> -----Original Message----- > From: Eric Covener > Sent: Montag, 7. Juli 2014 00:16 > To: Apache HTTP Server Development List > Subject: Re: svn commit: r1597706 - /httpd/httpd/branches/2.2.x/STATUS > > > + * mod_cache, mod_disk_cache: Try to use the key of a possible open > but > > + stale cache entry if there is one. This fixes problem when two > different > > + cache locks have been created for single stale cache entry leading > to two > > + requests sent to backend. > > + Remove useless apr_file_remove() before renaming the cache entry > in > > + mod_disk_cache. This fixes small time-frame during which stale > cache > > + entry can be seen as not-cached. > > + PR 50317 > > + 2.2.x patch: http://people.apache.org/~jkaluza/patches/httpd- > 2.2.x-thundering-herd.patch > > + > > When/why does the key differ? > > Why is it not needed/present in 2.4/trunk?
The cache_try_lock API changed between 2.2.x and 2.4.x/trunk. This is fixed in trunk (r1597533) but a backport to 2.4.x is missing. The keys can differ in case of Vary headers for the stale entry. Regards Rüdiger
