mysql server gone away while loading drupal site in the shared environment i am getting serious error in the production server when i deploy for the first time. Please find the below PDO exception which i am getting.

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away in variable_set() (line 977 of /var/www/htdocs/includes/bootstrap.inc).


I am not allowed to increase allowed packet size and wait timeout in the mysql end, because multiple sites are running on the DB and such a way we are not allowed to change php.ini also.

Is there any other solution for this problem I am facing this issue with the client for past one week not it has been very critical for me.

Could anyone please help me out to get ride of this issue? Thanke in advance.
Increase max allowed packet size is the only proper way of doing this. 
If your host doesn't allow you to change values in your multi-site environment simply change the host because you could experience a lot more problems overtime if you're not allowed to change anything!
A quickfix solution could be to limit the number of activated modules and by this limit the number of queries executed on page loads.