Q: squid1.1a12: Caching and immediately releasing objects?

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Hi squitters!

I have a question on squid 1.1 alpha 12. Under certain circumstances it seems
he immediately releases entries which have been cached just some seconds ago.
Those entries are reported (via cachemgr and cache/log) to be present in the
disk-cache, but requesting them result in a TCP_MISS message.

An example (store.log):
...
841221887.256 SWAPOUT 200 860717 [ 1W] 4681/4681 http://www.hp.com/
841221952.758 SWAPOUT 200 583950 [ 6D] 3510/3510 http://www.hp.com/germany/index.html
841222220.308 SWAPOUT 200 17069 [ 4h] 8213/8213 http://www-dmo.external.hp.com/peripherals/main.html
841222288.992 SWAPOUT 200 604800 [ 1W] 0/915 http://www.rp-online.de/Wetter/Isobaren-Karte.html
841222293.188 RELEASE 200 604795 [ 6D] 0/915 http://www.rp-online.de/Wetter/Isobaren-Karte.html
841222293.800 SWAPOUT 200 604800 [ 1W] 0/915 http://www.rp-online.de/Wetter/Isobaren-Karte.html
841222297.382 SWAPIN 200 333060 [ 3D] 0/1096 http://www.rp-online.de/Grafiken/Butt-News.gif
841222298.051 RELEASE 200 604795 [ 6D] 0/915 http://www.rp-online.de/Wetter/Isobaren-Karte.html
841222298.051 RELEASE 200 333059 [ 3D] 0/1096 http://www.rp-online.de/Grafiken/Butt-News.gif
841222298.051 RELEASE 200 583604 [ 6D] 3510/3510 http://www.hp.com/germany/index.html

Further requests (e.g for http://www.hp.com/germany/index.html) never result
in a HIT, instead the document must always be fetched again.

This error(?) did not occur under squid 1.1a11, so perhaps it's got something
to do with the new storeGetMemSpace routine.

Here's a sample of the cache.log:
...
[28/Aug/1996:11:20:45 +0200] store.c:2474: storeEntryValidLength: Checking 'http://www.hp.com/'
[28/Aug/1996:11:20:45 +0200] store.c:2475: storeEntryValidLength: object_len = 4926
[28/Aug/1996:11:20:45 +0200] store.c:2476: storeEntryValidLength: hdr_sz = 245
[28/Aug/1996:11:20:45 +0200] store.c:2477: storeEntryValidLength: content_length = 4681
[28/Aug/1996:11:20:45 +0200] store.c:1359: storeSwapOutStart: Begin SwapOut <URL:http://www.hp.com/> to FD 20 FILE /WWW/WWW/cache/03/DD/00000DD3.
[28/Aug/1996:11:20:45 +0200] store.c:567: storeUnlockObject: key 'http://www.hp.com/' count=1
[28/Aug/1996:11:20:46 +0200] store.c:567: storeUnlockObject: key 'http://www.hp.com/' count=0
[28/Aug/1996:11:20:46 +0200] store.c:1260: storeSwapOutHandle: 'http://www.hp.com/'
[28/Aug/1996:11:20:46 +0200] store.c:1305: storeSwapOutHandle: SwapOut complete: <URL:http://www.hp.com/> to /WWW/WWW/cache/03/DD/00000DD3.
[28/Aug/1996:11:20:46 +0200] store.c:2730: Removed 0 expired objects
...
[28/Aug/1996:11:20:46 +0200] store.c:1902: storeGetMemSpace: Starting...
...
[28/Aug/1996:11:20:46 +0200] store.c:1918: storeGetMemSpace: Adding 'http://www.jobnet.de/gif/jn.gif'
[28/Aug/1996:11:20:46 +0200] store.c:1918: storeGetMemSpace: Adding 'http://www.hp.com/'
[28/Aug/1996:11:20:46 +0200] store.c:1918: storeGetMemSpace: Adding 'http://www.jobnet.de/gif/ct.gif'
[28/Aug/1996:11:20:46 +0200] store.c:1918: storeGetMemSpace: Adding 'http://www.jobnet.de/gif/loop.gif'
[28/Aug/1996:11:20:46 +0200] store.c:1918: storeGetMemSpace: Adding 'http://www.hp.de/'
[28/Aug/1996:11:20:46 +0200] store.c:1918: storeGetMemSpace: Adding 'http://www.cle.creaf.com/creative/drivers/sb16awe/awedw3up.exe'
[28/Aug/1996:11:20:46 +0200] store.c:1918: storeGetMemSpace: Adding 'http://home.netscape.com/'
...
[28/Aug/1996:11:20:46 +0200] store.c:1928: storeGetMemSpace: Sorting LRU_list: 32 items
[28/Aug/1996:11:20:46 +0200] store.c:2188: storeRelease: Releasing: '506/GET/http://www.hp.de/'
[28/Aug/1996:11:20:46 +0200] store.c:637: storeGeneratePublicKey: type=4 http://www.hp.de/
[28/Aug/1996:11:20:46 +0200] store.c:2233: storeRelease: Release object key: 506/GET/http://www.hp.de/
[28/Aug/1996:11:20:46 +0200] store.c:305: destroy_StoreEntry: destroying 62e670
...
[28/Aug/1996:11:20:46 +0200] store.c:335: destroy_MemObjectData: destroying 62b9b8
[28/Aug/1996:11:20:46 +0200] store.c:2188: storeRelease: Releasing: 'http://www.hp.com/'
[28/Aug/1996:11:20:46 +0200] store.c:637: storeGeneratePublicKey: type=4 http://www.hp.com/
[28/Aug/1996:11:20:46 +0200] store.c:2233: storeRelease: Release object key: http://www.hp.com/
[28/Aug/1996:11:20:46 +0200] store.c:305: destroy_StoreEntry: destroying 62e778
[28/Aug/1996:11:20:46 +0200] store.c:283: destroy_MemObject: destroying 636558
...
[28/Aug/1996:11:20:46 +0200] store.c:1946: storeGetMemSpace: After freeing size: 3683591 bytes
[28/Aug/1996:11:20:46 +0200] store.c:1947: storeGetMemSpace: Released: 16 items
[28/Aug/1996:11:20:46 +0200] store.c:1969: storeGetMemSpace: Done.

My understandig is that storeGetMemSpace just releases Objects which are
currently in core, but it seems it actually wipes them out of the disk cache,
since the cache-size didn't increase (when using squid 1.1a12). (cache_swap is
set to 1500, currently 170 MB are used)

Has anyone got any ideas, comments?

Thanks for any information!

MfG
MB
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Received on Thu Aug 29 1996 - 08:02:47 MDT