I am fairly new to SharePoint, but we have 1 department site (we have 40 or so total) that keeps going down every 3-4 days it seems (screen just says "Working on it...."). They have a LOT of workflows(we use Nintex) on the site (30-40) and roughly 15-20 that run daily. We bring the site back up by resetting iis on the 2 SharePoint servers. This isn't ideal obviously, so we are trying to find the root cause and the logs don't really show anything.
I noticed in IIS App Pools that the Workflow Management pool has a idle-timeout of 20 minutes and a recycle time of every 29 hours instead of daily at 3:00 or so. Should these settings be changed to idle-timeout of 0 and recycle at 3:00am daily? Could this be causing the site to hang? All of our other pools have a 0 for idle-timeout and sometime early in the morning for recycle times.