Core/DBLayer:

- Rewrite KeepAlive method for DatabaseWorkerPool. Use mysql_ping instead of explicit select queries, and also schedule KeepAlives for asynchronous threads.
NOTE: While the function is implemented and previous keepalive calls were transformed, it´s possible the keepalive call will need to be placed in several other locations in the code. Please leave feedback on whether or not this fixes your timeout issues.

Update issue #4062

--HG--
branch : trunk

src/server/shared/Database/MySQLConnection.h

@@ -50,6 +50,7 @@ class MySQLConnection
         void CommitTransaction();
 
         operator bool () const { return m_Mysql != NULL; }
+        void Ping() { mysql_ping(m_Mysql); }
 
     protected:
         MYSQL* GetHandle()  { return m_Mysql; }