Limit atomic operations for statistics (#15887)

Co-authored-by: Stelios Fragkakis <52996999+stelfrag@users.noreply.github.com>

4 files changed, 207 insertions, 81 deletions

diff --git a/daemon/global_statistics.c b/daemon/global_statistics.c
index ce8d414026..ab910e1890 100644
--- a/daemon/global_statistics.c
+++ b/daemon/global_statistics.c
@@ -2681,9 +2681,12 @@ static void dbengine2_statistics_charts(void) {
 
 static void update_strings_charts() {
     static RRDSET *st_ops = NULL, *st_entries = NULL, *st_mem = NULL;
-    static RRDDIM *rd_ops_inserts = NULL, *rd_ops_deletes = NULL, *rd_ops_searches = NULL, *rd_ops_duplications = NULL, *rd_ops_releases = NULL;
-    static RRDDIM *rd_entries_entries = NULL, *rd_entries_refs = NULL;
+    static RRDDIM *rd_ops_inserts = NULL, *rd_ops_deletes = NULL;
+    static RRDDIM *rd_entries_entries = NULL;
     static RRDDIM *rd_mem = NULL;
+#ifdef NETDATA_INTERNAL_CHECKS
+    static RRDDIM *rd_entries_refs = NULL, *rd_ops_releases = NULL,  *rd_ops_duplications = NULL, *rd_ops_searches = NULL;
+#endif
 
     size_t inserts, deletes, searches, entries, references, memory, duplications, releases;
 
@@ -2706,16 +2709,20 @@ static void update_strings_charts() {
 
         rd_ops_inserts      = rrddim_add(st_ops, "inserts",      NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
         rd_ops_deletes      = rrddim_add(st_ops, "deletes",      NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+#ifdef NETDATA_INTERNAL_CHECKS
         rd_ops_searches     = rrddim_add(st_ops, "searches",     NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
         rd_ops_duplications = rrddim_add(st_ops, "duplications", NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
         rd_ops_releases     = rrddim_add(st_ops, "releases",     NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+#endif
     }
 
     rrddim_set_by_pointer(st_ops, rd_ops_inserts,      (collected_number)inserts);
     rrddim_set_by_pointer(st_ops, rd_ops_deletes,      (collected_number)deletes);
+#ifdef NETDATA_INTERNAL_CHECKS
     rrddim_set_by_pointer(st_ops, rd_ops_searches,     (collected_number)searches);
     rrddim_set_by_pointer(st_ops, rd_ops_duplications, (collected_number)duplications);
     rrddim_set_by_pointer(st_ops, rd_ops_releases,     (collected_number)releases);
+#endif
     rrdset_done(st_ops);
 
     if (unlikely(!st_entries)) {
@@ -2734,11 +2741,15 @@ static void update_strings_charts() {
             , RRDSET_TYPE_AREA);
 
         rd_entries_entries  = rrddim_add(st_entries, "entries", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+#ifdef NETDATA_INTERNAL_CHECKS
         rd_entries_refs  = rrddim_add(st_entries, "references", NULL, 1, -1, RRD_ALGORITHM_ABSOLUTE);
+#endif
     }
 
     rrddim_set_by_pointer(st_entries, rd_entries_entries, (collected_number)entries);
+#ifdef NETDATA_INTERNAL_CHECKS
     rrddim_set_by_pointer(st_entries, rd_entries_refs, (collected_number)references);
+#endif
     rrdset_done(st_entries);
 
     if (unlikely(!st_mem)) {
@@ -2813,6 +2824,7 @@ struct dictionary_stats dictionary_stats_category_rrdhealth = { .name = "health"
 struct dictionary_stats dictionary_stats_category_functions = { .name = "functions" };
 struct dictionary_stats dictionary_stats_category_replication = { .name = "replication" };
 
+#ifdef DICT_WITH_STATS
 struct dictionary_categories {
     struct dictionary_stats *stats;
     const char *family;
@@ -3165,6 +3177,13 @@ static void update_dictionary_category_charts(struct dictionary_categories *c) {
     }
 }
 
+static void dictionary_statistics(void) {
+    for(int i = 0; dictionary_categories[i].stats ;i++) {
+        update_dictionary_category_charts(&dictionary_categories[i]);
+    }
+}
+#endif // DICT_WITH_STATS
+
 #ifdef NETDATA_TRACE_ALLOCATIONS
 
 struct memory_trace_data {
@@ -3304,12 +3323,6 @@ static void malloc_trace_statistics(void) {
 }
 #endif
 
-static void dictionary_statistics(void) {
-    for(int i = 0; dictionary_categories[i].stats ;i++) {
-        update_dictionary_category_charts(&dictionary_categories[i]);
-    }
-}
-
 // ---------------------------------------------------------------------------------------------------------------------
 // worker utilization
 
@@ -4171,8 +4184,10 @@ void *global_statistics_main(void *ptr)
         worker_is_busy(WORKER_JOB_STRINGS);
         update_strings_charts();
 
+#ifdef DICT_WITH_STATS
         worker_is_busy(WORKER_JOB_DICTIONARIES);
         dictionary_statistics();
+#endif
 
 #ifdef NETDATA_TRACE_ALLOCATIONS
         worker_is_busy(WORKER_JOB_MALLOC_TRACE);
diff --git a/libnetdata/dictionary/dictionary.c b/libnetdata/dictionary/dictionary.c
index 05da553444..1d695bae03 100644
--- a/libnetdata/dictionary/dictionary.c
+++ b/libnetdata/dictionary/dictionary.c
@@ -250,6 +250,7 @@ static inline void pointer_del(DICTIONARY *dict __maybe_unused, DICTIONARY_ITEM
 // ----------------------------------------------------------------------------
 // memory statistics
 
+#ifdef DICT_WITH_STATS
 static inline void DICTIONARY_STATS_PLUS_MEMORY(DICTIONARY *dict, size_t key_size, size_t item_size, size_t value_size) {
     if(key_size)
         __atomic_fetch_add(&dict->stats->memory.index, (long)JUDYHS_INDEX_SIZE_ESTIMATE(key_size), __ATOMIC_RELAXED);
@@ -260,6 +261,7 @@ static inline void DICTIONARY_STATS_PLUS_MEMORY(DICTIONARY *dict, size_t key_siz
     if(value_size)
         __atomic_fetch_add(&dict->stats->memory.values, (long)value_size, __ATOMIC_RELAXED);
 }
+
 static inline void DICTIONARY_STATS_MINUS_MEMORY(DICTIONARY *dict, size_t key_size, size_t item_size, size_t value_size) {
     if(key_size)
         __atomic_fetch_sub(&dict->stats->memory.index, (long)JUDYHS_INDEX_SIZE_ESTIMATE(key_size), __ATOMIC_RELAXED);
@@ -270,6 +272,10 @@ static inline void DICTIONARY_STATS_MINUS_MEMORY(DICTIONARY *dict, size_t key_si
     if(value_size)
         __atomic_fetch_sub(&dict->stats->memory.values, (long)value_size, __ATOMIC_RELAXED);
 }
+#else
+#define DICTIONARY_STATS_PLUS_MEMORY(dict, key_size, item_size, value_size) do {;} while(0)
+#define DICTIONARY_STATS_MINUS_MEMORY(dict, key_size, item_size, value_size) do {;} while(0)
+#endif
 
 // ----------------------------------------------------------------------------
 // callbacks registration
@@ -376,14 +382,21 @@ void dictionary_version_increment(DICTIONARY *dict) {
 // ----------------------------------------------------------------------------
 // internal statistics API
 
+#ifdef DICT_WITH_STATS
 static inline void DICTIONARY_STATS_SEARCHES_PLUS1(DICTIONARY *dict) {
     __atomic_fetch_add(&dict->stats->ops.searches, 1, __ATOMIC_RELAXED);
 }
+#else
+#define DICTIONARY_STATS_SEARCHES_PLUS1(dict) do {;} while(0)
+#endif
+
 static inline void DICTIONARY_ENTRIES_PLUS1(DICTIONARY *dict) {
+#ifdef DICT_WITH_STATS
     // statistics
     __atomic_fetch_add(&dict->stats->items.entries, 1, __ATOMIC_RELAXED);
     __atomic_fetch_add(&dict->stats->items.referenced, 1, __ATOMIC_RELAXED);
     __atomic_fetch_add(&dict->stats->ops.inserts, 1, __ATOMIC_RELAXED);
+#endif
 
     if(unlikely(is_dictionary_single_threaded(dict))) {
         dict->version++;
@@ -397,10 +410,13 @@ static inline void DICTIONARY_ENTRIES_PLUS1(DICTIONARY *dict) {
         __atomic_fetch_add(&dict->referenced_items, 1, __ATOMIC_RELAXED);
     }
 }
+
 static inline void DICTIONARY_ENTRIES_MINUS1(DICTIONARY *dict) {
+#ifdef DICT_WITH_STATS
     // statistics
     __atomic_fetch_add(&dict->stats->ops.deletes, 1, __ATOMIC_RELAXED);
     __atomic_fetch_sub(&dict->stats->items.entries, 1, __ATOMIC_RELAXED);
+#endif
 
     size_t entries; (void)entries;
     if(unlikely(is_dictionary_single_threaded(dict))) {
@@ -418,14 +434,19 @@ static inline void DICTIONARY_ENTRIES_MINUS1(DICTIONARY *dict) {
                    dict->creation_line,
                    dict->creation_file);
 }
+
 static inline void DICTIONARY_VALUE_RESETS_PLUS1(DICTIONARY *dict) {
+#ifdef DICT_WITH_STATS
     __atomic_fetch_add(&dict->stats->ops.resets, 1, __ATOMIC_RELAXED);
+#endif
 
     if(unlikely(is_dictionary_single_threaded(dict)))
         dict->version++;
     else
         __atomic_fetch_add(&dict->version, 1, __ATOMIC_RELAXED);
 }
+
+#ifdef DICT_WITH_STATS
 static inline void DICTIONARY_STATS_TRAVERSALS_PLUS1(DICTIONARY *dict) {
     __atomic_fetch_add(&dict->stats->ops.traversals, 1, __ATOMIC_RELAXED);
 }
@@ -476,9 +497,29 @@ static inline void DICTIONARY_STATS_DICT_DESTROY_QUEUED_MINUS1(DICTIONARY *dict)
 static inline void DICTIONARY_STATS_DICT_FLUSHES_PLUS1(DICTIONARY *dict) {
     __atomic_fetch_add(&dict->stats->ops.flushes, 1, __ATOMIC_RELAXED);
 }
+#else
+#define DICTIONARY_STATS_TRAVERSALS_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_WALKTHROUGHS_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_CHECK_SPINS_PLUS(dict, count) do {;} while(0)
+#define DICTIONARY_STATS_INSERT_SPINS_PLUS(dict, count) do {;} while(0)
+#define DICTIONARY_STATS_DELETE_SPINS_PLUS(dict, count) do {;} while(0)
+#define DICTIONARY_STATS_SEARCH_IGNORES_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_CALLBACK_INSERTS_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_CALLBACK_CONFLICTS_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_CALLBACK_REACTS_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_CALLBACK_DELETES_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_GARBAGE_COLLECTIONS_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_DICT_CREATIONS_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_DICT_DESTRUCTIONS_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_DICT_DESTROY_QUEUED_PLUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_DICT_DESTROY_QUEUED_MINUS1(dict) do {;} while(0)
+#define DICTIONARY_STATS_DICT_FLUSHES_PLUS1(dict) do {;} while(0)
+#endif
 
 static inline void DICTIONARY_REFERENCED_ITEMS_PLUS1(DICTIONARY *dict) {
+#ifdef DICT_WITH_STATS
     __atomic_fetch_add(&dict->stats->items.referenced, 1, __ATOMIC_RELAXED);
+#endif
 
     if(unlikely(is_dictionary_single_threaded(dict)))
         ++dict->referenced_items;
@@ -487,7 +528,9 @@ static inline void DICTIONARY_REFERENCED_ITEMS_PLUS1(DICTIONARY *dict) {
 }
 
 static inline void DICTIONARY_REFERENCED_ITEMS_MINUS1(DICTIONARY *dict) {
+#ifdef DICT_WITH_STATS
     __atomic_fetch_sub(&dict->stats->items.referenced, 1, __ATOMIC_RELAXED);
+#endif
 
     long int referenced_items; (void)referenced_items;
     if(unlikely(is_dictionary_single_threaded(dict)))
@@ -504,7 +547,9 @@ static inline void DICTIONARY_REFERENCED_ITEMS_MINUS1(DICTIONARY *dict) {
 }
 
 static inline void DICTIONARY_PENDING_DELETES_PLUS1(DICTIONARY *dict) {
+#ifdef DICT_WITH_STATS
     __atomic_fetch_add(&dict->stats->items.pending_deletion, 1, __ATOMIC_RELAXED);
+#endif
 
     if(unlikely(is_dictionary_single_threaded(dict)))
         ++dict->pending_deletion_items;
@@ -513,7 +558,9 @@ static inline void DICTIONARY_PENDING_DELETES_PLUS1(DICTIONARY *dict) {
 }
 
 static inline long int DICTIONARY_PENDING_DELETES_MINUS1(DICTIONARY *dict) {
+#ifdef DICT_WITH_STATS
     __atomic_fetch_sub(&dict->stats->items.pending_deletion, 1, __ATOMIC_RELEASE);
+#endif
 
     if(unlikely(is_dictionary_single_threaded(dict)))
         return --dict->pending_deletion_items;
@@ -977,7 +1024,7 @@ static int item_check_and_acquire_advanced(DICTIONARY *dict, DICTIONARY_ITEM *it
             DICTIONARY_REFERENCED_ITEMS_PLUS1(dict);
     }
 
-    if(unlikely(spins > 1 && dict->stats))
+    if(unlikely(spins > 1))
         DICTIONARY_STATS_CHECK_SPINS_PLUS(dict, spins - 1);
 
     return ret;
@@ -1022,7 +1069,7 @@ static inline int item_is_not_referenced_and_can_be_removed_advanced(DICTIONARY
         item->deleter_pid = gettid();
 #endif
 
-    if(unlikely(spins > 1 && dict->stats))
+    if(unlikely(spins > 1))
         DICTIONARY_STATS_DELETE_SPINS_PLUS(dict, spins - 1);
 
     return ret;
@@ -1535,22 +1582,6 @@ static inline void dict_item_release_and_check_if_it_is_deleted_and_can_be_remov
 }
 
 static bool dict_item_del(DICTIONARY *dict, const char *name, ssize_t name_len) {
-    if(unlikely(!name || !*name)) {
-        internal_error(
-            true,
-            "DICTIONARY: attempted to %s() without a name on a dictionary created from %s() %zu@%s.",
-            __FUNCTION__,
-            dict->creation_function,
-            dict->creation_line,
-            dict->creation_file);
-        return false;
-    }
-
-    if(unlikely(is_dictionary_destroyed(dict))) {
-        internal_error(true, "DICTIONARY: attempted to dictionary_del() on a destroyed dictionary");
-        return false;
-    }
-
     if(name_len == -1)
         name_len = (ssize_t)strlen(name) + 1; // we need the terminating null too
 
@@ -1695,7 +1726,7 @@ static DICTIONARY_ITEM *dict_item_add_or_reset_value_and_acquire(DICTIONARY *dic
     } while(!item);
 
 
-    if(unlikely(spins > 0 && dict->stats))
+    if(unlikely(spins > 0))
         DICTIONARY_STATS_INSERT_SPINS_PLUS(dict, spins);
 
     if(is_master_dictionary(dict) && added_or_updated)
@@ -2064,11 +2095,15 @@ void dictionary_flush(DICTIONARY *dict) {
     if(unlikely(!dict))
         return;
 
-    void *value;
-    dfe_start_write(dict, value) {
-        dictionary_del_advanced(dict, item_get_name(value_dfe.item), (ssize_t)item_get_name_len(value_dfe.item) + 1);
+    ll_recursive_lock(dict, DICTIONARY_LOCK_WRITE);
+
+    DICTIONARY_ITEM *item, *next = NULL;
+    for(item = dict->items.list; item ;item = next) {
+        next = item->next;
+        dict_item_del(dict, item_get_name(item), (ssize_t) item_get_name_len(item) + 1);
     }
-    dfe_done(value);
+
+    ll_recursive_unlock(dict, DICTIONARY_LOCK_WRITE);
 
     DICTIONARY_STATS_DICT_FLUSHES_PLUS1(dict);
 }
@@ -2251,6 +2286,12 @@ bool dictionary_del_advanced(DICTIONARY *dict, const char *name, ssize_t name_le
         return false;
 
     api_internal_check(dict, NULL, false, true);
+
+    if(unlikely(is_dictionary_destroyed(dict))) {
+        internal_error(true, "DICTIONARY: attempted to delete item on a destroyed dictionary");
+        return false;
+    }
+
     return dict_item_del(dict, name, name_len);
 }
 
@@ -2260,6 +2301,8 @@ bool dictionary_del_advanced(DICTIONARY *dict, const char *name, ssize_t name_le
 void *dictionary_foreach_start_rw(DICTFE *dfe, DICTIONARY *dict, char rw) {
     if(unlikely(!dfe || !dict)) return NULL;
 
+    DICTIONARY_STATS_TRAVERSALS_PLUS1(dict);
+
     if(unlikely(is_dictionary_destroyed(dict))) {
         internal_error(true, "DICTIONARY: attempted to dictionary_foreach_start_rw() on a destroyed dictionary");
         dfe->counter = 0;
@@ -2275,8 +2318,6 @@ void *dictionary_foreach_start_rw(DICTFE *dfe, DICTIONARY *dict, char rw) {
     dfe->locked = true;
     ll_recursive_lock(dict, dfe->rw);
 
-    DICTIONARY_STATS_TRAVERSALS_PLUS1(dict);
-
     // get the first item from the list
     DICTIONARY_ITEM *item = dict->items.list;
 
@@ -3129,6 +3170,9 @@ struct thread_unittest {
     int join;
     DICTIONARY *dict;
     int dups;
+
+    netdata_thread_t thread;
+    struct dictionary_stats stats;
 };
 
 static void *unittest_dict_thread(void *arg) {
@@ -3140,46 +3184,59 @@ static void *unittest_dict_thread(void *arg) {
         DICT_ITEM_CONST DICTIONARY_ITEM *item =
             dictionary_set_and_acquire_item_advanced(tu->dict, "dict thread checking 1234567890",
                                                      -1, NULL, 0, NULL);
-
+        tu->stats.ops.inserts++;
 
         dictionary_get(tu->dict, dictionary_acquired_item_name(item));
+        tu->stats.ops.searches++;
 
         void *t1;
         dfe_start_write(tu->dict, t1) {
 
             // this should delete the referenced item
             dictionary_del(tu->dict, t1_dfe.name);
+            tu->stats.ops.deletes++;
 
             void *t2;
             dfe_start_write(tu->dict, t2) {
                 // this should add another
                 dictionary_set(tu->dict, t2_dfe.name, NULL, 0);
+                tu->stats.ops.inserts++;
 
                 dictionary_get(tu->dict, dictionary_acquired_item_name(item));
+                tu->stats.ops.searches++;
 
                 // and this should delete it again
                 dictionary_del(tu->dict, t2_dfe.name);
+                tu->stats.ops.deletes++;
             }
             dfe_done(t2);
+            tu->stats.ops.traversals++;
 
             // this should fail to add it
             dictionary_set(tu->dict, t1_dfe.name, NULL, 0);
+            tu->stats.ops.inserts++;
+
             dictionary_del(tu->dict, t1_dfe.name);
+            tu->stats.ops.deletes++;
         }
         dfe_done(t1);
+        tu->stats.ops.traversals++;
 
         for(int i = 0; i < tu->dups ; i++) {
             dictionary_acquired_item_dup(tu->dict, item);
             dictionary_get(tu->dict, dictionary_acquired_item_name(item));
+            tu->stats.ops.searches++;
         }
 
         for(int i = 0; i < tu->dups ; i++) {
             dictionary_acquired_item_release(tu->dict, item);
             dictionary_del(tu->dict, dictionary_acquired_item_name(item));
+            tu->stats.ops.deletes++;
         }
 
         dictionary_acquired_item_release(tu->dict, item);
         dictionary_del(tu->dict, "dict thread checking 1234567890");
+        tu->stats.ops.deletes++;
 
         // test concurrent deletions and flushes
         {
@@ -3189,16 +3246,19 @@ static void *unittest_dict_thread(void *arg) {
                 for (int i = 0; i < 1000; i++) {
                     snprintfz(buf, 256, "del/flush test %d", i);
                     dictionary_set(tu->dict, buf, NULL, 0);
+                    tu->stats.ops.inserts++;
                 }
 
                 for (int i = 0; i < 1000; i++) {
                     snprintfz(buf, 256, "del/flush test %d", i);
                     dictionary_del(tu->dict, buf);
+                    tu->stats.ops.deletes++;
                 }
             }
             else {
                 for (int i = 0; i < 10; i++) {
                     dictionary_flush(tu->dict);
+                    tu->stats.ops.flushes++;
                 }
             }
         }
@@ -3208,47 +3268,75 @@ static void *unittest_dict_thread(void *arg) {
 }
 
 static int dictionary_unittest_threads() {
-
-    struct thread_unittest tu = {
-        .join = 0,
-        .dict = NULL,
-        .dups = 1,
-    };
-
-    // threads testing of dictionary
-    tu.dict = dictionary_create(DICT_OPTION_DONT_OVERWRITE_VALUE);
     time_t seconds_to_run = 5;
     int threads_to_create = 2;
+
+    struct thread_unittest tu[threads_to_create];
+    memset(tu, 0, sizeof(struct thread_unittest) * threads_to_create);
+
     fprintf(
-        stderr,
-        "\nChecking dictionary concurrency with %d threads for %lld seconds...\n",
-        threads_to_create,
-        (long long)seconds_to_run);
+            stderr,
+            "\nChecking dictionary concurrency with %d threads for %lld seconds...\n",
+            threads_to_create,
+            (long long)seconds_to_run);
+
+    // threads testing of dictionary
+    struct dictionary_stats stats = {};
+    tu[0].join = 0;
+    tu[0].dups = 1;
+    tu[0].dict = dictionary_create_advanced(DICT_OPTION_DONT_OVERWRITE_VALUE, &stats, 0);
 
-    netdata_thread_t threads[threads_to_create];
-    tu.join = 0;
     for (int i = 0; i < threads_to_create; i++) {
+        if(i)
+            tu[i] = tu[0];
+
         char buf[100 + 1];
         snprintf(buf, 100, "dict%d", i);
         netdata_thread_create(
-            &threads[i],
+            &tu[i].thread,
             buf,
             NETDATA_THREAD_OPTION_DONT_LOG | NETDATA_THREAD_OPTION_JOINABLE,
             unittest_dict_thread,
-            &tu);
+            &tu[i]);
     }
+
     sleep_usec(seconds_to_run * USEC_PER_SEC);
 
-    __atomic_store_n(&tu.join, 1, __ATOMIC_RELAXED);
     for (int i = 0; i < threads_to_create; i++) {
+        __atomic_store_n(&tu[i].join, 1, __ATOMIC_RELAXED);
+
         void *retval;
-        netdata_thread_join(threads[i], &retval);
+        netdata_thread_join(tu[i].thread, &retval);
+
+        if(i) {
+            tu[0].stats.ops.inserts += tu[i].stats.ops.inserts;
+            tu[0].stats.ops.deletes += tu[i].stats.ops.deletes;
+            tu[0].stats.ops.searches += tu[i].stats.ops.searches;
+            tu[0].stats.ops.flushes += tu[i].stats.ops.flushes;
+            tu[0].stats.ops.traversals += tu[i].stats.ops.traversals;
+        }
     }
 
     fprintf(stderr,
-            "inserts %zu"
+            "CALLS : inserts %zu"
             ", deletes %zu"
             ", searches %zu"
+            ", traversals %zu"
+            ", flushes %zu"
+            "\n",
+            tu[0].stats.ops.inserts,
+            tu[0].stats.ops.deletes,
+            tu[0].stats.ops.searches,
+            tu[0].stats.ops.traversals,
+            tu[0].stats.ops.flushes
+    );
+
+#ifdef DICT_WITH_STATS
+    fprintf(stderr,
+            "ACTUAL: inserts %zu"
+            ", deletes %zu"
+            ", searches %zu"
+            ", traversals %zu"
             ", resets %zu"
             ", flushes %zu"
             ", entries %d"
@@ -3259,22 +3347,23 @@ static int dictionary_unittest_threads() {
             ", delete spins %zu"
             ", search ignores %zu"
             "\n",
-            tu.dict->stats->ops.inserts,
-            tu.dict->stats->ops.deletes,
-            tu.dict->stats->ops.searches,
-            tu.dict->stats->ops.resets,
-            tu.dict->stats->ops.flushes,
-            tu.dict->entries,
-            tu.dict->referenced_items,
-            tu.dict->pending_deletion_items,
-            tu.dict->stats->spin_locks.use_spins,
-            tu.dict->stats->spin_locks.insert_spins,
-            tu.dict->stats->spin_locks.delete_spins,
-            tu.dict->stats->spin_locks.search_spins
+            stats.ops.inserts,
+            stats.ops.deletes,
+            stats.ops.searches,
+            stats.ops.traversals,
+            stats.ops.resets,
+            stats.ops.flushes,
+            tu[0].dict->entries,
+            tu[0].dict->referenced_items,
+            tu[0].dict->pending_deletion_items,
+            stats.spin_locks.use_spins,
+            stats.spin_locks.insert_spins,
+            stats.spin_locks.delete_spins,
+            stats.spin_locks.search_spins
     );
-    dictionary_destroy(tu.dict);
-    tu.dict = NULL;
+#endif
 
+    dictionary_destroy(tu[0].dict);
     return 0;
 }
 
@@ -3407,6 +3496,7 @@ static int dictionary_unittest_view_threads() {
     netdata_thread_join(view_thread, &retval);
     netdata_thread_join(master_thread, &retval);
 
+#ifdef DICT_WITH_STATS
     fprintf(stderr,
             "MASTER: inserts %zu"
             ", deletes %zu"
@@ -3457,6 +3547,8 @@ static int dictionary_unittest_view_threads() {
             stats_view.spin_locks.delete_spins,
             stats_view.spin_locks.search_spins
     );
+#endif
+
     dictionary_destroy(tv.master);
     dictionary_destroy(tv.view);
 
diff --git a/libnetdata/dictionary/dictionary.h b/libnetdata/dictionary/dictionary.h
index eea14d3fae..72efe1d038 100644
--- a/libnetdata/dictionary/dictionary.h
+++ b/libnetdata/dictionary/dictionary.h
@@ -35,6 +35,10 @@
  *
  */
 
+#ifdef NETDATA_INTERNAL_CHECKS
+#define DICT_WITH_STATS 1
+#endif
+
 #ifdef DICTIONARY_INTERNALS
 #define DICTFE_CONST
 #define DICT_ITEM_CONST
@@ -92,7 +96,7 @@ struct dictionary_stats {
 
     // memory
     struct {
-        long index;               // bytes of keys indexed (indication of the index size)
+        long index;                 // bytes of keys indexed (indication of the index size)
         long values;                // bytes of caller structures
         long dict;                  // bytes of the structures dictionary needs
     } memory;
diff --git a/libnetdata/string/string.c b/libnetdata/string/string.c
index 373d0c24c5..c76154e400 100644
--- a/libnetdata/string/string.c
+++ b/libnetdata/string/string.c
@@ -28,19 +28,22 @@ static struct string_partition {
 
     Pvoid_t JudyHSArray;        // the Judy array - hashtable
 
-    size_t searches;            // the number of successful searches in the index
-    size_t duplications;        // when a string is referenced
-    size_t releases;            // when a string is unreferenced
-
     size_t inserts;             // the number of successful inserts to the index
     size_t deletes;             // the number of successful deleted from the index
 
     long int entries;           // the number of entries in the index
-    long int active_references; // the number of active references alive
     long int memory;            // the memory used, without the JudyHS index
 
 #ifdef NETDATA_INTERNAL_CHECKS
     // internal statistics
+
+    struct {
+        size_t searches;            // the number of successful searches in the index
+        size_t releases;            // when a string is unreferenced
+        size_t duplications;        // when a string is referenced
+        long int active_references; // the number of active references alive
+    } atomic;
+
     size_t found_deleted_on_search;
     size_t found_available_on_search;
     size_t found_deleted_on_insert;
@@ -51,14 +54,15 @@ static struct string_partition {
 } string_base[STRING_PARTITIONS] = { 0 };
 
 #ifdef NETDATA_INTERNAL_CHECKS
+#define string_stats_atomic_increment(partition, var) __atomic_add_fetch(&string_base[partition].atomic.var, 1, __ATOMIC_RELAXED)
+#define string_stats_atomic_decrement(partition, var) __atomic_sub_fetch(&string_base[partition].atomic.var, 1, __ATOMIC_RELAXED)
 #define string_internal_stats_add(partition, var, val) __atomic_add_fetch(&string_base[partition].var, val, __ATOMIC_RELAXED)
 #else
+#define string_stats_atomic_increment(partition, var) do {;} while(0)
+#define string_stats_atomic_decrement(partition, var) do {;} while(0)
 #define string_internal_stats_add(partition, var, val) do {;} while(0)
 #endif
 
-#define string_stats_atomic_increment(partition, var) __atomic_add_fetch(&string_base[partition].var, 1, __ATOMIC_RELAXED)
-#define string_stats_atomic_decrement(partition, var) __atomic_sub_fetch(&string_base[partition].var, 1, __ATOMIC_RELAXED)
-
 void string_statistics(size_t *inserts, size_t *deletes, size_t *searches, size_t *entries, size_t *references, size_t *memory, size_t *duplications, size_t *releases) {
     if (inserts) *inserts = 0;
     if (deletes) *deletes = 0;
@@ -72,12 +76,15 @@ void string_statistics(size_t *inserts, size_t *deletes, size_t *searches, size_
     for(size_t i = 0; i < STRING_PARTITIONS ;i++) {
         if (inserts)        *inserts        += string_base[i].inserts;
         if (deletes)        *deletes        += string_base[i].deletes;
-        if (searches)       *searches       += string_base[i].searches;
         if (entries)        *entries        += (size_t) string_base[i].entries;
-        if (references)     *references     += (size_t) string_base[i].active_references;
         if (memory)         *memory         += (size_t) string_base[i].memory;
-        if (duplications)   *duplications   += string_base[i].duplications;
-        if (releases)       *releases       += string_base[i].releases;
+
+#ifdef NETDATA_INTERNAL_CHECKS
+        if (searches)       *searches       += string_base[i].atomic.searches;
+        if (references)     *references     += (size_t) string_base[i].atomic.active_references;
+        if (duplications)   *duplications   += string_base[i].atomic.duplications;
+        if (releases)       *releases       += string_base[i].atomic.releases;
+#endif
     }
 }
 
@@ -85,7 +92,9 @@ void string_statistics(size_t *inserts, size_t *deletes, size_t *searches, size_
 #define string_entry_release(se) __atomic_sub_fetch(&((se)->refcount), 1, __ATOMIC_SEQ_CST);
 
 static inline bool string_entry_check_and_acquire(STRING *se) {
+#ifdef NETDATA_INTERNAL_CHECKS
     uint8_t partition = string_partition(se);
+#endif
 
     REFCOUNT expected, desired, count = 0;
 
@@ -125,7 +134,9 @@ STRING *string_dup(STRING *string) {
 
     string_entry_acquire(string);
 
+#ifdef NETDATA_INTERNAL_CHECKS
     uint8_t partition = string_partition(string);
+#endif
 
     // statistics
     string_stats_atomic_increment(partition, active_references);
@@ -275,7 +286,9 @@ static inline void string_index_delete(STRING *string) {
 STRING *string_strdupz(const char *str) {
     if(unlikely(!str || !*str)) return NULL;
 
+#ifdef NETDATA_INTERNAL_CHECKS
     uint8_t partition = string_partition_str(str);
+#endif
 
     size_t length = strlen(str) + 1;
     STRING *string = string_index_search(str, length);
@@ -297,7 +310,9 @@ STRING *string_strdupz(const char *str) {
 void string_freez(STRING *string) {
     if(unlikely(!string)) return;
 
+#ifdef NETDATA_INTERNAL_CHECKS
     uint8_t partition = string_partition(string);
+#endif
     REFCOUNT refcount = string_entry_release(string);
 
 #ifdef NETDATA_INTERNAL_CHECKS