Dont u think its time we switch over to a custom site?
Wordpress should be able to easily handle this kind of volume.
So it's a DD issue and not a DDF issue? Maybe we can change how the DD search works (by using a wordpress plugin or something).
By we I mean you
So I was on the right track, but it wasn't a search issue. It was an issue with certain proxies and bots not respecting <link rel="archive" /> and actually loading the URL.
Those pages that were linked and getting hit, had intense database queries to calculate pagination. And to further complicate hunting down the issue, it didn't always happen. It only happened once that query for the pagination was no longer in the query cache.
I am pretty sure that this was the issue and has been fixed. But I will continue reviewing the logs to be sure.