Redmine

I'm fighting with MySQL in one of our Redmine projects. We have a quite large environment (391 projects with 750 active Redmine users ) and it's working really well for years. There is one project which had very complex requirements and right now it's the only project which is leading to these failures so far. This project has about 40 custom ticket fields and some tickets have about 20 subtickets.

Please find attached our actual envrionment settings.

I'm looking forward for any pointers or help which could lead to solution. We already tried to tune MySQL with mysqltuner and tuningprimer. I also tried to set innodb_table_locks=0 but none of our changes seems to have any effect regarding the locks. I have quite basic MySQL knowledge I think this is something more advanced.

Best regards,

Tobias