1 files changed, 185 insertions, 22 deletions

diff --git a/database/engine/pagecache.c b/database/engine/pagecache.c
index cddbf9e1f..39f7642d0 100644
--- a/database/engine/pagecache.c
+++ b/database/engine/pagecache.c
@@ -3,6 +3,50 @@
 
 #include "rrdengine.h"
 
+ARAL page_descr_aral = {
+    .element_size = sizeof(struct rrdeng_page_descr),
+    .elements = 20000,
+    .filename = "page_descriptors",
+    .cache_dir = &netdata_configured_cache_dir,
+    .use_mmap = false,
+    .internal.initialized = false
+};
+
+void rrdeng_page_descr_aral_go_singlethreaded(void) {
+    page_descr_aral.internal.lockless = true;
+}
+void rrdeng_page_descr_aral_go_multithreaded(void) {
+    page_descr_aral.internal.lockless = false;
+}
+
+struct rrdeng_page_descr *rrdeng_page_descr_mallocz(void) {
+    struct rrdeng_page_descr *descr;
+    descr = arrayalloc_mallocz(&page_descr_aral);
+    return descr;
+}
+
+void rrdeng_page_descr_freez(struct rrdeng_page_descr *descr) {
+    arrayalloc_freez(&page_descr_aral, descr);
+}
+
+void rrdeng_page_descr_use_malloc(void) {
+    if(page_descr_aral.internal.initialized)
+        error("DBENGINE: cannot change ARAL allocation policy after it has been initialized.");
+    else
+        page_descr_aral.use_mmap = false;
+}
+
+void rrdeng_page_descr_use_mmap(void) {
+    if(page_descr_aral.internal.initialized)
+        error("DBENGINE: cannot change ARAL allocation policy after it has been initialized.");
+    else
+        page_descr_aral.use_mmap = true;
+}
+
+bool rrdeng_page_descr_is_mmap(void) {
+    return page_descr_aral.use_mmap;
+}
+
 /* Forward declarations */
 static int pg_cache_try_evict_one_page_unsafe(struct rrdengine_instance *ctx);
 
@@ -81,7 +125,7 @@ struct rrdeng_page_descr *pg_cache_create_descr(void)
 {
     struct rrdeng_page_descr *descr;
 
-    descr = mallocz(sizeof(*descr));
+    descr = rrdeng_page_descr_mallocz();
     descr->page_length = 0;
     descr->start_time = INVALID_TIME;
     descr->end_time = INVALID_TIME;
@@ -238,8 +282,7 @@ static void pg_cache_release_pages(struct rrdengine_instance *ctx, unsigned numb
  */
 unsigned long pg_cache_hard_limit(struct rrdengine_instance *ctx)
 {
-    /* it's twice the number of producers since we pin 2 pages per producer */
-    return ctx->max_cache_pages + 2 * (unsigned long)ctx->metric_API_max_producers;
+    return ctx->max_cache_pages + (unsigned long)ctx->metric_API_max_producers;
 }
 
 /*
@@ -248,8 +291,7 @@ unsigned long pg_cache_hard_limit(struct rrdengine_instance *ctx)
  */
 unsigned long pg_cache_soft_limit(struct rrdengine_instance *ctx)
 {
-    /* it's twice the number of producers since we pin 2 pages per producer */
-    return ctx->cache_pages_low_watermark + 2 * (unsigned long)ctx->metric_API_max_producers;
+    return ctx->cache_pages_low_watermark + (unsigned long)ctx->metric_API_max_producers;
 }
 
 /*
@@ -496,7 +538,7 @@ uint8_t pg_cache_punch_hole(struct rrdengine_instance *ctx, struct rrdeng_page_d
         (void)sleep_usec(1000); /* 1 msec */
     }
 destroy:
-    freez(descr);
+    rrdeng_page_descr_freez(descr);
     pg_cache_update_metric_times(page_index);
 
     return can_delete_metric;
@@ -1069,9 +1111,9 @@ pg_cache_lookup_next(struct rrdengine_instance *ctx, struct pg_cache_page_index
     int retry_count = 0;
     while (1) {
         descr = find_first_page_in_time_range(page_index, start_time, end_time);
-        if (NULL == descr || 0 == descr->page_length || retry_count == MAX_PAGE_CACHE_RETRY_WAIT) {
+        if (NULL == descr || 0 == descr->page_length || retry_count == default_rrdeng_page_fetch_retries) {
             /* non-empty page not found */
-            if (retry_count == MAX_PAGE_CACHE_RETRY_WAIT)
+            if (retry_count == default_rrdeng_page_fetch_retries)
                 error_report("Page cache timeout while waiting for page %p : returning FAIL", descr);
             uv_rwlock_rdunlock(&page_index->lock);
 
@@ -1117,7 +1159,7 @@ pg_cache_lookup_next(struct rrdengine_instance *ctx, struct pg_cache_page_index
         if (!(flags & RRD_PAGE_POPULATED))
             page_not_in_cache = 1;
 
-        if (pg_cache_timedwait_event_unsafe(descr, 1) == UV_ETIMEDOUT) {
+        if (pg_cache_timedwait_event_unsafe(descr, default_rrdeng_page_fetch_timeout) == UV_ETIMEDOUT) {
             error_report("Page cache timeout while waiting for page %p : retry count = %d", descr, retry_count);
             ++retry_count;
         }
@@ -1196,24 +1238,66 @@ void init_page_cache(struct rrdengine_instance *ctx)
     init_committed_page_index(ctx);
 }
 
+
+
+/*
+ * METRIC                                            # number
+ * 1. INDEX: JudyHS                                  # bytes
+ * 2. DATA: page_index                               # bytes
+ *
+ * PAGE (1 page of 1 metric)                         # number
+ * 1. INDEX AT METRIC: page_index->JudyL_array       # bytes
+ * 2. DATA: descr                                    # bytes
+ *
+ * PAGE CACHE (1 page of 1 metric at the cache)      # number
+ * 1. pg_cache_descr (if PG_CACHE_DESCR_ALLOCATED)   # bytes
+ * 2. data (if RRD_PAGE_POPULATED)                   # bytes
+ *
+ */
+
+
 void free_page_cache(struct rrdengine_instance *ctx)
 {
     struct page_cache *pg_cache = &ctx->pg_cache;
-    Word_t ret_Judy, bytes_freed = 0;
     Pvoid_t *PValue;
     struct pg_cache_page_index *page_index, *prev_page_index;
     Word_t Index;
     struct rrdeng_page_descr *descr;
     struct page_cache_descr *pg_cache_descr;
 
+    Word_t metrics_number      = 0,
+           metrics_bytes       = 0,
+           metrics_index_bytes = 0,
+           metrics_duration    = 0;
+
+    Word_t pages_number        = 0,
+           pages_bytes         = 0,
+           pages_index_bytes   = 0;
+
+    Word_t pages_size_per_type[256]  = { 0 },
+           pages_count_per_type[256] = { 0 };
+
+    Word_t cache_pages_number  = 0,
+           cache_pages_bytes   = 0,
+           cache_pages_data_bytes  = 0;
+
+    size_t points_in_db        = 0,
+           uncompressed_points_size = 0,
+           seconds_in_db       = 0,
+           single_point_pages  = 0;
+
+    Word_t pages_dirty_index_bytes = 0;
+
+    usec_t oldest_time_ut = LONG_MAX, latest_time_ut = 0;
+
     /* Free committed page index */
-    ret_Judy = JudyLFreeArray(&pg_cache->committed_page_index.JudyL_array, PJE0);
+    pages_dirty_index_bytes = JudyLFreeArray(&pg_cache->committed_page_index.JudyL_array, PJE0);
     fatal_assert(NULL == pg_cache->committed_page_index.JudyL_array);
-    bytes_freed += ret_Judy;
 
     for (page_index = pg_cache->metrics_index.last_page_index ;
          page_index != NULL ;
          page_index = prev_page_index) {
+
         prev_page_index = page_index->prev;
 
         /* Find first page in range */
@@ -1221,37 +1305,116 @@ void free_page_cache(struct rrdengine_instance *ctx)
         PValue = JudyLFirst(page_index->JudyL_array, &Index, PJE0);
         descr = unlikely(NULL == PValue) ? NULL : *PValue;
 
+        size_t metric_duration = 0;
+        size_t metric_update_every = 0;
+        size_t metric_single_point_pages = 0;
+
         while (descr != NULL) {
             /* Iterate all page descriptors of this metric */
 
             if (descr->pg_cache_descr_state & PG_CACHE_DESCR_ALLOCATED) {
+                cache_pages_number++;
+
                 /* Check rrdenglocking.c */
                 pg_cache_descr = descr->pg_cache_descr;
                 if (pg_cache_descr->flags & RRD_PAGE_POPULATED) {
                     dbengine_page_free(pg_cache_descr->page);
-                    bytes_freed += RRDENG_BLOCK_SIZE;
+                    cache_pages_data_bytes += RRDENG_BLOCK_SIZE;
                 }
                 rrdeng_destroy_pg_cache_descr(ctx, pg_cache_descr);
-                bytes_freed += sizeof(*pg_cache_descr);
+                cache_pages_bytes += sizeof(*pg_cache_descr);
             }
-            freez(descr);
-            bytes_freed += sizeof(*descr);
+
+            if(descr->start_time < oldest_time_ut)
+                oldest_time_ut = descr->start_time;
+
+            if(descr->end_time > latest_time_ut)
+                latest_time_ut = descr->end_time;
+
+            pages_size_per_type[descr->type] += descr->page_length;
+            pages_count_per_type[descr->type]++;
+
+            size_t points_in_page = (descr->page_length / PAGE_POINT_SIZE_BYTES(descr));
+            size_t page_duration  = ((descr->end_time - descr->start_time) / USEC_PER_SEC);
+            size_t update_every = (page_duration == 0) ? 1 : page_duration / (points_in_page - 1);
+
+            if (!page_duration && metric_update_every) {
+                page_duration = metric_update_every;
+                update_every = metric_update_every;
+            }
+            else if(page_duration)
+                metric_update_every = update_every;
+
+            uncompressed_points_size += descr->page_length;
+
+            if(page_duration > 0) {
+                page_duration = update_every * points_in_page;
+                metric_duration += page_duration;
+                seconds_in_db += page_duration;
+                points_in_db += descr->page_length / PAGE_POINT_SIZE_BYTES(descr);
+            }
+            else
+                metric_single_point_pages++;
+
+            rrdeng_page_descr_freez(descr);
+            pages_bytes += sizeof(*descr);
+            pages_number++;
 
             PValue = JudyLNext(page_index->JudyL_array, &Index, PJE0);
             descr = unlikely(NULL == PValue) ? NULL : *PValue;
         }
 
+        if(metric_single_point_pages && metric_update_every) {
+            points_in_db += metric_single_point_pages;
+            seconds_in_db += metric_update_every * metric_single_point_pages;
+            metric_duration += metric_update_every * metric_single_point_pages;
+        }
+        else
+            single_point_pages += metric_single_point_pages;
+
         /* Free page index */
-        ret_Judy = JudyLFreeArray(&page_index->JudyL_array, PJE0);
+        pages_index_bytes += JudyLFreeArray(&page_index->JudyL_array, PJE0);
         fatal_assert(NULL == page_index->JudyL_array);
-        bytes_freed += ret_Judy;
         freez(page_index);
-        bytes_freed += sizeof(*page_index);
+
+        metrics_number++;
+        metrics_bytes += sizeof(*page_index);
+        metrics_duration += metric_duration;
     }
     /* Free metrics index */
-    ret_Judy = JudyHSFreeArray(&pg_cache->metrics_index.JudyHS_array, PJE0);
+    metrics_index_bytes = JudyHSFreeArray(&pg_cache->metrics_index.JudyHS_array, PJE0);
     fatal_assert(NULL == pg_cache->metrics_index.JudyHS_array);
-    bytes_freed += ret_Judy;
 
-    info("Freed %lu bytes of memory from page cache.", bytes_freed);
+    if(!metrics_number) metrics_number = 1;
+    if(!pages_number) pages_number = 1;
+    if(!cache_pages_number) cache_pages_number = 1;
+    if(!points_in_db) points_in_db = 1;
+    if(latest_time_ut == oldest_time_ut) oldest_time_ut -= USEC_PER_SEC;
+
+    if(single_point_pages) {
+        long double avg_duration = (long double)seconds_in_db / points_in_db;
+        points_in_db += single_point_pages;
+        seconds_in_db += (size_t)(avg_duration * single_point_pages);
+    }
+
+    info("DBENGINE STATISTICS ON METRICS:"
+         " Metrics: %lu (structures %lu bytes - per metric %0.2f, index (HS) %lu bytes - per metric %0.2f bytes - duration %zu secs) |"
+         " Page descriptors: %lu (structures %lu bytes - per page %0.2f bytes, index (L) %lu bytes - per page %0.2f, dirty index %lu bytes). |"
+         " Page cache: %lu pages (structures %lu bytes - per page %0.2f bytes, data %lu bytes). |"
+         " Points in db %zu, uncompressed size of points database %zu bytes. |"
+         " Duration of all points %zu seconds, average point duration %0.2f seconds."
+         " Duration of the database %llu seconds, average metric duration %0.2f seconds, average metric lifetime %0.2f%%."
+         , metrics_number, metrics_bytes, (double)metrics_bytes/metrics_number, metrics_index_bytes, (double)metrics_index_bytes/metrics_number, metrics_duration
+         , pages_number, pages_bytes, (double)pages_bytes/pages_number, pages_index_bytes, (double)pages_index_bytes/pages_number, pages_dirty_index_bytes
+         , cache_pages_number, cache_pages_bytes, (double)cache_pages_bytes/cache_pages_number, cache_pages_data_bytes
+         , points_in_db, uncompressed_points_size
+         , seconds_in_db, (double)seconds_in_db/points_in_db
+         , (latest_time_ut - oldest_time_ut) / USEC_PER_SEC, (double)metrics_duration/metrics_number
+         , (double)metrics_duration/metrics_number * 100.0 / ((latest_time_ut - oldest_time_ut) / USEC_PER_SEC)
+         );
+
+    for(int i = 0; i < 256 ;i++) {
+        if(pages_count_per_type[i])
+            info("DBENGINE STATISTICS ON PAGE TYPES: page type %d total pages %lu, average page size %0.2f bytes", i, pages_count_per_type[i], (double)pages_size_per_type[i]/pages_count_per_type[i]);
+    }
 }