Core/DBLayer: Add QueueSize() method (#26733)

* Core/DBLayer: Add QueueSize() method

Add QueueSize() method to database objects (Login, Character and World) that returns how many tasks are queued.
Include the queue size of the 3 databases in ".server debug" command

* Make the code less threadsafe

* Send data to InfluxDB

* Update grafana dashboard

(cherry picked from commit 96dc110f4a353871ac74c82ff4b1bcc4c34156f3)

6 files changed, 268 insertions, 22 deletions

diff --git a/contrib/grafana/4_Performance_profiling.json b/contrib/grafana/4_Performance_profiling.json
index 65eff659ae8..af0440f2245 100644
--- a/contrib/grafana/4_Performance_profiling.json
+++ b/contrib/grafana/4_Performance_profiling.json
@@ -29,7 +29,7 @@
   "gnetId": null,
   "graphTooltip": 0,
   "id": 15,
-  "iteration": 1596541749733,
+  "iteration": 1626984445687,
   "links": [],
   "panels": [
     {
@@ -42,7 +42,7 @@
       "error": false,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -79,9 +79,10 @@
       "links": [],
       "nullPointMode": "connected",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 5,
       "points": false,
       "renderer": "flot",
@@ -193,7 +194,7 @@
       "datasource": null,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -224,9 +225,10 @@
       "linewidth": 2,
       "nullPointMode": "connected",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 2,
       "points": false,
       "renderer": "flot",
@@ -381,7 +383,7 @@
       "datasource": null,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -412,9 +414,10 @@
       "linewidth": 0,
       "nullPointMode": "connected",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 2,
       "points": false,
       "renderer": "flot",
@@ -530,7 +533,7 @@
       "datasource": null,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -561,9 +564,10 @@
       "linewidth": 2,
       "nullPointMode": "connected",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 2,
       "points": false,
       "renderer": "flot",
@@ -673,7 +677,7 @@
       "datasource": null,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -704,9 +708,10 @@
       "linewidth": 0,
       "nullPointMode": "connected",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 2,
       "points": false,
       "renderer": "flot",
@@ -816,7 +821,7 @@
       "datasource": null,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -849,9 +854,10 @@
       "linewidth": 2,
       "nullPointMode": "connected",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 2,
       "points": false,
       "renderer": "flot",
@@ -961,7 +967,7 @@
       "datasource": null,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -994,9 +1000,10 @@
       "linewidth": 2,
       "nullPointMode": "null",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 2,
       "points": true,
       "renderer": "flot",
@@ -1106,7 +1113,7 @@
       "datasource": null,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -1137,9 +1144,10 @@
       "linewidth": 1,
       "nullPointMode": "null",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 2,
       "points": false,
       "renderer": "flot",
@@ -1253,7 +1261,7 @@
       "datasource": null,
       "fieldConfig": {
         "defaults": {
-          "custom": {}
+          "links": []
         },
         "overrides": []
       },
@@ -1284,9 +1292,10 @@
       "linewidth": 1,
       "nullPointMode": "null",
       "options": {
-        "dataLinks": []
+        "alertThreshold": true
       },
       "percentage": false,
+      "pluginVersion": "8.0.3",
       "pointradius": 2,
       "points": false,
       "renderer": "flot",
@@ -1391,10 +1400,226 @@
         "align": false,
         "alignLevel": null
       }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": null,
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 39
+      },
+      "hiddenSeries": false,
+      "id": 17,
+      "legend": {
+        "avg": false,
+        "current": false,
+        "max": false,
+        "min": false,
+        "show": true,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 2,
+      "nullPointMode": "connected",
+      "options": {
+        "alertThreshold": true
+      },
+      "percentage": false,
+      "pluginVersion": "8.0.3",
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "alias": "Login DB",
+          "groupBy": [
+            {
+              "params": [
+                "$__interval"
+              ],
+              "type": "time"
+            },
+            {
+              "params": [
+                "null"
+              ],
+              "type": "fill"
+            }
+          ],
+          "measurement": "db_queue_login",
+          "orderByTime": "ASC",
+          "policy": "default",
+          "refId": "A",
+          "resultFormat": "time_series",
+          "select": [
+            [
+              {
+                "params": [
+                  "value"
+                ],
+                "type": "field"
+              },
+              {
+                "params": [],
+                "type": "max"
+              }
+            ]
+          ],
+          "tags": [
+            {
+              "key": "realm",
+              "operator": "=~",
+              "value": "/^$realm$/"
+            }
+          ]
+        },
+        {
+          "alias": "Character DB",
+          "groupBy": [
+            {
+              "params": [
+                "$__interval"
+              ],
+              "type": "time"
+            },
+            {
+              "params": [
+                "null"
+              ],
+              "type": "fill"
+            }
+          ],
+          "hide": false,
+          "measurement": "db_queue_character",
+          "orderByTime": "ASC",
+          "policy": "default",
+          "refId": "B",
+          "resultFormat": "time_series",
+          "select": [
+            [
+              {
+                "params": [
+                  "value"
+                ],
+                "type": "field"
+              },
+              {
+                "params": [],
+                "type": "max"
+              }
+            ]
+          ],
+          "tags": [
+            {
+              "key": "realm",
+              "operator": "=~",
+              "value": "/^$realm$/"
+            }
+          ]
+        },
+        {
+          "alias": "World DB",
+          "groupBy": [
+            {
+              "params": [
+                "$__interval"
+              ],
+              "type": "time"
+            },
+            {
+              "params": [
+                "null"
+              ],
+              "type": "fill"
+            }
+          ],
+          "hide": false,
+          "measurement": "db_queue_world",
+          "orderByTime": "ASC",
+          "policy": "default",
+          "refId": "C",
+          "resultFormat": "time_series",
+          "select": [
+            [
+              {
+                "params": [
+                  "value"
+                ],
+                "type": "field"
+              },
+              {
+                "params": [],
+                "type": "max"
+              }
+            ]
+          ],
+          "tags": [
+            {
+              "key": "realm",
+              "operator": "=~",
+              "value": "/^$realm$/"
+            }
+          ]
+        }
+      ],
+      "thresholds": [],
+      "timeFrom": null,
+      "timeRegions": [],
+      "timeShift": null,
+      "title": "Database queue",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "buckets": null,
+        "mode": "time",
+        "name": null,
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "$$hashKey": "object:102",
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        },
+        {
+          "$$hashKey": "object:103",
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false,
+        "alignLevel": null
+      }
     }
   ],
   "refresh": "1m",
-  "schemaVersion": 25,
+  "schemaVersion": 30,
   "style": "dark",
   "tags": [],
   "templating": {
@@ -1408,6 +1633,8 @@
         },
         "datasource": "Influx",
         "definition": "show tag values from events with key = realm",
+        "description": null,
+        "error": null,
         "hide": 0,
         "includeAll": false,
         "label": null,
@@ -1420,7 +1647,6 @@
         "skipUrlSync": false,
         "sort": 0,
         "tagValuesQuery": "",
-        "tags": [],
         "tagsQuery": "",
         "type": "query",
         "useTags": false
@@ -1447,5 +1673,5 @@
   "timezone": "",
   "title": "Performance profiling",
   "uid": "IRRL03nMk",
-  "version": 8
+  "version": 9
 }
\ No newline at end of file
diff --git a/src/common/Threading/ProducerConsumerQueue.h b/src/common/Threading/ProducerConsumerQueue.h
index 1341bd26747..778f434e9de 100644
--- a/src/common/Threading/ProducerConsumerQueue.h
+++ b/src/common/Threading/ProducerConsumerQueue.h
@@ -52,6 +52,11 @@ public:
         return _queue.empty();
     }
 
+    size_t Size() const
+    {
+        return _queue.size();
+    }
+
     bool Pop(T& value)
     {
         std::lock_guard<std::mutex> lock(_queueLock);
diff --git a/src/server/database/Database/DatabaseWorkerPool.cpp b/src/server/database/Database/DatabaseWorkerPool.cpp
index 043db148a1e..7aa1a1e46d1 100644
--- a/src/server/database/Database/DatabaseWorkerPool.cpp
+++ b/src/server/database/Database/DatabaseWorkerPool.cpp
@@ -415,6 +415,12 @@ void DatabaseWorkerPool<T>::Enqueue(SQLOperation* op)
 }
 
 template <class T>
+size_t DatabaseWorkerPool<T>::QueueSize() const
+{
+    return _queue->Size();
+}
+
+template <class T>
 T* DatabaseWorkerPool<T>::GetFreeConnection()
 {
 #ifdef TRINITY_DEBUG
diff --git a/src/server/database/Database/DatabaseWorkerPool.h b/src/server/database/Database/DatabaseWorkerPool.h
index 9852ded374e..66d5a55dffa 100644
--- a/src/server/database/Database/DatabaseWorkerPool.h
+++ b/src/server/database/Database/DatabaseWorkerPool.h
@@ -213,6 +213,8 @@ class DatabaseWorkerPool
 #endif
         }
 
+        size_t QueueSize() const;
+
     private:
         uint32 OpenConnections(InternalIndex type, uint8 numConnections);
 
diff --git a/src/server/scripts/Commands/cs_server.cpp b/src/server/scripts/Commands/cs_server.cpp
index 20b7961f13c..7306b73554c 100644
--- a/src/server/scripts/Commands/cs_server.cpp
+++ b/src/server/scripts/Commands/cs_server.cpp
@@ -249,6 +249,10 @@ public:
         handler->PSendSysMessage("Using %s DBC Locale as default. All available DBC locales: %s", localeNames[defaultLocale], availableLocales.c_str());
 
         handler->PSendSysMessage("Using World DB: %s", sWorld->GetDBVersion());
+
+        handler->PSendSysMessage("LoginDatabase queue size: %zu", LoginDatabase.QueueSize());
+        handler->PSendSysMessage("CharacterDatabase queue size: %zu", CharacterDatabase.QueueSize());
+        handler->PSendSysMessage("WorldDatabase queue size: %zu", WorldDatabase.QueueSize());
         return true;
     }
 
diff --git a/src/server/worldserver/Main.cpp b/src/server/worldserver/Main.cpp
index 96d81f98f17..1fe51079f6b 100644
--- a/src/server/worldserver/Main.cpp
+++ b/src/server/worldserver/Main.cpp
@@ -281,6 +281,9 @@ extern int main(int argc, char** argv)
     sMetric->Initialize(realm.Name, *ioContext, []()
     {
         TC_METRIC_VALUE("online_players", sWorld->GetPlayerCount());
+        TC_METRIC_VALUE("db_queue_login", LoginDatabase.QueueSize());
+        TC_METRIC_VALUE("db_queue_character", CharacterDatabase.QueueSize());
+        TC_METRIC_VALUE("db_queue_world", WorldDatabase.QueueSize());
     });
 
     TC_METRIC_EVENT("events", "Worldserver started", "");