Yeah - looks like it's emulating a lock so only one page can be rendered at a time (plus the overhead for database IO to maintain the lock). Is this really the best way to go about this?
Unless I'm missing something important, it's locking so the same page can only be rendering once at a time; if another request that would cause a rebuild comes in while a previous rebuild is still in progress, it gets bounced.
Yes, you are correct. We're trying to limit the system to one rendering per page at a time.