TCP_REFRESH_HIT / 304

After further investigations i found in "store.log" that in some conditions
the object is being deleted
from the cache right after the TCP_REFRESH_HIT / 304 prolly because of that
errononous (or not ?)
call of the store function ( SWAPOUT / RELEASE ) .

It means that in some conditions an object is deleted from the cache right
after it is being recalled
by a client and being said Not Modified by the remote server. If true it's
a major bug that dramatically
reduces the TCP_XXX_HIT ratio....

Here is an example :

(TCP_REFRESH_HIT = TRH)

Example where it doesn't happen (the file is not deleted after a TRH/304) :
----------------------------------------------------------------------------
----------------------

-> access.log
882392339.957 1589 194.250.215.11 TCP_MISS/200 2289 GET
http://www.n64bolt.com/core.jpg - DIRECT/www.n64bolt.com image/jpeg
-> store.log
882392339.867 SWAPOUT 200 882392460 878397770 -2 image/jpeg
2048/2048 GET http://www.n64bolt.com/core.jpg

-> access.log
883189135.063 920 194.250.215.11 TCP_REFRESH_HIT/304 2289 GET
http://www.n64bolt.com/core.jpg - DIRECT/www.n64bolt.com -
-> store.log
883189135.023 SWAPOUT 304 883189228 -2 -2 unknown 0/0 GET
http://www.n64bolt.com/core.jpg
883189135.023 RELEASE 304 883189228 -2 -2 unknown 0/0 GET
http://www.n64bolt.com/core.jpg

Example where it happens (the file is deleted after a TRH/304) :
----------------------------------------------------------------------------
--------

-> access.log
882664622.575 48707 194.250.215.10 TCP_MISS/200 18111 GET
http://www.yaesu.com/leader.gif - DIRECT/www.yaesu.com image/gif
-> store.log
882664622.595 SWAPOUT 200 882664728 852608784 -2 image/gif
17927/17927 GET http://www.yaesu.com/leader.gif

-> access.log
882941827.705 5860 194.250.215.10 TCP_REFRESH_HIT/304 18111 GET
http://www.yaesu.com/leader.gif - DIRECT/www.yaesu.com image/gif
-> store.log
882941827.475 SWAPOUT 304 882941968 852608784 -2 image/gif 17927/0
GET http://www.yaesu.com/leader.gif
882941827.475 RELEASE 304 882941968 852608784 -2 image/gif 17927/0
GET http://www.yaesu.com/leader.gif
882941827.705 RELEASE 304 882941968 852608784 -2 image/gif
17927/17931 GET http://www.yaesu.com/leader.gif

I found a _lot_ of files deleted after a (TRH/304) in the same way.

I dunno if it can help but in the case of the file is deleted (after a
TRH/304) the number "X/Y" in store.log is always Y=X+4 .
Received on Fri Dec 26 1997 - 20:21:45 MST