return the on disk size actually used by meilisearch

grafana-dashboards/dashboard.json

@@ -52,71 +52,6 @@
       "title": "Web application metrics",
       "type": "row"
     },
-    {
-      "datasource": {
-        "type": "prometheus"
-      },
-      "fieldConfig": {
-        "defaults": {
-          "color": {
-            "mode": "continuous-GrYlRd"
-          },
-          "decimals": 0,
-          "mappings": [],
-          "min": 0,
-          "thresholds": {
-            "mode": "absolute",
-            "steps": [
-              {
-                "color": "green",
-                "value": null
-              }
-            ]
-          },
-          "unit": "bytes"
-        },
-        "overrides": []
-      },
-      "gridPos": {
-        "h": 6,
-        "w": 4,
-        "x": 0,
-        "y": 1
-      },
-      "id": 2,
-      "interval": "5s",
-      "options": {
-        "colorMode": "value",
-        "graphMode": "area",
-        "justifyMode": "auto",
-        "orientation": "auto",
-        "reduceOptions": {
-          "calcs": [
-            "lastNotNull"
-          ],
-          "fields": "",
-          "values": false
-        },
-        "textMode": "auto"
-      },
-      "pluginVersion": "9.5.2",
-      "targets": [
-        {
-          "datasource": {
-            "type": "prometheus"
-          },
-          "editorMode": "builder",
-          "exemplar": true,
-          "expr": "meilisearch_db_size_bytes{job=\"meilisearch\", instance=\"$instance\"}",
-          "interval": "",
-          "legendFormat": "",
-          "range": true,
-          "refId": "A"
-        }
-      ],
-      "title": "Database Size",
-      "type": "stat"
-    },
     {
       "datasource": {
         "type": "prometheus"
@@ -145,7 +80,7 @@
       "gridPos": {
         "h": 6,
         "w": 4,
-        "x": 4,
+        "x": 0,
         "y": 1
       },
       "id": 22,
@@ -206,7 +141,7 @@
       "gridPos": {
         "h": 6,
         "w": 4,
-        "x": 8,
+        "x": 4,
         "y": 1
       },
       "id": 18,
@@ -431,10 +366,11 @@
         "type": "prometheus",
         "uid": "c4085c47-f6d3-45dd-b761-6809055bb749"
       },
+      "description": "",
       "fieldConfig": {
         "defaults": {
           "color": {
-            "mode": "continuous-YlBl"
+            "mode": "palette-classic"
           },
           "custom": {
             "axisCenteredZero": false,
@@ -443,7 +379,7 @@
             "axisPlacement": "auto",
             "barAlignment": 0,
             "drawStyle": "line",
-            "fillOpacity": 15,
+            "fillOpacity": 25,
             "gradientMode": "none",
             "hideFrom": {
               "legend": false,
@@ -456,18 +392,18 @@
             "scaleDistribution": {
               "type": "linear"
             },
-            "showPoints": "never",
+            "showPoints": "auto",
             "spanNulls": false,
             "stacking": {
               "group": "A",
-              "mode": "none"
+              "mode": "normal"
             },
             "thresholdsStyle": {
               "mode": "off"
             }
           },
-          "decimals": 2,
           "mappings": [],
+          "min": 0,
           "thresholds": {
             "mode": "absolute",
             "steps": [
@@ -480,7 +416,8 @@
                 "value": 80
               }
             ]
-          }
+          },
+          "unit": "bytes"
         },
         "overrides": []
       },
@@ -490,13 +427,13 @@
         "x": 0,
         "y": 7
       },
-      "id": 1,
+      "id": 2,
       "interval": "5s",
       "options": {
         "legend": {
           "calcs": [],
           "displayMode": "list",
-          "placement": "right",
+          "placement": "bottom",
           "showLegend": true
         },
         "tooltip": {
@@ -504,6 +441,7 @@
           "sort": "none"
         }
       },
+      "pluginVersion": "9.5.2",
       "targets": [
         {
           "datasource": {
@@ -511,14 +449,26 @@
           },
           "editorMode": "builder",
           "exemplar": true,
-          "expr": "rate(meilisearch_http_requests_total{instance=\"$instance\", job=\"meilisearch\"}[5m])",
+          "expr": "meilisearch_db_size_bytes{job=\"meilisearch\", instance=\"$instance\"}",
           "interval": "",
-          "legendFormat": "{{method}} {{path}}",
+          "legendFormat": "Database size on disk",
           "range": true,
-          "refId": "A"
+          "refId": "DB Size on disk"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "c4085c47-f6d3-45dd-b761-6809055bb749"
+          },
+          "editorMode": "builder",
+          "expr": "meilisearch_used_db_size_bytes{job=\"meilisearch\", instance=\"$instance\"}",
+          "hide": false,
+          "legendFormat": "Used bytes",
+          "range": true,
+          "refId": "Actual used bytes"
         }
       ],
-      "title": "HTTP requests per second (All Indexes)",
+      "title": "Database Size in bytes",
       "type": "timeseries"
     },
     {
@@ -616,6 +566,101 @@
       "title": "Mean response time (All Indexes)",
       "type": "timeseries"
     },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "c4085c47-f6d3-45dd-b761-6809055bb749"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "continuous-YlBl"
+          },
+          "custom": {
+            "axisCenteredZero": false,
+            "axisColorMode": "text",
+            "axisLabel": "",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 15,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 5,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "never",
+            "spanNulls": false,
+            "stacking": {
+              "group": "A",
+              "mode": "none"
+            },
+            "thresholdsStyle": {
+              "mode": "off"
+            }
+          },
+          "decimals": 2,
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 11,
+        "w": 12,
+        "x": 0,
+        "y": 18
+      },
+      "id": 1,
+      "interval": "5s",
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "list",
+          "placement": "right",
+          "showLegend": true
+        },
+        "tooltip": {
+          "mode": "single",
+          "sort": "none"
+        }
+      },
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus"
+          },
+          "editorMode": "builder",
+          "exemplar": true,
+          "expr": "rate(meilisearch_http_requests_total{instance=\"$instance\", job=\"meilisearch\"}[5m])",
+          "interval": "",
+          "legendFormat": "{{method}} {{path}}",
+          "range": true,
+          "refId": "A"
+        }
+      ],
+      "title": "HTTP requests per second (All Indexes)",
+      "type": "timeseries"
+    },
     {
       "cards": {},
       "color": {
@@ -648,7 +693,7 @@
         "h": 11,
         "w": 24,
         "x": 0,
-        "y": 18
+        "y": 29
       },
       "heatmap": {},
       "hideZeroBuckets": false,
@@ -790,7 +835,7 @@
         "h": 11,
         "w": 12,
         "x": 0,
-        "y": 29
+        "y": 40
       },
       "id": 23,
       "interval": "5s",
@@ -883,7 +928,7 @@
         "h": 11,
         "w": 12,
         "x": 12,
-        "y": 29
+        "y": 40
       },
       "id": 24,
       "interval": "5s",
@@ -976,7 +1021,7 @@
         "h": 11,
         "w": 12,
         "x": 0,
-        "y": 40
+        "y": 51
       },
       "id": 25,
       "interval": "5s",
@@ -1020,7 +1065,7 @@
         "h": 1,
         "w": 24,
         "x": 0,
-        "y": 51
+        "y": 62
       },
       "id": 12,
       "panels": [],
@@ -1098,7 +1143,7 @@
         "h": 11,
         "w": 12,
         "x": 0,
-        "y": 52
+        "y": 63
       },
       "id": 4,
       "interval": "5s",
@@ -1201,7 +1246,7 @@
         "h": 11,
         "w": 12,
         "x": 12,
-        "y": 52
+        "y": 63
       },
       "id": 5,
       "interval": "5s",
@@ -1323,6 +1368,6 @@
   "timezone": "",
   "title": "Meilisearch",
   "uid": "7wcZ94dnz",
-  "version": 3,
+  "version": 4,
   "weekStart": ""
 }

index-scheduler/src/index_mapper/mod.rs

@@ -90,6 +90,8 @@ pub struct IndexStats {
     pub number_of_documents: u64,
     /// Size of the index' DB, in bytes.
     pub database_size: u64,
+    /// Size of the index' DB, in bytes.
+    pub used_database_size: u64,
     /// Association of every field name with the number of times it occurs in the documents.
     pub field_distribution: FieldDistribution,
     /// Creation date of the index.
@@ -105,10 +107,10 @@ impl IndexStats {
     ///
     /// - rtxn: a RO transaction for the index, obtained from `Index::read_txn()`.
     pub fn new(index: &Index, rtxn: &RoTxn) -> Result<Self> {
-        let database_size = index.on_disk_size()?;
         Ok(IndexStats {
             number_of_documents: index.number_of_documents(rtxn)?,
-            database_size,
+            database_size: index.on_disk_size()?,
+            used_database_size: index.used_size()?,
             field_distribution: index.field_distribution(rtxn)?,
             created_at: index.created_at(rtxn)?,
             updated_at: index.updated_at(rtxn)?,

index-scheduler/src/lib.rs

@@ -554,10 +554,16 @@ impl IndexScheduler {
         &self.index_mapper.indexer_config
     }
 
+    /// Return the real database size (i.e.: The size **with** the free pages)
     pub fn size(&self) -> Result<u64> {
         Ok(self.env.real_disk_size()?)
     }
 
+    /// Return the used database size (i.e.: The size **without** the free pages)
+    pub fn used_size(&self) -> Result<u64> {
+        Ok(self.env.non_free_pages_size()?)
+    }
+
     /// Return the index corresponding to the name.
     ///
     /// * If the index wasn't opened before, the index will be opened.

meilisearch-auth/src/lib.rs

@@ -45,6 +45,11 @@ impl AuthController {
         self.store.size()
     }
 
+    /// Return the used size of the `AuthController` database in bytes.
+    pub fn used_size(&self) -> Result<u64> {
+        self.store.used_size()
+    }
+
     pub fn create_key(&self, create_key: CreateApiKey) -> Result<Key> {
         match self.store.get_api_key(create_key.uid)? {
             Some(_) => Err(AuthControllerError::ApiKeyAlreadyExists(create_key.uid.to_string())),

meilisearch-auth/src/store.rs

@@ -73,6 +73,11 @@ impl HeedAuthStore {
         Ok(self.env.real_disk_size()?)
     }
 
+    /// Return the number of bytes actually used in the database
+    pub fn used_size(&self) -> Result<u64> {
+        Ok(self.env.non_free_pages_size()?)
+    }
+
     pub fn set_drop_on_close(&mut self, v: bool) {
         self.should_close_on_drop = v;
     }

meilisearch/src/metrics.rs

@@ -23,7 +23,12 @@ lazy_static! {
     )
     .expect("Can't create a metric");
     pub static ref MEILISEARCH_DB_SIZE_BYTES: IntGauge =
-        register_int_gauge!(opts!("meilisearch_db_size_bytes", "Meilisearch Db Size In Bytes"))
+        register_int_gauge!(opts!("meilisearch_db_size_bytes", "Meilisearch DB Size In Bytes"))
+            .expect("Can't create a metric");
+    pub static ref MEILISEARCH_USED_DB_SIZE_BYTES: IntGauge = register_int_gauge!(opts!(
+        "meilisearch_used_db_size_bytes",
+        "Meilisearch Used DB Size In Bytes"
+    ))
     .expect("Can't create a metric");
     pub static ref MEILISEARCH_INDEX_COUNT: IntGauge =
         register_int_gauge!(opts!("meilisearch_index_count", "Meilisearch Index Count"))

meilisearch/src/routes/metrics.rs

@@ -31,6 +31,7 @@ pub async fn get_metrics(
     let response = create_all_stats((*index_scheduler).clone(), auth_controller, auth_filters)?;
 
     crate::metrics::MEILISEARCH_DB_SIZE_BYTES.set(response.database_size as i64);
+    crate::metrics::MEILISEARCH_USED_DB_SIZE_BYTES.set(response.used_database_size as i64);
     crate::metrics::MEILISEARCH_INDEX_COUNT.set(response.indexes.len() as i64);
 
     for (index, value) in response.indexes.iter() {

meilisearch/src/routes/mod.rs

@@ -231,6 +231,8 @@ pub async fn running() -> HttpResponse {
 #[serde(rename_all = "camelCase")]
 pub struct Stats {
     pub database_size: u64,
+    #[serde(skip)]
+    pub used_database_size: u64,
     #[serde(serialize_with = "time::serde::rfc3339::option::serialize")]
     pub last_update: Option<OffsetDateTime>,
     pub indexes: BTreeMap<String, indexes::IndexStats>,
@@ -259,6 +261,7 @@ pub fn create_all_stats(
     let mut last_task: Option<OffsetDateTime> = None;
     let mut indexes = BTreeMap::new();
     let mut database_size = 0;
+    let mut used_database_size = 0;
 
     for index_uid in index_scheduler.index_names()? {
         // Accumulate the size of all indexes, even unauthorized ones, so
@@ -266,6 +269,7 @@ pub fn create_all_stats(
         // See <https://github.com/meilisearch/meilisearch/pull/3541#discussion_r1126747643> for context.
         let stats = index_scheduler.index_stats(&index_uid)?;
         database_size += stats.inner_stats.database_size;
+        used_database_size += stats.inner_stats.used_database_size;
 
         if !filters.is_index_authorized(&index_uid) {
             continue;
@@ -278,10 +282,14 @@ pub fn create_all_stats(
     }
 
     database_size += index_scheduler.size()?;
+    used_database_size += index_scheduler.used_size()?;
     database_size += auth_controller.size()?;
-    database_size += index_scheduler.compute_update_file_size()?;
+    used_database_size += auth_controller.used_size()?;
+    let update_file_size = index_scheduler.compute_update_file_size()?;
+    database_size += update_file_size;
+    used_database_size += update_file_size;
 
-    let stats = Stats { database_size, last_update: last_task, indexes };
+    let stats = Stats { database_size, used_database_size, last_update: last_task, indexes };
     Ok(stats)
 }