Slow page redirect when executing captive_portals_upkeep

[marino-mrc]

Hi, I'm using captive portals manager with apache and passenger. With a relatively high number of users (around 1000 unique logins per day), the redirect is slow. I discovered that the problem happens when captive_portals_upkeep is executed by backgroundrb. Why this happens? and how can I fix the issue? How much it depends from the web server? Should I try to use puma instead of passenger? Thank you