On Wed, Sep 24, 2008 at 03:39:16AM -0700, BUI18 wrote: > I have squid box with tons of disk for the cache_dir > (hundreds of GB). I use wget to perform some pre-fetching of large > video files. I've set the min and max age to 5 days and 7 days (in > minutes). And although I have plenty of disk space available, I still > receive TCP_REFRESH_MISS for files that had been pre-fetched and later > accessed the same day. Does anyone know why Squid would consider it as > STALE? I thought that by setting the min value for refresh_pattern for > the video file would guarantee freshness. Not only does the cache > consider it STALE, it then goes and pre-fetches a new copy even though > I know that the video file has not changed. Any help would be greatly > appreciated. Thanks. The fact that it's doing TCP_REFRESH_xxx means squid does have a cached copy which it considers potentially stale. So it's sending an If-Modified-Since request to the origin server. The origin is then either saying "yes, it's been modified since you retrieved it -- here's a new one"; or it has no idea how to handle IMS and is sending the whole object regardless. What Expires: header is the server sending? You can use the -S switch with wget to show the server response headers when you're doing your pre-fetch. If they look fine, maybe keep a copy of them and compare later in the day when squid decides it needs a new one. I assume you're setting the min and max age via refresh_pattern lines? Remember that these are only used in the absence of an Expires header.
