Implement real time statistic visualization (#16956)

Docs at https://trinitycore.atlassian.net/wiki/display/tc/Monitoring+a+TrinityCore+server

* Common/Graphs: Initial proof of concept

* Move influx db code to its own class

* Reuse the same socket

* Allow to log values of different categories

* Allow to log events

* Pass the timestamp to influxdb

* Send events in batches

* Send data async

* Log server shutdown.
Fix memory leak.

* Allow to enable/disable Stats in the settings and at runtime

* Read interval between each batch send from config

* Add InfluxDB connection info to configs

* Move each event category to its own table

* Log pathfinding queries

* Move categories table initialization to constructor using enum as key to avoid assigning the table name to the wrong enum value

* Log player login/logout events.
Pass the hostname correctly in the HTTP request.

* Fix linux build

* Handle "Connection: close" HTTP header, reconnecting on next scheduled send.
Disable StatsLogger if connection fails, logging the error.

* Add an enum for categories of logged values, it's still possible to pass a string instead of the enum.

* Don't log the whole batchedData when InfluxDB returns an error, it's too long and unreadable on console.

* Allow to call a function at a specified interval in thread-safe World::Update() context to log data like player count.

* Log map tile load/unload

* Core/StatsLogger: Allow logging more value types other than ints

https://docs.influxdata.com/influxdb/v0.10/write_protocols/write_syntax/

* Fix a typo in string escape of StatsLogger

* Yet more fixes to the escaping in FormatInfluxDBValue

* DB/Gameobject: Fix respawn time of few Quest GameObjects

By Tauriella, closes #16701

* DB/Misc: Fix some engrish

By tkrokli closes #16648

* Tools/MMaps: Add format library linking to mmaps_generator

(Very) partial cherry pick of ed75b0649add23e082976fa4e5d504bc0c312602

* Core/StatsLogger: Simplify code

Convert values and categories arrays to maps initialized in-place
Remove constructor and destructor

* Core/StatsLogger: Add realm name to the event and value tags

* Log amount of processed packet of each session

* Apply recent singleton changes to sStatsLogger too

* Fix influxdb data format if no realm name is present

* Remove unneeded newlines from request body, fixes response 400 from InfluxDB 0.10

* Rename Reporting folder to Metric

* Rename StatsLogger to Metric

* Rename InfluxDB configs to Metric

* Add Grafana dashboards

* Add a random annoying macro

* Move string formatting to Metric::SendBatch(), reducing performance footprint of Metric::LogEvent() and Metric::LogValue()

* Update grafana graphs refresing tags on load and showing now-15m data, refreshing every minute. These settings can be modified in grafana.

* Rename MetricData fields

* Contrib/Grafana: Rename dashboard files

* Contrib/Grafana: Replace hardcoded Windows/Ubuntu realm names by the default, Trinity

* Config/Worldserver: Add missing section to the index

* Contrib/Grafana: Add singlestat panels with current online players, update diff averages (1 min, 5 mins and 15 mins)

http://i.imgur.com/Zi8lfvS.png

* Core/Metric: Replace the enums MetricEventCategory and MetricValueCategory by strings

For the sake of simplicity and less recompile time when adding new metrics, similar to how TC_LOG_* works

* Contrib/Grafana: Display the current number of online players and not its average

Closes #15075
(cherry picked from commit 3ae10160820782d039c3449107960108fb3a63b9)

# Conflicts:
#	src/server/game/Server/WorldSession.cpp
#	src/server/game/World/World.cpp
#	src/server/worldserver/Main.cpp

4 files changed, 19 insertions, 0 deletions

diff --git a/src/server/game/Handlers/CharacterHandler.cpp b/src/server/game/Handlers/CharacterHandler.cpp
index ee1d69571f0..e4b03ed79c7 100644
--- a/src/server/game/Handlers/CharacterHandler.cpp
+++ b/src/server/game/Handlers/CharacterHandler.cpp
@@ -54,6 +54,7 @@
 #include "World.h"
 #include "WorldPacket.h"
 #include "WorldSession.h"
+#include "Metric.h"
 
 class LoginQueryHolder : public SQLQueryHolder
 {
@@ -1147,6 +1148,8 @@ void WorldSession::HandlePlayerLogin(LoginQueryHolder* holder)
 
     sScriptMgr->OnPlayerLogin(pCurrChar, firstLogin);
 
+    TC_METRIC_EVENT("player_events", "Login", pCurrChar->GetName());
+
     delete holder;
 }
 
diff --git a/src/server/game/Movement/PathGenerator.cpp b/src/server/game/Movement/PathGenerator.cpp
index fe09aa26af2..39087269e54 100644
--- a/src/server/game/Movement/PathGenerator.cpp
+++ b/src/server/game/Movement/PathGenerator.cpp
@@ -26,6 +26,7 @@
 #include "DisableMgr.h"
 #include "DetourCommon.h"
 #include "DetourNavMeshQuery.h"
+#include "Metric.h"
 
 ////////////////// PathGenerator //////////////////
 PathGenerator::PathGenerator(const Unit* owner) :
@@ -62,6 +63,8 @@ bool PathGenerator::CalculatePath(float destX, float destY, float destZ, bool fo
     if (!Trinity::IsValidMapCoord(destX, destY, destZ) || !Trinity::IsValidMapCoord(x, y, z))
         return false;
 
+    TC_METRIC_EVENT("mmap_events", "CalculatePath", "");
+
     G3D::Vector3 dest(destX, destY, destZ);
     SetEndPosition(dest);
 
diff --git a/src/server/game/Server/WorldSession.cpp b/src/server/game/Server/WorldSession.cpp
index 41141148922..c11c85aaffa 100644
--- a/src/server/game/Server/WorldSession.cpp
+++ b/src/server/game/Server/WorldSession.cpp
@@ -51,6 +51,7 @@
 #include "BattlePetMgr.h"
 #include "PacketUtilities.h"
 #include "CollectionMgr.h"
+#include "Metric.h"
 
 #include <zlib.h>
 
@@ -456,6 +457,8 @@ bool WorldSession::Update(uint32 diff, PacketFilter& updater)
             break;
     }
 
+    TC_METRIC_VALUE("processed_packets", processedPackets);
+
     _recvQueue.readd(requeuePackets.begin(), requeuePackets.end());
 
     if (m_Socket[CONNECTION_TYPE_REALM] && m_Socket[CONNECTION_TYPE_REALM]->IsOpen() && _warden)
@@ -614,6 +617,8 @@ void WorldSession::LogoutPlayer(bool save)
         //! Call script hook before deletion
         sScriptMgr->OnPlayerLogout(_player);
 
+        TC_METRIC_EVENT("player_events", "Logout", _player->GetName());
+
         //! Remove the player from the world
         // the player may not be in the world when logging out
         // e.g if he got disconnected during a transfer to another map
diff --git a/src/server/game/World/World.cpp b/src/server/game/World/World.cpp
index 61e1755b4e4..5513c8e94dd 100644
--- a/src/server/game/World/World.cpp
+++ b/src/server/game/World/World.cpp
@@ -63,6 +63,7 @@
 #include "SkillDiscovery.h"
 #include "SkillExtraItems.h"
 #include "SmartAI.h"
+#include "Metric.h"
 #include "SupportMgr.h"
 #include "TaxiPathGraph.h"
 #include "TransportMgr.h"
@@ -437,6 +438,7 @@ void World::LoadConfigSettings(bool reload)
             return;
         }
         sLog->LoadFromConfig();
+        sMetric->LoadFromConfigs();
     }
 
     m_defaultDbcLocale = LocaleConstant(sConfigMgr->GetIntDefault("DBC.Locale", 0));
@@ -2128,6 +2130,8 @@ void World::SetInitialWorldSettings()
 
     TC_LOG_INFO("server.worldserver", "World initialized in %u minutes %u seconds", (startupDuration / 60000), ((startupDuration % 60000) / 1000));
 
+    TC_METRIC_EVENT("events", "World initialized", "World initialized in " + std::to_string(startupDuration / 60000) + " minutes " + std::to_string((startupDuration % 60000) / 1000) + " seconds");
+
     if (uint32 realmId = sConfigMgr->GetIntDefault("RealmID", 0)) // 0 reserved for auth
         sLog->SetRealmId(realmId);
 }
@@ -2430,6 +2434,10 @@ void World::Update(uint32 diff)
     ProcessCliCommands();
 
     sScriptMgr->OnWorldUpdate(diff);
+
+    // Stats logger update
+    sMetric->Update();
+    TC_METRIC_VALUE("update_time_diff", diff);
 }
 
 void World::ForceGameEventUpdate()