Hundreds of unserialize requests I have a large Drupal 7 website on my hands that is very large and has loads of modules (over 200).
I am already seeing poor performance symptoms in the FPM logs with max_children limits reached on the Acquia server.
I installed a profiler (blackfire) and the main issue (on every page) is an absurd amount of calls to unserialize (over 300) coming from DrupalDatabaseCacheprepareItem (autenticated).
This happens even on a basic page.
I am having a tough time coming up with a solid strategy to pinpoint the bottleneck and which module(s) are the culprit.

Anyone can help me with this?
I ended up using the variable debug module, which was incredibly useful in helping me find out the expensive variables I had.