Re: Microsoft Server, squid, Microsoft Client

From: Marc Haber <Marc.Haber-lists@dont-contact.us>
Date: Thu, 16 Jul 1998 07:51:37 GMT

On Tue, 14 Jul 1998 16:29:59 -0400 (EDT), you wrote:
>> (2) Microsoft has started to use these funky "Active Server Pages".
>> Obviously, squid doesn't cache the page and retrieves it again every
>> time. In the case of the Knowledge Base Query page, this is 40 KB
>> each that can take quite some time on a saturated transatlantic
>> link. Can I tweak squid into caching Active Server Pages?
>
>Just adjust your squid.conf stoplists appropriately. Not sure that
>it's a good idea, though. The ASPs are dynamic pages, and if you
>cache them you can wind up with incorrect display on the client's
>browser.

I see. So the pattern "?" in the stoplist stops all URLs with
"?" from being cached. As support.microsoft.com currently ex-
pands to http://support.microsoft.com/support/c.asp?FR=0,
this page is not cached, right?

But I understand that squid sends an if-modified-since to the
server and reloads the page if it has changed. So it wouldn't
hurt to have such pages cached since I would get a new page
as soon it is available.

>> (3) I have found that squid releases pages from the cache. I don't
>> want this to happen since I still have a couple of GB free on my
>> cache partition. Why doesn't it keep the pages and issues an
>> if-modified-since when a new request comes in weeks later? This
>> surely can't be a disk memory issue.
>
>What makes you say that pages are being released from the cache?
>Which log entries are you seeing? From what I can tell, Squid should
>essentially fill up the cache until the high-water mark is reached
>with pages that have not been modified, and check if-modified-since if
>they are either older than the "max" field in refresh_pattern or have
>expired in accordance with the "Expires:" header.

|palandt:/cache/var/squid # tail -n 10 store.log | grep RELEASE
|900502997.297 RELEASE 304 900502956 -2 -2 unknown 0/0 GET http://support.microsoft.com/library/images/support/endcap.gif
|900502997.583 RELEASE 304 900502956 -2 -2 unknown 0/0 GET http://support.microsoft.com/library/images/support/ieaddchannel.gif
|900502997.997 RELEASE 304 900502949 -2 -2 unknown 0/0 GET http://support.microsoft.com/library/images/support/ie4get_animated.gif
|900502998.969 RELEASE 304 900502950 -2 -2 unknown 0/0 GET http://support.microsoft.com/library/images/support/one.gif
|900503000.437 RELEASE 304 900502952 -2 -2 unknown 0/0 GET http://support.microsoft.com/library/images/support/two.gif
|900503000.659 RELEASE 200 900502899 -2 900502899 text/html 45092/45092 GET http://support.microsoft.com/support/c.asp
|900503009.560 RELEASE 304 900502967 -2 -2 unknown 0/0 GET http://support.microsoft.com/library/images/support/three.gif
|palandt:/cache/var/squid # grep ../squid/etc/#

My squid.conf says "refresh_pattern . 30 20% 4320". Shouldn't that be
.* as a regexp?

This is my cachemgr output:
|info: www:8080
|dated Wed Jul 15 13:58:31 1998
|
|Squid Object Cache: Version 1.1.20
|Start Time: Sat, 11 Jul 1998 20:16:29 GMT
|Current Time: Wed, 15 Jul 1998 11:58:31 GMT
|Connection information for squid:
| Number of TCP connections: 467
| Number of UDP connections: 0
| Connections per hour: 5.3
| Select loop called: 371374 times, 850.146 ms avg
|Cache information for squid:
| Storage Swap size: 135 MB
| Storage Mem size: 880 KB
| Storage LRU Expiration Age: 365.00 days
| Requests given to unlinkd: 0
| Unused fileno stack count: 0
|Resource usage for squid:
| CPU Time: 21 seconds (11 user 10 sys)
| CPU Usage: 0%
| Maximum Resident Size: 0 KB
| Page faults with physical i/o: 1009
|Memory usage for squid via mallinfo():
| Total space in arena: 4194 KB
| Ordinary blocks: 4098 KB 1695 blks
| Small blocks: 0 KB 0 blks
| Holding blocks: 0 KB 0 blks
| Free Small blocks: 0 KB
| Free Ordinary blocks: 96 KB
| Total in use: 4098 KB 98%
| Total free: 96 KB 2%
|File descriptor usage for squid:
| Maximum number of file descriptors: 256
| Largest file desc currently in use: 17
| Number of file desc currently in use: 18
| Available number of file descriptors: 238
| Reserved number of file descriptors: 64
|Internal Data Structures:
| 15308 StoreEntries
| 270 StoreEntries with MemObjects
| 270 StoreEntries with MemObject Data
| 269 Hot Object Cache Items
|Accounted Memory Usage:
| StoreEntry 15308 x 52 bytes = 777 KB
| URL strings = 738 KB
| IPCacheEntry 1 x 36 bytes = 0 KB
| FQDNCacheEntry 0 x 56 bytes = 0 KB
| Hash link 269 x 12 bytes = 3 KB
| Pool MemObject structures 270 x 100 bytes = 26 KB ( 0 free)
| Pool for Request structur 12 x 4408 bytes = 51 KB ( 47 free)
| Pool for in-memory object 399 x 4096 bytes = 1596 KB ( 52 free)
| Pool for disk I/O 5 x 8192 bytes = 40 KB ( 40 free)
| NetDB Address Entries 0 x 76 bytes = 0 KB
| NetDB Host Entries 0 x 8 bytes = 0 KB
| NetDB Peer Entries 0 x 24 bytes = 0 KB
| ClientDB Entries 1 x 292 bytes = 0 KB
| Miscellaneous = 391 KB
| Total Accounted = 3624 KB
|
|--------------------------------------------------------------------------------
|
|Generated Wed, 15 Jul 1998 11:58:31 GMT, by cachemgr.cgi/1.1.20@palandt.ka.mydomain.de

This is how my disk utilization looks like

|palandt:/cache # du -s -k .
|188544 .
|palandt:/cache # df
|Filesystem 1024-blocks Used Available Capacity Mounted on
|/dev/sda6 893324 660746 186426 78% /
|/dev/sda9 201263 3416 187454 2% /tmp
|/dev/sda2 15336 46 14459 0% /boot
|/dev/sda8 2689869 188559 2362227 7% /cache
|palandt:/cache #

What am I missing?

Greetings
Marc

-- 
-------------------------------------- !! No courtesy copies, please !! -----
Marc Haber          |   " Questions are the         | Mailadresse im Header
Karlsruhe, Germany  |     Beginning of Wisdom "     | Fon: *49 721 966 32 15
Nordisch by Nature  | Lt. Worf, TNG "Rightful Heir" | Fax: *49 721 966 31 29
Received on Thu Jul 16 1998 - 00:54:20 MDT

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