i have received message from the server team
We request you to please change the database engine to MyISAM or Aria if your software does not necessarily need InnoDB. Please note that Innodb is known not to be the fastest engine.
Your host obviously knows nothing about Mysql. While Inndob is a bit slower under certain circumstances, Xenforo itself is blazingly fast and puts much less load on the database than other forum software.
Time for a new host.