Hi,
I had this kind of errors every time I clear the cache, or install/uninstall modules, or make changes on views...etc. After a few seconds a white screen appears with this kind of errors:
Additional uncaught exception thrown while handling exception.
Original
PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT expire, value FROM {semaphore} WHERE name = :name; Array ( [:name] => theme_registry:runtime:seven:cache ) in lock_may_be_available() (line 167 of /var/www/clients/client2/web19/web/includes/lock.inc).
Additional
PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT expire, value FROM {semaphore} WHERE name = :name; Array ( [:name] => rules_get_cacherules_event_whitelist ) in lock_may_be_available() (line 167 of /var/www/clients/client2/web19/web/includes/lock.inc).
________________________________________
Uncaught exception thrown in shutdown function.
PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: DELETE FROM {semaphore} WHERE (value = :db_condition_placeholder_0) ; Array ( [:db_condition_placeholder_0] => 1917749777570f6780cbc894.71899901 ) in lock_release_all() (line 269 of /var/www/clients/client2/web19/web/includes/lock.inc).
...
I increased the max_allowed_packet to a very high value (2048M) but nothing changed.
Every time these errors appear, I have to restart the server or wait for a few hours to make the website working again.
Could you help to solve this issue please?
Thank you