I am running an Nginx reverse proxy on port 80, with Apache behind on port 81. I do not have nginx set up to serve boost cache files, only static assets.

If I hit port 80 from my browser, or curl on the box itself, it generates a cached file. However the crawler fails to generate a file, despite Apache access log suggesting the crawler is regularly hitting pages (the site is not public, access is only allowed for IP exceptions).

I have setup the cron to hit either Nginx or Apache directly, neither seems to make much difference, both show hits from to cron.php, /boost-crawler and various pages that must be originating from the crawler, but at no point are cache files generated.

After a couple of hours /boost-crawler is still being hit, but no crawling is happening at all now.

I am using Debug 9 but nothing in the dblog seems to point to any error, its simply full of the following messages:

boost	2012-07-17 10:32	Crawler - Thread 2 of 2 Done.	Anonymous	
boost	2012-07-17 10:32	Crawler - Thread 1 of 2 started	Anonymous	
cron	2012-07-17 10:32	Cron run completed.	Anonymous	
boost	2012-07-17 10:32	Crawler Sleep for 15 seconds	Anonymous	
boost	2012-07-17 10:32	Crawler Start ...	Anonymous	
boost	2012-07-17 10:32	Expired stale files from static page cache.	Anonymous	
boost	2012-07-17 10:32	Debug: boost_cache_expire_all_db() Following ...

According to the various buttons on the Boost Settings page there are:

- Boost cached data: 0 pages
- Boost expired data: 0 pages
- Database records: 0
- Files: 0