Pt-online-schema-change - Exiting due to errors while restoring triggers: DBD::mysql::db do failed: Lock wait timeout exceeded; try restarting transaction

[bob]

Dunno if it’s related, but restoring triggers is an issue for me too, even when ptosc completes:
See:

Triggers dropped after pt-osc usage

Good day,I’m facing strange issue, not for a first time. Sometimes it appears, sometimes it does not. I’m expecting it’s related to “drop_swap” method. Table stats_table2 is having 3 triggers. after running, all looks mint: At this moment table stats_table2 is not having 3 triggers. I’m always dumping triggers before running pt-osc - and in case of loosing triggers I’m importing them back again.Anyone faced similar behaviour, am I missing something in parameters? Any advice is highly apprec…

https://jira.percona.com/browse/PT-1919

I could only avoid the issue by ensuring the FK mode rebuild_constraint and avoiding the drop_swap.
Maybe that can help you.