I am using CodeIgniter's database-backed sessions with persistent connections OFF.
Every once in awhile I have a lot of MySQL of connections pile up because of a lot of requests on the same session. I understand the reason locking is needed (Prevent concurrent writes), but the other downside is a lot of stress is put on the database server causing it to run slow until the connections are cleared out.
I tried Redis session driver but that performed poorly and its locking didn't seem to work as well as MySQL. (Performed poorly)
I use amazon web services RDS and EC2.
Would turning on persistent connections help this issue?