta = USEC_PER_SEC * 3600, permanent_min_delta = 0;
             static __thread time_t last_t = 0;
 
             // the first time initialize it so that it will make the check later
             if(last_t == 0) last_t = now.tv_sec + 60;
 
-            susec_t delta = since_last_usec - (susec_t)microseconds;
+            susec_t delta = since_last_usec - (susec_t) duration_since_last_update;
             if(delta < min_delta) min_delta = delta;
 
             if(now.tv_sec >= last_t + 60) {
@@ -924,31 +971,49 @@ inline void rrdset_next_usec(RRDSET *st, usec_t microseconds) {
 #endif
     }
 
-    #ifdef NETDATA_INTERNAL_CHECKS
-    debug(D_RRD_CALLS, "rrdset_next_usec() for chart %s with microseconds %llu", st->name, microseconds);
-    rrdset_debug(st, "NEXT: %llu microseconds", microseconds);
+    debug(D_RRD_CALLS, "rrdset_timed_next() for chart %s with duration since last update %llu usec", rrdset_name(st), duration_since_last_update);
+    rrdset_debug(st, "NEXT: %llu microseconds", duration_since_last_update);
 
-    if(discarded && discarded != microseconds)
-        info("host '%s', chart '%s': discarded data collection time of %llu usec, replaced with %llu usec, reason: '%s'", st->rrdhost->hostname, st->id, discarded, microseconds, discard_reason?discard_reason:"UNDEFINED");
+    internal_error(discarded && discarded != duration_since_last_update,
+                   "host '%s', chart '%s': discarded data collection time of %llu usec, "
+                   "replaced with %llu usec, reason: '%s'"
+                   , rrdhost_hostname(st->rrdhost)
+                   , rrdset_id(st)
+                   , discarded
+                   , duration_since_last_update
+                   , discard_reason?discard_reason:"UNDEFINED"
+                   );
 
-    #endif
+    st->usec_since_last_update = duration_since_last_update;
+}
+
+inline void rrdset_next_usec_unfiltered(RRDSET *st, usec_t duration_since_last_update) {
+    if(unlikely(!st->last_collected_time.tv_sec || !duration_since_last_update || (rrdset_flag_check(st, RRDSET_FLAG_SYNC_CLOCK)))) {
+        // call the full next_usec() function
+        rrdset_next_usec(st, duration_since_last_update);
+        return;
+    }
 
-    st->usec_since_last_update = microseconds;
+    st->usec_since_last_update = duration_since_last_update;
 }
 
+inline void rrdset_next_usec(RRDSET *st, usec_t duration_since_last_update) {
+    struct timeval now;
+
+    now_realtime_timeval(&now);
+    rrdset_timed_next(st, now, duration_since_last_update);
+}
 
 // ----------------------------------------------------------------------------
 // RRDSET - process the collected values for all dimensions of a chart
 
-static inline usec_t rrdset_init_last_collected_time(RRDSET *st) {
-    now_realtime_timeval(&st->last_collected_time);
+static inline usec_t rrdset_init_last_collected_time(RRDSET *st, struct timeval now) {
+    st->last_collected_time = now;
     last_collected_time_align(st);
 
     usec_t last_collect_ut = st->last_collected_time.tv_sec * USEC_PER_SEC + st->last_collected_time.tv_usec;
 
-    #ifdef NETDATA_INTERNAL_CHECKS
     rrdset_debug(st, "initialized last collected time to %0.3" NETDATA_DOUBLE_MODIFIER, (NETDATA_DOUBLE)last_collect_ut / USEC_PER_SEC);
-    #endif
 
     return last_collect_ut;
 }
@@ -959,9 +1024,7 @@ static inline usec_t rrdset_update_last_collected_time(RRDSET *st) {
     st->last_collected_time.tv_sec = (time_t) (ut / USEC_PER_SEC);
     st->last_collected_time.tv_usec = (suseconds_t) (ut % USEC_PER_SEC);
 
-    #ifdef NETDATA_INTERNAL_CHECKS
     rrdset_debug(st, "updated last collected time to %0.3" NETDATA_DOUBLE_MODIFIER, (NETDATA_DOUBLE)last_collect_ut / USEC_PER_SEC);
-    #endif
 
     return last_collect_ut;
 }
@@ -978,22 +1041,51 @@ static inline usec_t rrdset_init_last_updated_time(RRDSET *st) {
 
     usec_t last_updated_ut = st->last_updated.tv_sec * USEC_PER_SEC + st->last_updated.tv_usec;
 
-    #ifdef NETDATA_INTERNAL_CHECKS
     rrdset_debug(st, "initialized last updated time to %0.3" NETDATA_DOUBLE_MODIFIER, (NETDATA_DOUBLE)last_updated_ut / USEC_PER_SEC);
-    #endif
 
     return last_updated_ut;
 }
 
+static __thread size_t rrdset_done_statistics_points_stored_per_tier[RRD_STORAGE_TIERS];
+
 static inline time_t tier_next_point_time(RRDDIM *rd, struct rrddim_tier *t, time_t now) {
     time_t loop = (time_t)rd->update_every * (time_t)t->tier_grouping;
     return now + loop - ((now + loop) % loop);
 }
 
-void store_metric_at_tier(RRDDIM *rd, struct rrddim_tier *t, STORAGE_POINT sp, usec_t now_ut) {
+void store_metric_at_tier(RRDDIM *rd, size_t tier, struct rrddim_tier *t, STORAGE_POINT sp, usec_t now_ut __maybe_unused) {
     if (unlikely(!t->next_point_time))
         t->next_point_time = tier_next_point_time(rd, t, sp.end_time);
 
+    if(unlikely(sp.start_time > t->next_point_time)) {
+        if (likely(!storage_point_is_unset(t->virtual_point))) {
+
+            t->collect_ops->store_metric(
+                t->db_collection_handle,
+                t->next_point_time * USEC_PER_SEC,
+                t->virtual_point.sum,
+                t->virtual_point.min,
+                t->virtual_point.max,
+                t->virtual_point.count,
+                t->virtual_point.anomaly_count,
+                t->virtual_point.flags);
+        }
+        else {
+            t->collect_ops->store_metric(
+                t->db_collection_handle,
+                t->next_point_time * USEC_PER_SEC,
+                NAN,
+                NAN,
+                NAN,
+                0,
+                0, SN_FLAG_NONE);
+        }
+
+        rrdset_done_statistics_points_stored_per_tier[tier]++;
+        t->virtual_point.count = 0; // make the point unset
+        t->next_point_time = tier_next_point_time(rd, t, sp.end_time);
+    }
+
     // merge the dates into our virtual point
     if (unlikely(sp.start_time < t->virtual_point.start_time))
         t->virtual_point.start_time = sp.start_time;
@@ -1019,72 +1111,105 @@ void store_metric_at_tier(RRDDIM *rd, struct rrddim_tier *t, STORAGE_POINT sp, u
             t->virtual_point = sp;
         }
     }
-
-    if(unlikely(sp.end_time >= t->next_point_time)) {
-        if (likely(!storage_point_is_unset(t->virtual_point))) {
-
-            t->collect_ops.store_metric(
-                t->db_collection_handle,
-                now_ut,
-                t->virtual_point.sum,
-                t->virtual_point.min,
-                t->virtual_point.max,
-                t->virtual_point.count,
-                t->virtual_point.anomaly_count,
-                t->virtual_point.flags);
-        }
-        else {
-            t->collect_ops.store_metric(
-                t->db_collection_handle,
-                now_ut,
-                NAN,
-                NAN,
-                NAN,
-                0,
-                0, SN_FLAG_NONE);
+}
+#ifdef NETDATA_LOG_COLLECTION_ERRORS
+void rrddim_store_metric_with_trace(RRDDIM *rd, usec_t point_end_time_ut, NETDATA_DOUBLE n, SN_FLAGS flags, const char *function) {
+#else // !NETDATA_LOG_COLLECTION_ERRORS
+void rrddim_store_metric(RRDDIM *rd, usec_t point_end_time_ut, NETDATA_DOUBLE n, SN_FLAGS flags) {
+#endif // !NETDATA_LOG_COLLECTION_ERRORS
+#ifdef NETDATA_LOG_COLLECTION_ERRORS
+    rd->rrddim_store_metric_count++;
+
+    if(likely(rd->rrddim_store_metric_count > 1)) {
+        usec_t expected = rd->rrddim_store_metric_last_ut + rd->update_every * USEC_PER_SEC;
+
+        if(point_end_time_ut != rd->rrddim_store_metric_last_ut) {
+            internal_error(true,
+                           "%s COLLECTION: 'host:%s/chart:%s/dim:%s' granularity %d, collection %zu, expected to store at tier 0 a value at %llu, but it gave %llu [%s%llu usec] (called from %s(), previously by %s())",
+                           (point_end_time_ut < rd->rrddim_store_metric_last_ut) ? "**PAST**" : "GAP",
+                           rrdhost_hostname(rd->rrdset->rrdhost), rrdset_id(rd->rrdset), rrddim_id(rd),
+                           rd->update_every,
+                           rd->rrddim_store_metric_count,
+                           expected, point_end_time_ut,
+                           (point_end_time_ut < rd->rrddim_store_metric_last_ut)?"by -" : "gap ",
+                           expected - point_end_time_ut,
+                           function,
+                           rd->rrddim_store_metric_last_caller?rd->rrddim_store_metric_last_caller:"none");
         }
-
-        t->virtual_point.count = 0;
-        t->next_point_time = tier_next_point_time(rd, t, sp.end_time);
     }
-}
 
-static void store_metric(RRDDIM *rd, usec_t point_end_time_ut, NETDATA_DOUBLE n, SN_FLAGS flags) {
+    rd->rrddim_store_metric_last_ut = point_end_time_ut;
+    rd->rrddim_store_metric_last_caller = function;
+#endif // NETDATA_LOG_COLLECTION_ERRORS
 
     // store the metric on tier 0
-    rd->tiers[0]->collect_ops.store_metric(rd->tiers[0]->db_collection_handle, point_end_time_ut, n, 0, 0, 1, 0, flags);
-
-    for(int tier = 1; tier < storage_tiers ;tier++) {
+    rd->tiers[0]->collect_ops->store_metric(rd->tiers[0]->db_collection_handle, point_end_time_ut, n, 0, 0, 1, 0, flags);
+    rrdset_done_statistics_points_stored_per_tier[0]++;
+
+    time_t now = (time_t)(point_end_time_ut / USEC_PER_SEC);
+
+    STORAGE_POINT sp = {
+        .start_time = now - rd->update_every,
+        .end_time = now,
+        .min = n,
+        .max = n,
+        .sum = n,
+        .count = 1,
+        .anomaly_count = (flags & SN_FLAG_NOT_ANOMALOUS) ? 0 : 1,
+        .flags = flags
+    };
+
+    for(size_t tier = 1; tier < storage_tiers ;tier++) {
         if(unlikely(!rd->tiers[tier])) continue;
 
         struct rrddim_tier *t = rd->tiers[tier];
 
-        time_t now = (time_t)(point_end_time_ut / USEC_PER_SEC);
-
-        if(!t->last_collected_ut) {
+        if(!rrddim_option_check(rd, RRDDIM_OPTION_BACKFILLED_HIGH_TIERS)) {
             // we have not collected this tier before
             // let's fill any gap that may exist
             rrdr_fill_tier_gap_from_smaller_tiers(rd, tier, now);
+            rrddim_option_set(rd, RRDDIM_OPTION_BACKFILLED_HIGH_TIERS);
         }
 
-        STORAGE_POINT sp = {
-            .start_time = now - rd->update_every,
-            .end_time = now,
-            .min = n,
-            .max = n,
-            .sum = n,
-            .count = 1,
-            .anomaly_count = (flags & SN_FLAG_NOT_ANOMALOUS) ? 0 : 1,
-            .flags = flags
-        };
+        store_metric_at_tier(rd, tier, t, sp, point_end_time_ut);
+    }
+}
+
+void store_metric_collection_completed() {
+    global_statistics_rrdset_done_chart_collection_completed(rrdset_done_statistics_points_stored_per_tier);
+}
+
+// caching of dimensions rrdset_done() and rrdset_done_interpolate() loop through
+struct rda_item {
+    const DICTIONARY_ITEM *item;
+    RRDDIM *rd;
+};
+
+static __thread struct rda_item *thread_rda = NULL;
+static __thread size_t thread_rda_entries = 0;
 
-        t->last_collected_ut = point_end_time_ut;
-        store_metric_at_tier(rd, t, sp, point_end_time_ut);
+struct rda_item *rrdset_thread_rda(size_t *dimensions) {
+
+    if(unlikely(!thread_rda || (*dimensions) > thread_rda_entries)) {
+        freez(thread_rda);
+        thread_rda = mallocz((*dimensions) * sizeof(struct rda_item));
+        thread_rda_entries = *dimensions;
     }
+
+    *dimensions = thread_rda_entries;
+    return thread_rda;
+}
+
+void rrdset_thread_rda_free(void) {
+    freez(thread_rda);
+    thread_rda = NULL;
+    thread_rda_entries = 0;
 }
 
 static inline size_t rrdset_done_interpolate(
         RRDSET *st
+        , struct rda_item *rda_base
+        , size_t rda_slots
         , usec_t update_every_ut
         , usec_t last_stored_ut
         , usec_t next_store_ut
@@ -1113,17 +1238,26 @@ static inline size_t rrdset_done_interpolate(
 
     for( ; next_store_ut <= now_collect_ut ; last_collect_ut = next_store_ut, next_store_ut += update_every_ut, iterations-- ) {
 
-        #ifdef NETDATA_INTERNAL_CHECKS
-        if(iterations < 0) { error("INTERNAL CHECK: %s: iterations calculation wrapped! first_ut = %llu, last_stored_ut = %llu, next_store_ut = %llu, now_collect_ut = %llu", st->name, first_ut, last_stored_ut, next_store_ut, now_collect_ut); }
+        internal_error(iterations < 0,
+                       "RRDSET: '%s': iterations calculation wrapped! "
+                       "first_ut = %llu, last_stored_ut = %llu, next_store_ut = %llu, now_collect_ut = %llu"
+                       , rrdset_id(st)
+                       , first_ut
+                       , last_stored_ut
+                       , next_store_ut
+                       , now_collect_ut
+                       );
+
         rrdset_debug(st, "last_stored_ut = %0.3" NETDATA_DOUBLE_MODIFIER " (last updated time)", (NETDATA_DOUBLE)last_stored_ut/USEC_PER_SEC);
         rrdset_debug(st, "next_store_ut  = %0.3" NETDATA_DOUBLE_MODIFIER " (next interpolation point)", (NETDATA_DOUBLE)next_store_ut/USEC_PER_SEC);
-        #endif
 
         last_ut = next_store_ut;
 
-        rrddim_foreach_read(rd, st) {
-            if (rrddim_flag_check(rd, RRDDIM_FLAG_ARCHIVED))
-                continue;
+        struct rda_item *rda;
+        size_t dim_id;
+        for(dim_id = 0, rda = rda_base ; dim_id < rda_slots ; ++dim_id, ++rda) {
+            rd = rda->rd;
+            if(unlikely(!rd)) continue;
 
             NETDATA_DOUBLE new_value;
 
@@ -1135,18 +1269,16 @@ static inline size_t rrdset_done_interpolate(
                                    / (NETDATA_DOUBLE)(now_collect_ut - last_collect_ut)
                             );
 
-                    #ifdef NETDATA_INTERNAL_CHECKS
                     rrdset_debug(st, "%s: CALC2 INC " NETDATA_DOUBLE_FORMAT " = "
                                  NETDATA_DOUBLE_FORMAT
                                 " * (%llu - %llu)"
                                 " / (%llu - %llu)"
-                              , rd->name
+                              , rrddim_name(rd)
                               , new_value
                               , rd->calculated_value
                               , next_store_ut, last_collect_ut
                               , now_collect_ut, last_collect_ut
                     );
-                    #endif
 
                     rd->calculated_value -= new_value;
                     new_value += rd->last_calculated_value;
@@ -1155,12 +1287,10 @@ static inline size_t rrdset_done_interpolate(
 
                     if(unlikely(next_store_ut - last_stored_ut < update_every_ut)) {
 
-                        #ifdef NETDATA_INTERNAL_CHECKS
                         rrdset_debug(st, "%s: COLLECTION POINT IS SHORT " NETDATA_DOUBLE_FORMAT " - EXTRAPOLATING",
-                                    rd->name
+                                    rrddim_name(rd)
                                   , (NETDATA_DOUBLE)(next_store_ut - last_stored_ut)
                         );
-                        #endif
 
                         new_value = new_value * (NETDATA_DOUBLE)(st->update_every * USEC_PER_SEC) / (NETDATA_DOUBLE)(next_store_ut - last_stored_ut);
                     }
@@ -1189,24 +1319,23 @@ static inline size_t rrdset_done_interpolate(
                                     +  rd->last_calculated_value
                                 );
 
-                        #ifdef NETDATA_INTERNAL_CHECKS
                         rrdset_debug(st, "%s: CALC2 DEF " NETDATA_DOUBLE_FORMAT " = ((("
                                             "(" NETDATA_DOUBLE_FORMAT " - " NETDATA_DOUBLE_FORMAT ")"
                                             " * %llu"
-                                            " / %llu) + " NETDATA_DOUBLE_FORMAT, rd->name
+                                            " / %llu) + " NETDATA_DOUBLE_FORMAT, rrddim_name(rd)
                                   , new_value
                                   , rd->calculated_value, rd->last_calculated_value
                                   , (next_store_ut - first_ut)
                                   , (now_collect_ut - first_ut), rd->last_calculated_value
                         );
-                        #endif
                     }
                     break;
             }
 
             if(unlikely(!store_this_entry)) {
                 (void) ml_is_anomalous(rd, 0, false);
-                store_metric(rd, next_store_ut, NAN, SN_FLAG_NONE);
+                rrddim_store_metric(rd, next_store_ut, NAN, SN_FLAG_NONE);
+                rrdcontext_collected_rrddim(rd);
                 continue;
             }
 
@@ -1218,17 +1347,17 @@ static inline size_t rrdset_done_interpolate(
                     dim_storage_flags &= ~((storage_number)SN_FLAG_NOT_ANOMALOUS);
                 }
 
-                store_metric(rd, next_store_ut, new_value, dim_storage_flags);
+                rrddim_store_metric(rd, next_store_ut, new_value, dim_storage_flags);
+                rrdcontext_collected_rrddim(rd);
                 rd->last_stored_value = new_value;
             }
             else {
                 (void) ml_is_anomalous(rd, 0, false);
 
-                #ifdef NETDATA_INTERNAL_CHECKS
-                rrdset_debug(st, "%s: STORE[%ld] = NON EXISTING ", rd->name, current_entry);
-                #endif
+                rrdset_debug(st, "%s: STORE[%ld] = NON EXISTING ", rrddim_name(rd), current_entry);
 
-                store_metric(rd, next_store_ut, NAN, SN_FLAG_NONE);
+                rrddim_store_metric(rd, next_store_ut, NAN, SN_FLAG_NONE);
+                rrdcontext_collected_rrddim(rd);
                 rd->last_stored_value = NAN;
             }
 
@@ -1274,11 +1403,10 @@ static inline void rrdset_done_fill_the_gap(RRDSET *st) {
             rd->db[current_entry] = pack_storage_number(NAN, SN_FLAG_NONE);
             current_entry = ((current_entry + 1) >= entries) ? 0 : current_entry + 1;
 
-            #ifdef NETDATA_INTERNAL_CHECKS
-            rrdset_debug(st, "%s: STORE[%ld] = NON EXISTING (FILLED THE GAP)", rd->name, current_entry);
-            #endif
+            rrdset_debug(st, "%s: STORE[%ld] = NON EXISTING (FILLED THE GAP)", rrddim_name(rd), current_entry);
         }
     }
+    rrddim_foreach_done(rd);
 
     if(c > 0) {
         c--;
@@ -1292,10 +1420,19 @@ static inline void rrdset_done_fill_the_gap(RRDSET *st) {
 }
 
 void rrdset_done(RRDSET *st) {
+    struct timeval now;
+
+    now_realtime_timeval(&now);
+    rrdset_timed_done(st, now, /* pending_rrdset_next = */ st->counter_done != 0);
+}
+
+void rrdset_timed_done(RRDSET *st, struct timeval now, bool pending_rrdset_next) {
     if(unlikely(netdata_exit)) return;
 
-    debug(D_RRD_CALLS, "rrdset_done() for chart %s", st->name);
-    rrdcontext_collected_rrdset(st);
+    if (pending_rrdset_next)
+        rrdset_next(st);
+
+    debug(D_RRD_CALLS, "rrdset_done() for chart '%s'", rrdset_name(st));
 
     RRDDIM *rd;
 
@@ -1312,44 +1449,29 @@ void rrdset_done(RRDSET *st) {
 
     netdata_thread_disable_cancelability();
 
-    // a read lock is OK here
-    rrdset_rdlock(st);
-
-#ifdef ENABLE_ACLK
-    if (likely(!st->state->is_ar_chart)) {
-        if (unlikely(!rrdset_flag_check(st, RRDSET_FLAG_ACLK))) {
-            if (likely(st->dimensions && st->counter_done && !queue_chart_to_aclk(st))) {
-                rrdset_flag_set(st, RRDSET_FLAG_ACLK);
-            }
-        }
-    }
-#endif
-
     if(unlikely(rrdset_flag_check(st, RRDSET_FLAG_OBSOLETE))) {
-        error("Chart '%s' has the OBSOLETE flag set, but it is collected.", st->id);
+        error("Chart '%s' has the OBSOLETE flag set, but it is collected.", rrdset_id(st));
         rrdset_isnot_obsolete(st);
     }
 
     // check if the chart has a long time to be updated
     if(unlikely(st->usec_since_last_update > st->entries * update_every_ut &&
                 st->rrd_memory_mode != RRD_MEMORY_MODE_DBENGINE && st->rrd_memory_mode != RRD_MEMORY_MODE_NONE)) {
-        info("host '%s', chart %s: took too long to be updated (counter #%zu, update #%zu, %0.3" NETDATA_DOUBLE_MODIFIER
-            " secs). Resetting it.", st->rrdhost->hostname, st->name, st->counter, st->counter_done, (NETDATA_DOUBLE)st->usec_since_last_update / USEC_PER_SEC);
+        info("host '%s', chart '%s': took too long to be updated (counter #%zu, update #%zu, %0.3" NETDATA_DOUBLE_MODIFIER
+            " secs). Resetting it.", rrdhost_hostname(st->rrdhost), rrdset_id(st), st->counter, st->counter_done, (NETDATA_DOUBLE)st->usec_since_last_update / USEC_PER_SEC);
         rrdset_reset(st);
         st->usec_since_last_update = update_every_ut;
         store_this_entry = 0;
         first_entry = 1;
     }
 
-    #ifdef NETDATA_INTERNAL_CHECKS
     rrdset_debug(st, "microseconds since last update: %llu", st->usec_since_last_update);
-    #endif
 
     // set last_collected_time
     if(unlikely(!st->last_collected_time.tv_sec)) {
         // it is the first entry
         // set the last_collected_time to now
-        last_collect_ut = rrdset_init_last_collected_time(st) - update_every_ut;
+        last_collect_ut = rrdset_init_last_collected_time(st, now) - update_every_ut;
 
         // the first entry should not be stored
         store_this_entry = 0;
@@ -1380,9 +1502,9 @@ void rrdset_done(RRDSET *st) {
     if(unlikely(dt_usec(&st->last_collected_time, &st->last_updated) > st->entries * update_every_ut &&
                 st->rrd_memory_mode != RRD_MEMORY_MODE_DBENGINE)) {
         info(
-            "%s: too old data (last updated at %"PRId64".%"PRId64", last collected at %"PRId64".%"PRId64"). "
+            "'%s': too old data (last updated at %"PRId64".%"PRId64", last collected at %"PRId64".%"PRId64"). "
             "Resetting it. Will not store the next entry.",
-            st->name,
+            rrdset_id(st),
             (int64_t)st->last_updated.tv_sec,
             (int64_t)st->last_updated.tv_usec,
             (int64_t)st->last_collected_time.tv_sec,
@@ -1402,9 +1524,9 @@ void rrdset_done(RRDSET *st) {
     if(unlikely(st->rrd_memory_mode == RRD_MEMORY_MODE_DBENGINE &&
                 dt_usec(&st->last_collected_time, &st->last_updated) > (RRDENG_BLOCK_SIZE / sizeof(storage_number)) * update_every_ut)) {
         info(
-            "%s: too old data (last updated at %" PRId64 ".%" PRId64 ", last collected at %" PRId64 ".%" PRId64 "). "
+            "'%s': too old data (last updated at %" PRId64 ".%" PRId64 ", last collected at %" PRId64 ".%" PRId64 "). "
             "Resetting it. Will not store the next entry.",
-            st->name,
+            rrdset_id(st),
             (int64_t)st->last_updated.tv_sec,
             (int64_t)st->last_updated.tv_usec,
             (int64_t)st->last_collected_time.tv_sec,
@@ -1449,79 +1571,108 @@ void rrdset_done(RRDSET *st) {
             store_this_entry = 1;
             last_collect_ut = next_store_ut - update_every_ut;
 
-            #ifdef NETDATA_INTERNAL_CHECKS
             rrdset_debug(st, "Fixed first entry.");
-            #endif
         }
         else {
             store_this_entry = 0;
 
-            #ifdef NETDATA_INTERNAL_CHECKS
             rrdset_debug(st, "Will not store the next entry.");
-            #endif
         }
     }
 
 after_first_database_work:
     st->counter_done++;
 
-    if(unlikely(st->rrdhost->rrdpush_send_enabled))
+    if(unlikely(rrdhost_has_rrdpush_sender_enabled(st->rrdhost)))
         rrdset_done_push(st);
-    if (unlikely(st->rrd_memory_mode == RRD_MEMORY_MODE_NONE)) {
-        goto after_second_database_work;
-    }
 
-    #ifdef NETDATA_INTERNAL_CHECKS
-    rrdset_debug(st, "last_collect_ut = %0.3" NETDATA_DOUBLE_MODIFIER " (last collection time)", (NETDATA_DOUBLE)last_collect_ut/USEC_PER_SEC);
-    rrdset_debug(st, "now_collect_ut  = %0.3" NETDATA_DOUBLE_MODIFIER " (current collection time)", (NETDATA_DOUBLE)now_collect_ut/USEC_PER_SEC);
-    rrdset_debug(st, "last_stored_ut  = %0.3" NETDATA_DOUBLE_MODIFIER " (last updated time)", (NETDATA_DOUBLE)last_stored_ut/USEC_PER_SEC);
-    rrdset_debug(st, "next_store_ut   = %0.3" NETDATA_DOUBLE_MODIFIER " (next interpolation point)", (NETDATA_DOUBLE)next_store_ut/USEC_PER_SEC);
-    #endif
+    uint32_t has_reset_value = 0;
 
-    // calculate totals and count the dimensions
-    int dimensions = 0;
-    st->collected_total = 0;
+    size_t rda_slots = dictionary_entries(st->rrddim_root_index);
+    struct rda_item *rda_base = rrdset_thread_rda(&rda_slots);
+
+    size_t dim_id;
+    size_t dimensions = 0;
+    struct rda_item *rda = rda_base;
+    total_number collected_total = 0;
+    total_number last_collected_total = 0;
     rrddim_foreach_read(rd, st) {
-        if (rrddim_flag_check(rd, RRDDIM_FLAG_ARCHIVED))
+        if(rd_dfe.counter >= rda_slots)
+            break;
+
+        rda = &rda_base[dimensions++];
+
+        if(rrddim_flag_check(rd, RRDDIM_FLAG_ARCHIVED)) {
+            rda->item = NULL;
+            rda->rd = NULL;
             continue;
+        }
+
+        // store the dimension in the array
+        rda->item = dictionary_acquired_item_dup(st->rrddim_root_index, rd_dfe.item);
+        rda->rd = dictionary_acquired_item_value(rda->item);
+
+        // calculate totals
+        if(likely(rd->updated)) {
+            // 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->algorithm == RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL && 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
+                , rrdset_id(st)
+                , rrddim_name(rd)
+                , rd->last_collected_value
+                , rd->collected_value
+                );
 
-        dimensions++;
+                if(!(rrddim_option_check(rd, RRDDIM_OPTION_DONT_DETECT_RESETS_OR_OVERFLOWS)))
+                    has_reset_value = 1;
 
-        if(likely(rd->updated))
-            st->collected_total += rd->collected_value;
+                rd->last_collected_value = rd->collected_value;
+            }
+
+            last_collected_total += rd->last_collected_value;
+            collected_total += rd->collected_value;
+
+            if(unlikely(rrddim_flag_check(rd, RRDDIM_FLAG_OBSOLETE))) {
+                error("Dimension %s in chart '%s' has the OBSOLETE flag set, but it is collected.", rrddim_name(rd), rrdset_id(st));
+                rrddim_isnot_obsolete(st, rd);
+            }
+        }
     }
+    rrddim_foreach_done(rd);
+    rda_slots = dimensions;
 
-    uint32_t has_reset_value = 0;
+    if (unlikely(st->rrd_memory_mode == RRD_MEMORY_MODE_NONE))
+        goto after_second_database_work;
+
+    rrdset_debug(st, "last_collect_ut = %0.3" NETDATA_DOUBLE_MODIFIER " (last collection time)", (NETDATA_DOUBLE)last_collect_ut/USEC_PER_SEC);
+    rrdset_debug(st, "now_collect_ut  = %0.3" NETDATA_DOUBLE_MODIFIER " (current collection time)", (NETDATA_DOUBLE)now_collect_ut/USEC_PER_SEC);
+    rrdset_debug(st, "last_stored_ut  = %0.3" NETDATA_DOUBLE_MODIFIER " (last updated time)", (NETDATA_DOUBLE)last_stored_ut/USEC_PER_SEC);
+    rrdset_debug(st, "next_store_ut   = %0.3" NETDATA_DOUBLE_MODIFIER " (next interpolation point)", (NETDATA_DOUBLE)next_store_ut/USEC_PER_SEC);
 
     // process all dimensions to calculate their values
     // based on the collected figures only
     // at this stage we do not interpolate anything
-    rrddim_foreach_read(rd, st) {
-        if (rrddim_flag_check(rd, RRDDIM_FLAG_ARCHIVED))
-            continue;
+    for(dim_id = 0, rda = rda_base ; dim_id < rda_slots ; ++dim_id, ++rda) {
+        rd = rda->rd;
+        if(unlikely(!rd)) continue;
 
         if(unlikely(!rd->updated)) {
             rd->calculated_value = 0;
             continue;
         }
 
-        if(unlikely(rrddim_flag_check(rd, RRDDIM_FLAG_OBSOLETE))) {
-            error("Dimension %s in chart '%s' has the OBSOLETE flag set, but it is collected.", rd->name, st->id);
-            rrddim_isnot_obsolete(st, rd);
-        }
-
-        #ifdef NETDATA_INTERNAL_CHECKS
         rrdset_debug(st, "%s: START "
                 " last_collected_value = " COLLECTED_NUMBER_FORMAT
                 " collected_value = " COLLECTED_NUMBER_FORMAT
                 " last_calculated_value = " NETDATA_DOUBLE_FORMAT
-                " calculated_value = " NETDATA_DOUBLE_FORMAT, rd->name
-                                      , rd->last_collected_value
-                                      , rd->collected_value
-                                      , rd->last_calculated_value
-                                      , rd->calculated_value
+                " calculated_value = " NETDATA_DOUBLE_FORMAT
+                     , rrddim_name(rd)
+                     , rd->last_collected_value
+                     , rd->collected_value
+                     , rd->last_calculated_value
+                     , rd->calculated_value
         );
-        #endif
 
         switch(rd->algorithm) {
             case RRD_ALGORITHM_ABSOLUTE:
@@ -1529,22 +1680,20 @@ after_first_database_work:
                                        * (NETDATA_DOUBLE)rd->multiplier
                                        / (NETDATA_DOUBLE)rd->divisor;
 
-                #ifdef NETDATA_INTERNAL_CHECKS
                 rrdset_debug(st, "%s: CALC ABS/ABS-NO-IN " NETDATA_DOUBLE_FORMAT " = "
                             COLLECTED_NUMBER_FORMAT
                             " * " NETDATA_DOUBLE_FORMAT
-                            " / " NETDATA_DOUBLE_FORMAT, rd->name
+                            " / " NETDATA_DOUBLE_FORMAT
+                          , rrddim_name(rd)
                           , rd->calculated_value
                           , rd->collected_value
                           , (NETDATA_DOUBLE)rd->multiplier
                           , (NETDATA_DOUBLE)rd->divisor
                 );
-                #endif
-
                 break;
 
             case RRD_ALGORITHM_PCENT_OVER_ROW_TOTAL:
-                if(unlikely(!st->collected_total))
+                if(unlikely(!collected_total))
                     rd->calculated_value = 0;
                 else
                     // the percentage of the current value
@@ -1552,19 +1701,16 @@ after_first_database_work:
                     rd->calculated_value =
                             (NETDATA_DOUBLE)100
                             * (NETDATA_DOUBLE)rd->collected_value
-                            / (NETDATA_DOUBLE)st->collected_total;
+                            / (NETDATA_DOUBLE)collected_total;
 
-                #ifdef NETDATA_INTERNAL_CHECKS
                 rrdset_debug(st, "%s: CALC PCENT-ROW " NETDATA_DOUBLE_FORMAT " = 100"
                             " * " COLLECTED_NUMBER_FORMAT
                             " / " COLLECTED_NUMBER_FORMAT
-                          , rd->name
+                          , rrddim_name(rd)
                           , rd->calculated_value
                           , rd->collected_value
-                          , st->collected_total
+                          , collected_total
                 );
-                #endif
-
                 break;
 
             case RRD_ALGORITHM_INCREMENTAL:
@@ -1578,12 +1724,13 @@ after_first_database_work:
                 // It is imperative to set the comparison to uint64_t since type collected_number is signed and
                 // produces wrong results as far as incremental counters are concerned.
                 if(unlikely((uint64_t)rd->last_collected_value > (uint64_t)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
+                    debug(D_RRD_STATS, "'%s' / '%s': RESET or OVERFLOW. Last collected value = " COLLECTED_NUMBER_FORMAT ", current = " COLLECTED_NUMBER_FORMAT
+                          , rrdset_id(st)
+                          , rrddim_name(rd)
                           , rd->last_collected_value
                           , rd->collected_value);
 
-                    if(!(rrddim_flag_check(rd, RRDDIM_FLAG_DONT_DETECT_RESETS_OR_OVERFLOWS)))
+                    if(!(rrddim_option_check(rd, RRDDIM_OPTION_DONT_DETECT_RESETS_OR_OVERFLOWS)))
                         has_reset_value = 1;
 
                     uint64_t last = (uint64_t)rd->last_collected_value;
@@ -1622,19 +1769,17 @@ after_first_database_work:
                             / (NETDATA_DOUBLE) rd->divisor;
                 }
 
-                #ifdef NETDATA_INTERNAL_CHECKS
                 rrdset_debug(st, "%s: CALC INC PRE " NETDATA_DOUBLE_FORMAT " = ("
                             COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT
                             ")"
                                     " * " NETDATA_DOUBLE_FORMAT
-                            " / " NETDATA_DOUBLE_FORMAT, rd->name
+                            " / " NETDATA_DOUBLE_FORMAT
+                          , rrddim_name(rd)
                           , rd->calculated_value
                           , rd->collected_value, rd->last_collected_value
                           , (NETDATA_DOUBLE)rd->multiplier
                           , (NETDATA_DOUBLE)rd->divisor
                 );
-                #endif
-
                 break;
 
             case RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL:
@@ -1643,42 +1788,24 @@ after_first_database_work:
                     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(!(rrddim_flag_check(rd, RRDDIM_FLAG_DONT_DETECT_RESETS_OR_OVERFLOWS)))
-                        has_reset_value = 1;
-
-                    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))
+                if(unlikely(collected_total == last_collected_total))
                     rd->calculated_value = 0;
                 else
                     rd->calculated_value =
                             (NETDATA_DOUBLE)100
                             * (NETDATA_DOUBLE)(rd->collected_value - rd->last_collected_value)
-                            / (NETDATA_DOUBLE)(st->collected_total - st->last_collected_total);
+                            / (NETDATA_DOUBLE)(collected_total - last_collected_total);
 
-                #ifdef NETDATA_INTERNAL_CHECKS
                 rrdset_debug(st, "%s: CALC PCENT-DIFF " NETDATA_DOUBLE_FORMAT " = 100"
                             " * (" COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT ")"
                             " / (" COLLECTED_NUMBER_FORMAT " - " COLLECTED_NUMBER_FORMAT ")"
-                          , rd->name
+                          , rrddim_name(rd)
                           , rd->calculated_value
                           , rd->collected_value, rd->last_collected_value
-                          , st->collected_total, st->last_collected_total
+                          , collected_total, last_collected_total
                 );
-                #endif
-
                 break;
 
             default:
@@ -1686,43 +1813,41 @@ after_first_database_work:
                 // it gets noticed when we add new types
                 rd->calculated_value = 0;
 
-                #ifdef NETDATA_INTERNAL_CHECKS
                 rrdset_debug(st, "%s: CALC " NETDATA_DOUBLE_FORMAT " = 0"
-                          , rd->name
+                          , rrddim_name(rd)
                           , rd->calculated_value
                 );
-                #endif
-
                 break;
         }
 
-        #ifdef NETDATA_INTERNAL_CHECKS
         rrdset_debug(st, "%s: PHASE2 "
                     " last_collected_value = " COLLECTED_NUMBER_FORMAT
                     " collected_value = " COLLECTED_NUMBER_FORMAT
                     " last_calculated_value = " NETDATA_DOUBLE_FORMAT
-                    " calculated_value = " NETDATA_DOUBLE_FORMAT, rd->name
-                                      , rd->last_collected_value
-                                      , rd->collected_value
-                                      , rd->last_calculated_value
-                                      , rd->calculated_value
+                    " calculated_value = " NETDATA_DOUBLE_FORMAT
+                    , rrddim_name(rd)
+                    , rd->last_collected_value
+                    , rd->collected_value
+                    , rd->last_calculated_value
+                    , rd->calculated_value
         );
-        #endif
-
     }
 
     // at this point we have all the calculated values ready
     // it is now time to interpolate values on a second boundary
 
-#ifdef NETDATA_INTERNAL_CHECKS
-    if(unlikely(now_collect_ut < next_store_ut && st->counter_done > 1)) {
-        // this is collected in the same interpolation point
-        rrdset_debug(st, "THIS IS IN THE SAME INTERPOLATION POINT");
-        info("INTERNAL CHECK: host '%s', chart '%s' collection %zu is in the same interpolation point: short by %llu microseconds", st->rrdhost->hostname, st->name, st->counter_done, next_store_ut - now_collect_ut);
-    }
-#endif
-
-    rrdset_done_interpolate(st
+// #ifdef NETDATA_INTERNAL_CHECKS
+//     if(unlikely(now_collect_ut < next_store_ut && st->counter_done > 1)) {
+//         // this is collected in the same interpolation point
+//         rrdset_debug(st, "THIS IS IN THE SAME INTERPOLATION POINT");
+//         info("INTERNAL CHECK: host '%s', chart '%s' collection %zu is in the same interpolation point: short by %llu microseconds", st->rrdhost->hostname, rrdset_name(st), st->counter_done, next_store_ut - now_collect_ut);
+//     }
+// #endif
+
+    rrdset_done_interpolate(
+            st
+            , rda_base
+            , rda_slots
             , update_every_ut
             , last_stored_ut
             , next_store_ut
@@ -1733,54 +1858,41 @@ after_first_database_work:
     );
 
 after_second_database_work:
-    st->last_collected_total  = st->collected_total;
+    for(dim_id = 0, rda = rda_base ; dim_id < rda_slots ; ++dim_id, ++rda) {
+        rd = rda->rd;
+        if(unlikely(!rd)) continue;
 
-#ifdef ENABLE_ACLK
-    time_t mark = now_realtime_sec();
-#endif
-    rrddim_foreach_read(rd, st) {
-        if (rrddim_flag_check(rd, RRDDIM_FLAG_ARCHIVED))
-            continue;
-
-#ifdef ENABLE_ACLK
-        if (likely(!st->state->is_ar_chart)) {
-            if (!rrddim_flag_check(rd, RRDDIM_FLAG_HIDDEN) && likely(rrdset_flag_check(st, RRDSET_FLAG_ACLK)))
-                queue_dimension_to_aclk(rd, calc_dimension_liveness(rd, mark));
-        }
-#endif
         if(unlikely(!rd->updated))
             continue;
 
-        #ifdef NETDATA_INTERNAL_CHECKS
-        rrdset_debug(st, "%s: setting last_collected_value (old: " COLLECTED_NUMBER_FORMAT ") to last_collected_value (new: " COLLECTED_NUMBER_FORMAT ")", rd->name, rd->last_collected_value, rd->collected_value);
-        #endif
+        rrdset_debug(st, "%s: setting last_collected_value (old: " COLLECTED_NUMBER_FORMAT ") to last_collected_value (new: " COLLECTED_NUMBER_FORMAT ")", rrddim_name(rd), rd->last_collected_value, rd->collected_value);
 
         rd->last_collected_value = rd->collected_value;
 
         switch(rd->algorithm) {
             case RRD_ALGORITHM_INCREMENTAL:
                 if(unlikely(!first_entry)) {
-                    #ifdef NETDATA_INTERNAL_CHECKS
-                    rrdset_debug(st, "%s: setting last_calculated_value (old: " NETDATA_DOUBLE_FORMAT
-                        ") to last_calculated_value (new: " NETDATA_DOUBLE_FORMAT ")", rd->name, rd->last_calculated_value + rd->calculated_value, rd->calculated_value);
-                    #endif
+                    rrdset_debug(st, "%s: setting last_calculated_value (old: " NETDATA_DOUBLE_FORMAT ") to "
+                                     "last_calculated_value (new: " NETDATA_DOUBLE_FORMAT ")"
+                        , rrddim_name(rd)
+                        , rd->last_calculated_value + rd->calculated_value
+                        , rd->calculated_value);
 
                     rd->last_calculated_value += rd->calculated_value;
                 }
                 else {
-                    #ifdef NETDATA_INTERNAL_CHECKS
                     rrdset_debug(st, "THIS IS THE FIRST POINT");
-                    #endif
                 }
                 break;
 
             case RRD_ALGORITHM_ABSOLUTE:
             case RRD_ALGORITHM_PCENT_OVER_ROW_TOTAL:
             case RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL:
-                #ifdef NETDATA_INTERNAL_CHECKS
-                rrdset_debug(st, "%s: setting last_calculated_value (old: " NETDATA_DOUBLE_FORMAT
-                    ") to last_calculated_value (new: " NETDATA_DOUBLE_FORMAT ")", rd->name, rd->last_calculated_value, rd->calculated_value);
-                #endif
+                rrdset_debug(st, "%s: setting last_calculated_value (old: " NETDATA_DOUBLE_FORMAT ") to "
+                                 "last_calculated_value (new: " NETDATA_DOUBLE_FORMAT ")"
+                    , rrddim_name(rd)
+                    , rd->last_calculated_value
+                    , rd->calculated_value);
 
                 rd->last_calculated_value = rd->calculated_value;
                 break;
@@ -1790,19 +1902,17 @@ after_second_database_work:
         rd->collected_value = 0;
         rd->updated = 0;
 
-        #ifdef NETDATA_INTERNAL_CHECKS
         rrdset_debug(st, "%s: END "
                     " last_collected_value = " COLLECTED_NUMBER_FORMAT
                     " collected_value = " COLLECTED_NUMBER_FORMAT
                     " last_calculated_value = " NETDATA_DOUBLE_FORMAT
-                    " calculated_value = " NETDATA_DOUBLE_FORMAT, rd->name
-                                      , rd->last_collected_value
-                                      , rd->collected_value
-                                      , rd->last_calculated_value
-                                      , rd->calculated_value
+                    " calculated_value = " NETDATA_DOUBLE_FORMAT
+                    , rrddim_name(rd)
+                    , rd->last_collected_value
+                    , rd->collected_value
+                    , rd->last_calculated_value
+                    , rd->calculated_value
         );
-        #endif
-
     }
 
     // ALL DONE ABOUT THE DATA UPDATE
@@ -1812,99 +1922,54 @@ after_second_database_work:
         // update the memory mapped files with the latest values
 
         rrdset_memory_file_update(st);
-        rrddim_foreach_read(rd, st) {
+
+        for(dim_id = 0, rda = rda_base; dim_id < rda_slots ; ++dim_id, ++rda) {
+            rd = rda->rd;
+            if(unlikely(!rd)) continue;
             rrddim_memory_file_update(rd);
         }
     }
 
-    // find if there are any obsolete dimensions
-    if(unlikely(rrdset_flag_check(st, RRDSET_FLAG_OBSOLETE_DIMENSIONS))) {
-        rrddim_foreach_read(rd, st)
-            if(unlikely(rrddim_flag_check(rd, RRDDIM_FLAG_OBSOLETE)))
-                break;
+    for(dim_id = 0, rda = rda_base; dim_id < rda_slots ; ++dim_id, ++rda) {
+        rd = rda->rd;
+        if(unlikely(!rd)) continue;
 
-        if(unlikely(rd)) {
-            time_t now = now_realtime_sec();
-
-            RRDDIM *last;
-            // there is a dimension to free
-            // upgrade our read lock to a write lock
-            rrdset_unlock(st);
-            rrdset_wrlock(st);
-
-            for( rd = st->dimensions, last = NULL ; likely(rd) ; ) {
-                if(unlikely(rrddim_flag_check(rd, RRDDIM_FLAG_OBSOLETE) &&  !rrddim_flag_check(rd, RRDDIM_FLAG_ACLK)
-                             && (rd->last_collected_time.tv_sec + rrdset_free_obsolete_time < now))) {
-                    info("Removing obsolete dimension '%s' (%s) of '%s' (%s).", rd->name, rd->id, st->name, st->id);
-
-                    const char *cache_filename = rrddim_cache_filename(rd);
-                    if(cache_filename) {
-                        info("Deleting dimension file '%s'.", cache_filename);
-                        if (unlikely(unlink(cache_filename) == -1))
-                            error("Cannot delete dimension file '%s'", cache_filename);
-                    }
-
-#ifdef ENABLE_DBENGINE
-                    if (rd->rrd_memory_mode == RRD_MEMORY_MODE_DBENGINE) {
-                        rrddim_flag_set(rd, RRDDIM_FLAG_ARCHIVED);
-                        while(rd->variables)
-                            rrddimvar_free(rd->variables);
-
-                        rrddim_flag_clear(rd, RRDDIM_FLAG_OBSOLETE);
-                        /* only a collector can mark a chart as obsolete, so we must remove the reference */
-
-                        size_t tiers_available = 0, tiers_said_yes = 0;
-                        for(int tier = 0; tier < storage_tiers ;tier++) {
-                            if(rd->tiers[tier]) {
-                                tiers_available++;
-
-                                if(rd->tiers[tier]->collect_ops.finalize(rd->tiers[tier]->db_collection_handle))
-                                    tiers_said_yes++;
-
-                                rd->tiers[tier]->db_collection_handle = NULL;
-                            }
-                        }
-
-                        if (tiers_available == tiers_said_yes && tiers_said_yes) {
-                            /* This metric has no data and no references */
-                            delete_dimension_uuid(&rd->metric_uuid);
-                        } else {
-                            /* Do not delete this dimension */
-#ifdef ENABLE_ACLK
-                            queue_dimension_to_aclk(rd, calc_dimension_liveness(rd, mark));
-#endif
-                            last = rd;
-                            rd = rd->next;
-                            continue;
-                        }
-                    }
-#endif
-                    if(unlikely(!last)) {
-                        rrddim_free(st, rd);
-                        rd = st->dimensions;
-                        continue;
-                    }
-                    else {
-                        rrddim_free(st, rd);
-                        rd = last->next;
-                        continue;
-                    }
-                }
-
-                last = rd;
-                rd = rd->next;
-            }
-        }
-        else {
-            rrdset_flag_clear(st, RRDSET_FLAG_OBSOLETE_DIMENSIONS);
-        }
+        dictionary_acquired_item_release(st->rrddim_root_index, rda->item);
+        rda->item = NULL;
+        rda->rd = NULL;
     }
 
-    rrdset_unlock(st);
+    rrdcontext_collected_rrdset(st);
 
     netdata_thread_enable_cancelability();
+
+    store_metric_collection_completed();
 }
 
+time_t rrdset_set_update_every(RRDSET *st, time_t update_every) {
+
+    internal_error(true, "RRDSET '%s' switching update every from %d to %d",
+                   rrdset_id(st), (int)st->update_every, (int)update_every);
+
+    time_t prev_update_every = st->update_every;
+    st->update_every = update_every;
+
+    // switch update every to the storage engine
+    RRDDIM *rd;
+    rrddim_foreach_read(rd, st) {
+        for (size_t tier = 0; tier < storage_tiers; tier++) {
+            if (rd->tiers[tier] && rd->tiers[tier]->db_collection_handle)
+                rd->tiers[tier]->collect_ops->change_collection_frequency(rd->tiers[tier]->db_collection_handle, (int)(st->rrdhost->db[tier].tier_grouping * st->update_every));
+        }
+
+        assert(rd->update_every == prev_update_every &&
+               "chart's update every differs from the update every of its dimensions");
+        rd->update_every = st->update_every;
+    }
+    rrddim_foreach_done(rd);
+
+    return prev_update_every;
+}
 
 // ----------------------------------------------------------------------------
 // compatibility layer for RRDSET files v019
@@ -1966,8 +2031,8 @@ struct rrdset_map_save_v019 {
     usec_t usec_since_last_update;                  // NEEDS TO BE UPDATED - maintained on load
     struct timeval last_updated;                    // NEEDS TO BE UPDATED - check to reset all - fixed on load
     struct timeval last_collected_time;             // ignored
-    long long collected_total;                      // NEEDS TO BE UPDATED - maintained on load
-    long long last_collected_total;                 // NEEDS TO BE UPDATED - maintained on load
+    long long collected_total;                      // ignored
+    long long last_collected_total;                 // ignored
     void *rrdfamily;                                // ignored
     void *rrdhost;                                  // ignored
     void *next;                                     // ignored
@@ -1991,8 +2056,6 @@ void rrdset_memory_file_update(RRDSET *st) {
     st_on_file->usec_since_last_update = st->usec_since_last_update;
     st_on_file->last_updated.tv_sec = st->last_updated.tv_sec;
     st_on_file->last_updated.tv_usec = st->last_updated.tv_usec;
-    st_on_file->collected_total = st->collected_total;
-    st_on_file->last_collected_total = st->last_collected_total;
 }
 
 const char *rrdset_cache_filename(RRDSET *st) {
@@ -2008,7 +2071,7 @@ void rrdset_memory_file_free(RRDSET *st) {
     rrdset_memory_file_update(st);
 
     struct rrdset_map_save_v019 *st_on_file = st->st_on_file;
-    munmap(st_on_file, st_on_file->memsize);
+    netdata_munmap(st_on_file, st_on_file->memsize);
 
     // remove the pointers from the RRDDIM
     st->st_on_file = NULL;
@@ -2047,8 +2110,8 @@ bool rrdset_memory_load_or_create_map_save(RRDSET *st, RRD_MEMORY_MODE memory_mo
         info("Initializing file '%s'.", fullfilename);
         memset(st_on_file, 0, size);
     }
-    else if(strncmp(st_on_file->id, st->id, RRD_ID_LENGTH_MAX_V019) != 0) {
-        error("File '%s' contents are not for chart '%s'. Clearing it.", fullfilename, st->id);
+    else if(strncmp(st_on_file->id, rrdset_id(st), RRD_ID_LENGTH_MAX_V019) != 0) {
+        error("File '%s' contents are not for chart '%s'. Clearing it.", fullfilename, rrdset_id(st));
         memset(st_on_file, 0, size);
     }
     else if(st_on_file->memsize != size || st_on_file->entries != st->entries) {
@@ -2084,8 +2147,6 @@ bool rrdset_memory_load_or_create_map_save(RRDSET *st, RRD_MEMORY_MODE memory_mo
     st->usec_since_last_update = st_on_file->usec_since_last_update;
     st->last_updated.tv_sec = st_on_file->last_updated.tv_sec;
     st->last_updated.tv_usec = st_on_file->last_updated.tv_usec;
-    st->collected_total = st_on_file->collected_total;
-    st->last_collected_total = st_on_file->last_collected_total;
 
     // link it to st
     st->st_on_file = st_on_file;
@@ -2094,7 +2155,7 @@ bool rrdset_memory_load_or_create_map_save(RRDSET *st, RRD_MEMORY_MODE memory_mo
     memset(st_on_file, 0, size);
 
     // set the values we need
-    strncpyz(st_on_file->id, st->id, RRD_ID_LENGTH_MAX_V019 + 1);
+    strncpyz(st_on_file->id, rrdset_id(st), RRD_ID_LENGTH_MAX_V019 + 1);
     strcpy(st_on_file->cache_filename, fullfilename);
     strcpy(st_on_file->magic, RRDSET_MAGIC_V019);
     st_on_file->memsize = size;