dump-190.2 && dump-190.3: It looks like one request is for "gzip, deflate" and the other is not. The cache attempts to select an available alternative before re-issuing a request for a new alternative. The cache had a filled request for something that was not compressed, but the incoming request was for compressed data. At that point the cache rejects the alternate in storage and gets a fresh alternate from the origin server. It never checks the bytes in the result, so the fact that they are identical is lost.
dump-190.4: This is the same thing, except for content-type. The request is for text/plain or text/html, but the result is image/jpeg. When the cache asks "do I have an alternate that serves this new request" they will likely all fail as the alternates don't actually fulfill the request. In fact, I'd wager that while these are "cached" they are never served from the cache and each new requests bumps the oldest alternate off the list. The browser really should be requesting image/* or */* not text/*. On Mon, Dec 19, 2011 at 10:40 PM, ming....@gmail.com <ming....@gmail.com> wrote: > hi: > > When checking the request to Origin Server, we find that some of the > URL will show up multiple times in our log, and we dump the cache info: > > http://people.apache.org/~zym/dump-190.2.html > dumps a static jpg file, with 2 alternates > > http://people.apache.org/~zym/dump-190.3.html > dumps a static jpg file, with 2 alternates > > http://people.apache.org/~zym/dump-190.4.html > dumps a static jpg file, suffix as .jpg#, with 10 alternates > > my max alternates is set to 10. > > -- > zym, Zhao Yongming. > aka: yonghao @ taobao.com
