stover'tes', chto
na rabochih stanciyah propisany lokal'nye DNS servera.

<P>Esli na brandmauere ili proksi servere rabotaet DNS server (chto yavlyaetsya
horoshej ideej IMHO) pust' rabochie stancii ispol'zuyut ego.

<P>
<HR>
<H2>
<A NAME="5"></A>5 Opisanie raboty</H2>

<H3>
<A NAME="5.1"></A>5.1 Kak posmotret' sistemnuyu statistiku raboty Squid?</H3>
V sostav distributiva Squid vhodit CGI utilita <I>cachemgr.cgi</I> dlya
prosmotra statistiki squid cherez brauzer. Dlya bol'shej informacii obratites'
k razdelu, posvyashchennomu <I>cachemgr.cgi.</I>
<H3>
<A NAME="5.2"></A>5.2 CHto ya mogu uznat' iz log fajlov?</H3>
Fajly soderzhat razlichnuyu informaciyu o zagruzke i proizvoditel'nostie Squid.
V log pishutsya krome informacii o dostupe, eshche i sistemnye oshibki i informaciya
o potreblenii resursov, takih, naprimer, kak pamyat' ili diskovoe prostranstvo.
Nizhe opisan format log fajlov Squid:

<P><I>access.log</I>, obshchij format:
<PRE>ššš Host Ident - [D/M/Yr:H:M:S TZ] "Method URL" Status Size</PRE>
<I>access.log</I>, Squid 1.0 rodnoj format:
<PRE>ššš Time Elapsed Host Status/HTTP/Hier_Status Size Method URL</PRE>
<I>access.log</I>, Squid 1.1 rodnoj format:
<PRE>ššš Time Elapsed Host Status/HTTP Size Method URL Ident Hier_Status/Hier_Host</PRE>
<I>hierarchy.log</I>, tol'ko Squid 1.0:
<PRE>ššš [D/M/Yr:H:M:S TZ] URL Hier_Status Hier_Host</PRE>
Zdes' opisanie formata raznyh komponentov log:
<DL>
<DT>
<TT>Host</TT></DT>

<DD>
IP adresa zaprashivaemyh hostov (v versii v1.1, esli zadano mozhet byt' FQDN).</DD>

<DT>
<TT>Ident</TT></DT>

<DD>
Obychno '-'. V versii 1.1 otvet Ident (RFC 931), esli zadano.</DD>

<DT>
<TT>Method</TT></DT>

<DD>
GET, HEAD, POST dlya TCP zaprosov ili ICP_QUERY dlya UDP zaprosov.</DD>

<DT>
<TT>URL</TT></DT>

<DD>
Zaprashivaemyj obฎekt.</DD>

<DT>
<TT>Status</TT></DT>

<DD>
Rezul'tat zaprosa (TCP_HIT dlya ranee keshiruemyh obฎektov, TCP_MISS esli
zaprashivaemyj obฎekt vzyat ne iz lokal'nogo kesha, UDP_HIT i UDP_MISS to
zhe dlya bratskih zaprosov).</DD>

<DT>
<TT>HTTP</TT></DT>

<DD>
Vozvrashchaemyj HTTP kod: 200 dlya udachnyh, 000 dlya UDP zaprosov, 403 dlya perenapravlenij,
500 dlya oshibok, i t.d.</DD>

<DT>
<TT>Size</TT></DT>

<DD>
Kolichestvo bajt peredannyh klientu.</DD>

<DT>
<TT>Hier_Status</TT></DT>

<DD>
Rezul'tat zaprosov k bratskim/roditel'skim kesham. Mozhet byt' PARENT_MISS,
SIBLING_HIT i t.d.</DD>

<DT>
<TT>Hier_Host</TT></DT>

<DD>
Host, s kotorogo vzyat obฎekt.</DD>

<DT>
<TT>Time</TT></DT>

<DD>
Vremya s Jan 1, 1970 v millisekundah.</DD>

<DT>
<TT>Elapsed</TT></DT>

<DD>
Zatrachennoe vremya v millisekundah.</DD>
</DL>

<H3>
<A NAME="5.3"></A>5.3 Kakie log fajly ya mogu udalyat'?</H3>
CHtoby sohranit' log fajly, luchshe poslat' processu <I>squid</I> signal USR1.
|to privedet k tomu, chto tekushchie log fajly budut zakryty i pereimenovany.
Posle etogo mozhno udalyat' starye log fajly. Naprimer,esli Vash fajl <I>squid.pid</I>
nahoditsya v<I>/usr/local/squid/logs/squid.pid</I> (kak zadano v <I>squid.conf</I>)
nado sdelat' sleduyushchee:

<P><TT>kill -USR1 `cat /usr/local/squid/logs/squid.pid`</TT>

<P><B><I>Primechanie:</I></B> Stroka <TT>logfile_rotate</TT> v <I>squid.conf</I>
delaet neobyazatel'nym ruchnoe udalenie staryh log fajlov. Prosto ustanovite
znachenie <TT>logfile_rotate</TT> v zhelaemuyu velichinu. Kak tol'ko znachenie
<TT>logfile_rotate</TT> budet dostignuto, staryj log budet udalen avtomaticheski.
Vystavite nuzhnoe znachenie <TT>logfile_rotate</TT> i propishite v crontab
posylku <I>squid</I> 'u signala <TT>SIGUSR1,</TT> naprimer v polnoch' kazhdogo
dnya:

<P><TT>0 0 * * * /bin/kill -USR1 `cat /usr/local/squid/logs/squid.pid`</TT>

<P>Edinstvennyj fajl, kotryj <B><I>nel'zya </I></B>udalyat' eto <TT>log,</TT>
kotoryj obychno nahoditsya v pervoj <TT>cache_dir</TT> direktorii. |tot fajl
soderzhiit dannye, neobhodimye dlya vosstanovleniya kesha prizapuske Squid.
<B><I>Udalenie etogo fajla privedet k potere kesha.</I></B>
<H3>
<A NAME="5.4"></A>5.4 Kak mne najti samyj bol'shoj obฎekt kesha?</H3>

<PRE>sort -r -n +4 -5 access.log | awk '{print $5, $7}' | head -25</PRE>

<H3>
<A NAME="5.5"></A>5.5 YA hochu perezapustit' Squid s chistym keshem</H3>
Pervyj sposob, dobavit' <TT>-z</TT> v komandnoj stroke.

<P>Drugoj, vozmozhno bolee prostoj, udalit' fajl <TT>log</TT> iz direktorii
<TT>cache_dir</TT>.š
<HR>
<H2>
<A NAME="6"></A>6 Kesh-menedzher</H2>
[Contributed by Jonathan Larmour &lt;JLarmour@origin-at.co.uk>]
<H3>
<A NAME="6.1"></A>6.1 CHto takoe kesh-menedzher?</H3>
Kesh-menedzher (<I>cachemgr.cgi</I>) eto CGI utilita dlya prosmotra statistiki
rabotayushchego processa <I>squid</I>. Kesh-menedzher eto prostoj sposob upravleniya
keshem i prosmotra statistiki bez zahoda na server.
<H3>
<A NAME="6.2"></A>6.2 Kak ego ustanovit'?</H3>
Prezhde vsego eto zavisit ot web servera, kotoryj Vy ispol'zuete. Nizhe Vy
najdete instrukcii po nastrojke CERN i Apache serverov dlya pol'zovaniya
<I>cachemgr.cgi</I>.

<P>Posle togo kak Vy izmenili konfiguracionnye fajly servera, nuzhno ili
perezapustit' web server, libo poslat' emu <TT>SIGHUP</TT>, chtoby on pereschital
fajly nastrojki.

<P>Kogda Vy zakonchite konfigurirovat' web server, to smozhete podklyuchit'sya
brauzerom k kesh-menedzheru po URL:

<P><TT>http://www.example.com/Squid/cgi-bin/cachemgr.cgi</TT>
<H3>
<A NAME="6.3"></A>6.3 Nastrojka CERN httpd 3.0 dlya raboty s kesh-menedzherom</H3>
Vo-pervyh, sleduet ubedit'sya, chto tol'ko ukazannye rabochie stancii imeyut
dostup k kesh-menedzheru. Ih nado zadat' v CERN <I>httpd.conf</I>, a ne v
<I>squid.conf</I>.
<PRE>ššššššš Protection MGR-PROT {
šššššššššššššššš Maskššš @(workstation.example.com)
ššššššš }</PRE>
Mozhno zadavat' shablonami, IP adresami, v tom chisle i cherez zapyatuyu. Vozmozhny
i drugie sposoby zashchity. Obratites' k dokumentacii po serveru.

<P>Takzhe sleduet dobavit':
<PRE>ššššššš Protectšššššššš /Squid/*ššššššš MGR-PROT
ššššššš Execššššššššššš /Squid/cgi-bin/*.cgiššš /usr/local/squid/bin/*.cgi</PRE>
chtoby otmetit' dlya <TT>MGR-PROT</TT>, chto skript vypolnyaemyj.
<H3>
<A NAME="6.4"></A>6.4 Nastrojka Apache dlya raboty s kesh-menedzherom</H3>
Snachala ubedites', chto direktoriya cgi-bin propisana v <TT>ScriptAlias</TT>
v fajle <I>srm.conf</I> Vashego Apache, kak-to tak:
<PRE>ScriptAlias /Squid/cgi-bin/ /usr/local/squid/cgi-bin/</PRE>
<B>Ne sovetuem</B> delat' <TT>ScriptAlias</TT> na vsyu direktoriyu <I>/usr/local/squid/bin</I>
gde lezhat binarniki Squid.

<P>Zatem, nado zadat' rabochie stancii imeyushchie dostup k kesh-menedzheru. |to
zadaetsya v fajle <I>access.conf</I> Apache, a ne v <I>squid.conf</I>. V
konce <I>access.conf</I>, vstav'te:
<PRE>ššššššš &lt;Location /Squid/cgi-bin/cachemgr.cgi>
ššššššš order deny,allow
ššššššš deny from all
ššššššš allow from workstation.example.com
ššššššš &lt;/Location></PRE>
Mozhno vpisat' neskol'ko strok, mozhno dobavit' domeny ili seti.

<P>Takzhe, <I>cachemgr.cgi</I> mozhet byt' zashchishchen parolem. Nado dobavit'
sleduyushchie stroki v <I>access.conf</I>:
<PRE>ššššššš &lt;Location /Squid/cgi-bin/cachemgr.cgi>
ššššššš AuthUserFile /path/to/password/file
ššššššš AuthGroupFile /dev/null
ššššššš AuthName User/Password Required
ššššššš AuthType Basic
ššššššš &lt;Limit GET>
ššššššš require user cachemanager
ššššššš &lt;/Location></PRE>
V dokumentacii Apache Vy najdete informaciyu ob ispol'zovanii <I>htpasswd</I>
dlya zadaniya parolya.
<H3>
<A NAME="6.5"></A>6.5 Zadanie ACL (spiska pol'zovatelej) dlya kesh-menedzhera
v <I>squid.conf</I></H3>
Po umolchaniyu dostup k kesh-menedzheru zadan v <I>squid.conf</I> tak:
<PRE>ššššššš acl manager proto cache_object
ššššššš acl localhost src 127.0.0.1/255.255.255.255
ššššššš acl all src 0.0.0.0/0.0.0.0</PRE>
So sleduyushchimi pravami:
<PRE>ššššššš http_access deny manager !localhost
ššššššš http_access allow all</PRE>
Pervaya zapis' v ACL nuzhna dlya kesh-menedzhera, tak kak on dlya oprosa squid
ispol'zuet special'nyj <TT>cache_object</TT> protokol. Mozhete sami poprobovat':

<P><TT>telnet mycache.example.com 3128</TT>
<BR><TT>GET cache_object://mycache.example.com/info HTTP/1.0</TT>

<P>Po umolchaniyu, esli zapros dlya <TT>cache_object</TT>, i zapros ne s lokal'noj
mashiny, to dostup budet zakryt, v protivnom sluchae - otkryt.

<P>Fakticheski, tak kak dostup razreshen tol'ko s lokal'noj mashiny, to v
pole <I>cachemgr.cgi</I> mozhno ukazat' v kachestve kesh hosta <TT>localhost</TT>.
My rekomenduem sleduyushchee:
<PRE>ššššššš acl manager proto cache_object
ššššššš acl localhost src 127.0.0.1/255.255.255.255
ššššššš acl example src 123.123.123.123/255.255.255.255
ššššššš acl all src 0.0.0.0/0.0.0.0</PRE>
Gde <TT>123.123.123.123</TT> eto IP adres Vashego web servera. Zatem izmenite
pravila tak:
<PRE>ššššššš http_access deny manager !localhost !example
ššššššš http_access allow all</PRE>
Po umolchaniyu podrazumevaetsya, chto web server nahoditsya na toj zhe mashine,
chto i <I>squid</I>. Uchtite, chto obrashchenie kesh-menedzhera k squid proishodit
cherez web server, a ne brauzer. Tak chto, esli Vash web server nahoditsya
gde-to v drugom meste, IP adres web servera, na kotorom ustanovlen <I>cachemgr.cgi</I>
dolzhen byt' ukazan vmesto <TT>example</TT> v vysheprivedennom primere.

<P>Ne zabyvajte kazhdyj raz posle izmeneniya <I>squid.conf </I>posylat' <TT>SIGHUP</TT>
<I>squid'u.</I>
<H3>
<A NAME="6.6"></A>6.6 Pochemu on sprashivaet u menya kakoj-to parol' i URL?</H3>
Esli Vy posmotrite v vypadayushchem spiske, to uvidite, chto parol' nuzhen tol'ko
dlya ostanovki kesha, a URL nuzhen dlya obnovleniya obฎekta (to est', povtornogo
polucheniya ego s ishodnogo servera). Dlya polucheniya informacii ot <I>cachemgr.cgi
</I>parol' ne trebuetsya.
<H3>
<A NAME="6.7"></A>6.7 YA hochu udalenno ostanovit' kesh. Kakoj parol'?</H3>
V <I>squid.conf </I>est' direktiva <TT>cachemgr_passwd</TT>.
<H3>
<A NAME="6.8"></A>6.8 Kak sdelat', chtoby v pole cache host po umolchaniyu
bylo imya <I>moego</I> kesha?</H3>
Najdite v fajle Makefile.in sleduyushchuyu stroku:
<PRE>ššššššš HOST_OPTššššššš = # -DCACHEMGR_HOSTNAME="getfullhostname()"</PRE>
Esli web server s <I>cachemgr.cgi </I>zapushchen na toj zhe mashine, chto i Squid
prosto uberite <TT>#</TT>. Esli zhe web server kakoj-to drugoj, to:
<PRE>ššššššš HOST_OPTššššššš = -DCACHEMGR_HOSTNAME=\"mycache.example.com\"</PRE>
Posle etih izmenenij sleduet perekompilirovat' i pereustanovit' cachemgr.cgi.
<H3>
<A NAME="6.9"></A>6.9 Kakaya raznica mezhdu TCP i UDP soedineniyami Squid?</H3>
Brauzery i keshi ispol'zuyut TCP soedineniya dlya polucheniya obฎektov s web
serverov ili keshej. UDP soedineniya ispol'zuyutsya kogda drugoj kesh ispol'zuet
Vash v kachestve bratskogo ili roditel'skogo na predmet nalichiya nuzhnogo obฎekta.
UDP soedineniya eto ICP zaprosy.
<H3>
<A NAME="6.10"></A>6.10 On govorit, chto srok hraneniya kesha istechet v 1970
godu!</H3>
Ne volnujtes'. Obychnoe (i v obshchem-to razumnoe) povedenie <I>squid</I> eto
perezapisyvat' obฎekty, srok hraneniya kotoryh istek.
<H3>
<A NAME="6.11"></A>6.11 CHto znachat zapisi meta-dannyh?</H3>

<DL>
<DT>
<TT>StoreEntry</TT></DT>

<DD>
Zapis' opisyvaet obฎekt kesha.</DD>

<DT>
<TT>IPCacheEntry</TT></DT>

<DD>
Zapis' v keshe DNS.</DD>

<DT>
<TT>Hash link</TT></DT>

<DD>
Zveno v strukture hesh-tablicy.</DD>

<DT>
<TT>URL strings</TT></DT>

<DD>
Sami stroki URL, ukazyvayushchie na nomer obฎekta v keshe, pozvolyayushchie obrashchat'sya
k <TT>StoreEntry</TT>.</DD>
</DL>
V osnovnom pohozhe na log fajl v direktorii cache:
<DL>
<DT>
<TT>PoolMemObject structures</TT></DT>

<DD>
Informaciya ob obฎektah nahodyashchihsya v pamyati, (naprimer, v processe peredachi).</DD>

<DT>
<TT>Pool for Request structures</TT></DT>

<DD>
Informaciya o kazhdom zaprose.</DD>

<DT>
<TT>Pool for in-memory object</TT></DT>

<DD>
Prostranstvo dlya prinyatyh obฎektov.</DD>
</DL>

<H3>
<A NAME="6.12"></A>6.12 Pool for in-memory object <B>ogromen</B> i ne stanovitsya
men'she! |to chto utechka pamyati?</H3>
Net. |tot pul tol'ko uvelichivaetsya. On raven samomu bol'shomu obฎektu kogda
libo keshiruemomu <I>squid</I> . Esli Vy ne hotite, chtoby on byl takogo
razmera, umen'shite znachenie <TT>cache_mem</TT> i razmer obฎektov dlya gopher,
http i ftp v <I>squid.conf</I>.
<H3>
<A NAME="6.13"></A>6.13 Znachenie polya "Total accounted" ne sovpadaet s
razmerom zanimaemym moim <I>squid</I>!</H3>
Esli eto znachenie blizko k upomyanotumu, ne volnujtes'. Esli <I>squid</I>
zanimaet namnogo bol'she, vozmozhno eto utechka pamyati, i vse chto mozhno delat'
eto zhdat' novyh patchej i vremya ot vremeni perezapuskat' <I>squid</I>.

<P>Esli <I>squid</I> zanimaet gorazdo men'she, chem v etom pole, bud'te ostorozhny!
CHto-to ne tak, sleduet perezapustit' <I>squid</I>.
<H3>
<A NAME="6.14"></A>6.14 V razdele utilization, chto est' <TT>Other</TT>?</H3>
<TT>Other</TT> eto kategoriya, v katoruyu popadayut obฎekty ne popavshie ni
v kakuyu druguyu.
<H3>
<A NAME="6.15"></A>6.15 V razdele utilization, pochemu kolonka <TT>Transfer
KB/sec</TT> vsegda nulevaya?</H3>
|ta kolonka soderzhit gruboe priblizhenie otnosheniya peredannyh dannyh k polnomu
vremeni raboty kesha. |ti dannye nenadezhnye i prakticheski bespoleznye.
<H3>
<A NAME="6.16"></A>6.16 V razdele utilization, chto znachit <TT>Object Count</TT>?</H3>
CHislo obฎektov dannogo tipa, nahodyashchihsya v dannyj moment v keshe.
<H3>
<A NAME="6.17"></A>6.17 V razdele utilization, chto znachit <TT>Max/Current/Min
KB</TT>?</H3>
|to otnositsya k uvelichivaemomu/tekushchemu/umen'shaemomu razmeru vseh obฎektov
etogo tipa.
<H3>
<A NAME="6.18"></A>6.18 O chem razdel <TT>I/O</TT>?</H3>
|to gistogrammy chisla bajt vzyatyh iz seti vyzovom <TT>read(2)</TT>. Dovol'no
polezny dlya opredeleniya maksimal'nogo razmera buferov.
<H3>
<A NAME="6.19"></A>6.19 CHto nahoditsya v razdele <TT>Objects</TT>?</H3>
<B><I>Preduprezhdenie:</I></B> v etom razdele Vash brauzer poluchit spisok
vseh URL kesha i statistiku o nih. On mozhet byt' ochen', ochen' bol'shim. <B><I>Inogda
on mozhet byt' bol'she, chem dostupnaya Vashemu klientu pamyat'!</I></B> Veroyatno
Vam eta informaciya nikogda ne ponadobitsya.
<H3>
<A NAME="6.20"></A>6.20 Dlya chego razdel <TT>VM Objects</TT>?</H3>
<TT>VM Objects</TT> eto obฎekty nahodyashchiesya v virtual'noj pamyati. |ti obฎekty
uzhe skacheny i nahodyatsya v pamyati dlya bystrogo dostupa k nim.
<H3>
<A NAME="6.21"></A>6.21 CHto znachit <TT>AVG RTT</TT>?</H3>
Average Round Trip Time. Pokazyvaet srednee vremya, proshedshee ot posylki
ICP ping do prihoda otveta.
<H3>
<A NAME="6.22"></A>6.22 V razdele IP cache , kakaya raznica mezhdu hit, negative
hit i miss?</H3>
HIT znachit, chto dokument najden v keshe. MISS, chto ne najden. Negative hit
oznachaet, chto on nahodilsya v keshe, no ne sushchestvuet.
<H3>
<A NAME="6.23"></A>6.23 CHto znachit soderzhimoe razdela IP cache?</H3>
Hostname eto imya, kotoroe sleduet preobrazovat'.

<P>Dlya kolonki <TT>Flags</TT>:
<DL COMPACT>
<DT>
<TT>C</TT></DT>

<DD>
Keshirovan.</DD>

<DT>
<TT>N</TT></DT>

<DD>
Ne keshirovan.</DD>

<DT>
<TT>P</TT></DT>

<DD>
Zapros otlozhen dlya posylki.</DD>

<DT>
<TT>D</TT></DT>

<DD>
Zapros poslan i ozhidaetsya otvet.</DD>

<DT>
<TT>L</TT></DT>

<DD>
Zapis' blokirovana, potomu chto vystupaet v roli roditelya ili brata.</DD>
</DL>
V kolonke <TT>TTL</TT> predstavleny "Time To Live" (to est', kak dolgo
zapis' v keshe dejstvitel'na). (Mozhet byt' otricatel'nym, esli srok hraneniya
dokumenta istek.)

<P>Kolonka <TT>N</TT> eto chislo IP adresov, kotorye imeet dannyj hostname.

<P>V konce stroki perechisleny ostal'nye IP adresa, otnosyashchiesya k etoj zapisi
v IP cache.
<H3>
<A NAME="6.24"></A>6.24 Kak analizirovat' ispol'zovanie pamyati iz dannyh
<I>cachemgr.cgi</I>?</H3>
Vzglyanite na stranicu <TT>Cache Information</TT> Vashego <I>cachemgr.cgi.</I>
Naprimer:
<PRE>ššššššš Memory usage for squid via mallinfo():
šššššššššššššš Total space in arena:šš 94687 KB
šššššššššššššš Ordinary blocks:ššššššš 32019 KB 210034 blks
šššššššššššššš Small blocks:šššššššššš 44364 KB 569500 blks
šššššššššššššš Holding blocks:šššššššššššš 0 KBšš 5695 blks
šššššššššššššš Free Small blocks:šššššš 6650 KB
šššššššššššššš Free Ordinary blocks:šš 11652 KB
šššššššššššššš Total in use:šššššššššš 76384 KB 81%
šššššššššššššš Total free:šššššššššššš 18302 KB 19%


ššššššš Meta Data:
ššššššš StoreEntryššššššššššššššš 246043 x 64 bytes =š 15377 KB
ššššššš IPCacheEntryššššššššššššš 971 xšš 88 bytesš =šššš 83 KB
ššššššš Hash linkšššššššššššššššš 2 xšš 24 bytesššš =ššššš 0 KB
ššššššš URL stringsšššššššššššššššššššššššššššššššš =š 11422 KB
ššššššš Pool MemObject structures 514 xš 144 bytesš =šššš 72 KB (ššš 70 free)
ššššššš Pool for Request structur 516 x 4380 bytesš =šš 2207 KB (š 2121 free)
ššššššš Pool for in-memory object 6200 x 4096 bytes =š 24800 KB ( 22888 free)
ššššššš Pool for disk I/Ošššššššš 242 x 8192 bytes =šš 1936 KB (š 1888 free)
ššššššš Miscellaneousššššššššššššššššššššššššššššš =šš 2600 KB
ššššššš total Accountedššššššššššššššššššššššššššš =š 58499 KB</PRE>
V pervoj stroke <TT>mallinfo()</TT> soobshchaet, chto ispol'zuetsyar 94M. |to
znachenie blizko k tomu, chto pokazyvaet <I>top</I> (97M).

<P>Iz etih 94M, 81% (76M) real'no ispol'zuetsya v etot moment. Ostal'noe
vysvobozhdeno, ili zarezervirovano <TT>malloc(3)</TT> i poka ne ispol'zuetsya.

<P>Iz 76M ispol'zuemyh, mozhno rasschityvat' na 58.5M (76%). Ostal'noe otvedeno
pod vyzovy <TT>malloc(3)</TT>.

<P>Spisok <TT>Meta Data</TT> soderzhit informaciyu o tom, kuda potrachena
dostupnaya pamyat'. 45% ushlo na <TT>StoreEntry</TT> i hranenie URL strok.
Drugie 42% potracheny na hranenie obฎektov v virtual'noj pamyati, poka oni
dostavlyayutsya klientam (<TT>Pool for in-memory object</TT>).

<P>Razmery pula zadayutsya v <I>squid.conf</I>. V versii 1.0, oni neskol'ko
tupovatye: tam hranitsya stek neispol'zovannyh stranic, vmesto togo chtoby
osvobozhdat' etot blok. V <TT>Pool for in-memory object</TT>, razmer etogo
steka sostavlyaet 1/2 <TT>cache_mem</TT>. Razmer <TT>Pool for disk I/O</TT>
zhestko zadan v 200. Dlya <TT>MemObject</TT> i <TT>Request</TT> eto 1/8 velichiny
<TT>FD_SETSIZE</TT>.

<P>Esli Vam nuzhno snizit' kolichestvo pamyati processa, my rekomenduem umen'shit'
maksimal'nye razmery obฎektov v strokah 'http', 'ftp' i 'gopher' konfiguracii.
Takzhe mozhno umen'shit' <TT>cache_mem</TT>. No esli sdelat' <TT>cache_mem</TT>
slishkom malen'kim, to nekotorye obฎekty mogut ne sohranyat'sya na disk pri
bol'shoj zagruzke. Novye versii Squid pozvolyayut zadat' <TT>memory_pools
off</TT> otklyuchaya takim obrazom pul svobodnoj pamyati.
<H3>
<A NAME="6.25"></A>6.25 CHto takoe fqdncache i chem otlichaetsya ot ipcache?</H3>
IPCache soderzhit dannye o preobrazovanii Hostname v IP-Number, a FQDNCache
soderzhit obratnye dannye.

<P>Naprimer:
<PRE>==============================================================================



IP Cache Contents:
šHostnameššššššššššššššššššššš Flags lstrefššš TTLš N [IP-Number]
šgorn.cc.fh-lippe.dešššššššššššššš Cšššššš 0š 21581 1 193.16.112.73
šlagrange.uni-paderborn.dešššššššš Cšššššš 6š 21594 1 131.234.128.245
šwww.altavista.digital.comšššššššš Cššššš 10š 21299 4 204.123.2.75š 204.74.103.37ššš 204.123.2.66ššš 204.123.2.69
š2/ftp.symantec.comššššššššššššššš DLšš 1583 -772855 0šš



Flags:š C --> V keshe
ššššššš D --> Otpravlen
ššššššš N --> Ne keshirovan
ššššššš L --> Blokirovan

lstref: Vremya s momenta poslednego ispol'zovaniya
šš TTL: Time-To-Live (vremya zhizni) poka ne istechet srok hraneniya informacii
šššš N: CHislo adresov



==============================================================================



FQDN Cache Contents:

šIP-Numberššššššššššššššššššš Flags TTL(?) N Hostname]š

š130.149.17.15ššššššššššššššššššš C -45570 1 andele.cs.tu-berlin.de
š194.77.122.18ššššššššššššššššššš C -58133 1 komet.teuto.de
š206.155.117.51šššššššššššššššššš N -73747 0

šFlags: C --> V keshe
ššššššš D --> Otpravlen
ššššššš N --> Ne keshirovan
ššššššš L --> Blokirovan
šš TTL: Time-To-Live
šššš N: CHislo imen</PRE>

<HR>
<H2>
<A NAME="7"></A>7 Troubleshooting</H2>

<H3>
<A NAME="7.1"></A>7.1 Pochemu u menya net dostupa k proksi: "Proxy Access
Denied"?</H3>
Esli <I>squid</I> rabotaet v rezhime httpd-uskoritelya, to vse HTTP zaprosy
on perenapravlyaet na HTTP server, no ne rabotaet kak proksi. Esli Vy hotite,
chtoby Vash kesh takzhe otrabatyval proksi-HTTP zaprosy, nado sdelat' sleduyushchee:

<P><TT>http_accel_with_proxy on</TT>

<P>Takzhe, vozmozhno Vy nepravil'no zadali ACL. Prover'te fajly <I>access.log</I>
i <I>squid.conf</I>.
<H3>
<A NAME="7.2"></A>7.2 Ne rabotaet <TT>local_domain</TT>.</H3>
<I>Squid keshiruet obฎekty iz lokal'nogo domena.</I>

<P>Direktiva <TT>local_domain</TT> ne zapreshchaet keshirovat' lokal'nye obฎekty.
Ona predotvrashchaet ispol'zovanie bratskih keshej dlya lokal'nyh obฎektov.
Esli Vam vse taki eto nuzhno, to vospol'zujtes' opciyami <TT>cache_stoplist</TT>
ili <TT>http_stop</TT> (v zavisimosti ot versii).
<H3>
<A NAME="7.3"></A>7.3 Kogda kesh pytaetsya poluchit' obฎekt s bratskogo kesha,
poluchaet <TT>Connection Refused,</TT> dazhe kogda tot kesh schitaet, chto obฎekt
poluchen uspeshno.</H3>
Esli ICP port vernyj, a HTTP port-net, to ICP zaprosy budut posylat'sya
normal'no, a ICP otvety zastavyat kesh dumat', chto vse v poryadke, no sami
obฎekty budut propadat'. Esli bratskij kesh izmeniit svoj <TT>http_port</TT>,
to u Vas budut te zhe problemy nekotoroe vremya do uvedomleniya.
<H3>
<A NAME="7.4"></A>7.4 Ne hvataet fajlovyh deskriptorov</H3>
|to byvaet, kogda poyavlyaetsya soobshchenie <TT>Too many open files</TT>. Vozmozhno
iz-za operacionnoj sistemy s nizkim chislom fajlovyh deskriptorov. |tot
predel obychno mozhno zadat' v yadre ili pri pomoshchi drugih sredstv. Sushchestvuet
dva puti ischerpat' limit fajlovyh deskriptorov: pervyj, eto limit na kazhdyj
process, vtoroj - na obshchee chislo deskriptorov na vse processy.

<P>Dlya Linux, est' patch <A HREF="http://www.linux.org.za/filehandle.patch.linux">filehandle.patch.linux</A>
ot Michael O'Reilly <A HREF="mailto:michael@metal.iinet.net.au">&lt;michael@metal.iinet.net.au></A>.

<P>Dlya Solaris, dobav'te sleduyushchee v fajl <I>/etc/system</I>:

<P><TT>set rlim_fd_max = 4096</TT>
<BR><TT>set rlim_fd_cur = 1024</TT>

<P>Takzhe sleduet zadat' <TT>#define SQUID_FD_SETSIZE</TT> v <I>include/config.h</I>
v to zhe znachenie, chto i <TT>rlim_fd_max</TT>. Ne sleduet zadavat' men'she
4096.

<P>Solaris <TT>select(2)</TT> pozvolyaet zadat' tol'ko 1024 deskriptora,
esli nado bol'she otredaktirujte <I>src/Makefile</I> i razreshite <TT>$(USE_POLL_OPT)</TT>.
Potom peresoberite <I>squid</I>.

<P>Dlya FreeBSD (ot Torsten Sturm &lt;torsten.sturm@axis.de>):
<DL>
<DT>
Kak uznat' maksimal'noe znachenie fajlovyh deskriptorov?</DT>

<DD>
Po komande <TT>sysctl -a</TT> znachenie <TT>kern.maxfilesperproc</TT>.</DD>

<DT>
Kak ih uvelichit'?</DT>

<DD>
<TT>sysctl -w kern.maxfiles=XXXX</TT></DD>

<BR><TT>sysctl -w kern.maxfilesperproc=XXXX</TT>
<BR><B><I>Vnimanie:</I></B> Uvelichivaya znacheniya, uchityvajte sootnoshenie
<TT>maxfiles > maxfilesperproc</TT>.
<DT>
Kakoj verhnij predel?</DT>

<DD>
YA ne dumayu, chto est' formal'noe ogranichenie vnutri yadra. Ved' struktury
pod dannye vydelyayutsya dinamicheski. Na praktike zhe, mogut voznikat' neponyatnye
yavleniya (naprimer, yadro budet tratit' slishkom mnogo vremeni na poisk v
tablicah).</DD>
</DL>
Dlya bol'shinstva BSD-sistem (SunOS, 4.4BSD, OpenBSD, FreeBSD, NetBSD, BSD/OS,
386BSD, Ultrix) mozhno reshit' zadachu "v lob" (trebuetsya peresborka yadra):
<DL>
<DT>
Kak uznat' maksimal'noe znachenie fajlovyh deskriptorov?</DT>

<DD>
Po komande <TT>pstat -T</TT> znachenie <TT>files</TT>, obychno otobrazhaemoe
kak otnoshenie <TT>current/maximum</TT>.</DD>

<DT>
Kak uvelichit' eto znachenie?</DT>

<DD>
Pervyj metod - uvelichit' znachenie peremennoj <TT>maxusers</TT> v konfiguracii
yadra i peresobrat' ego. |to ochen' bystryj i prostoj metod, no privodit
k uvelicheniyu ryada drugih peremennyh, menyat' kotorye Vam mozhet i ne nado.</DD>

<DT>
A sushchestvuet bolee tochnyj sposob?</DT>

<DD>
Najti fajl <TT>param.c</TT> v ishodnikah yadra i izmenit' sootnoshenie mezhdu
<TT>maxusers</TT> i maksimal'nym chislom otkrytyh fajlov po nizheprivedennym
vyrazheniyam.</DD>
</DL>
Vot neskol'ko primerov:
<DL>
<DT>
SunOS</DT>

<DD>
Izmenite znachenie <TT>nfile</TT> v <TT>/usr/kvm/sys/conf.common/param.c</TT>
menyaya znacheniya v etom vyrazhenii:</DD>

<BR><TT>int nfile = 16 * (NPROC + 16 + MAXUSERS) / 10 + 64;</TT>
<BR>Gde <TT>NPROC</TT> opredelyaetsya kak:
<BR><TT>#define NPROC (10 + 16 * MAXUSERS)</TT>
<DT>
FreeBSD (nachinaya s yadra 2.1.6)</DT>

<DD>
Ochen' pohozhe na SunOS, otredaktirujte <TT>/usr/src/sys/conf/param.c</TT>
vychisliv sootnoshenie mezhdu peremennymi <TT>maxusers</TT>, <TT>maxfiles</TT>
i <TT>maxfilesperproc</TT>:</DD>

<BR><TT>int maxfiles = NPROC*2;</TT>
<BR><TT>int maxfilesperproc = NPROC*2;</TT>
<BR>Gde <TT>NPROC</TT> zadan kak:
<BR><TT>#define NPROC (20 + 16 * MAXUSERS)</TT>
<BR>Ogranichenie chisla deskriptorov na process takzhe mozhet byt' zadano v
konfiguracii yadra etoj direktivoj:
<BR><TT>options OPEN_MAX=128</TT>
<DT>
BSD/OS (nachinaya s yadra 2.1)</DT>

<DD>
Poprav'te <TT>/usr/src/sys/conf/param.c</TT> i zadajte <TT>maxfiles</TT>
v sootvetstvii s:</DD>

<BR><TT>int maxfiles = 3 * (NPROC + MAXUSERS) + 80;</TT>
<BR>Gde <TT>NPROC</TT> zadan kak:
<BR><TT>#define NPROC (20 + 16 * MAXUSERS)</TT>
<BR>Takzhe sleduet zadat' znachenie <TT>OPEN_MAX, </TT>chtoby izmenit' ogranichenie
chisla deskriptorov na process.</DL>
<B>Zamechanie:</B> Posle peresborki yadra neobhodimo otkompilirovat' zanovo
Squid. Konfiguracionnyj skript Squid'a opredelyaet skol'ko fajlovyh deskriptorov
dostupno, tak chto nado zapustit' skript zanovo. Naprimer:
<PRE>ššš cd squid-1.1.x
ššš make realclean
ššš ./configure --prefix=/usr/local/squid
ššš make</PRE>

<H3>
<A NAME="7.5"></A>7.5 Moj <I>squid</I> periodicheski vyvalivaetsya s oshibkoj,
chto ne mozhet <TT>malloc(3)</TT> bol'she pamyati, no u menya dostatochno OZU!</H3>
Krome ogranicheniya na chislo fajlovyh deskriptorov, mnogie sistemy imeyut
ogranichenie na kolichestvo pamyati, vydelyaemoe processu, v osobennosti ne-root
processam. BSD/OS imeet dovol'no nizkij predel, kotoryj Vy mozhete uvelichit'.
Izmenite fajl konfiguracii yadra, dobaviv eti stroki:
<PRE>optionsšššššššš DFLDSIZ=67108864ššššššš # 64 meg default max data size (was 16)
optionsšššššššš MAXDSIZ=134217728šššššš # 128 meg max data size (was 64)</PRE>
Peresoberite yadro i perezagruzite mashinu.š<!-- From:    Ong Beng Hui ongbh@zpoprp.zpo.dec.com -->

<P>V Digital UNIX, otredaktirujte fajl <TT>/etc/sysconfigtab</TT> i dobav'te
stroku...
<PRE>proc:
ššššššš per-proc-data-size=1073741824</PRE>
Ili, v csh, ispol'zuya komandu <TT>limit</TT> ...
<BR><TT>zpoprp.zpo.dec.com> limit datasize 1024M</TT>

<P>Redaktirovanie <TT>/etc/sysconfigtab</TT> trebuet perezagruzki, a komanda
<TT>limit</TT> <TT>- </TT>net.
<H3>
<A NAME="7.6"></A>7.6 CHto za strannye stroki ob udalenii obฎektov?</H3>
Naprimer:
<PRE>97/01/23 22:31:10| Removed 1 of 9 objects from bucket 3913
97/01/23 22:33:10| Removed 1 of 5 objects from bucket 4315
97/01/23 22:35:40| Removed 1 of 14 objects from bucket 6391</PRE>
Obychnye stroki log fajla, no oni ne znachat, chto <I>squid</I> dostig <TT>cache_swap_high</TT>.

<P>Na stranice cache information v<I>cachemgr.cgi</I> najdite stroku tipa
etoj:
<PRE>šššššš Storage LRU Expiration Age:šššš 364.01 days</PRE>
Obฎekty, kotorye ne ispol'zovalis' dannoe kolichestvo vremeni, udalyayutsya
kak rezul'tat regulyarnyh rabot. Vy mozhete zadat' sobstvennoe znachenie <TT>LRU
Expiration Age</TT> pri pomoshchi <TT>reference_age</TT> v konfiguracionnom
fajle.
<H3>
<A NAME="7.7"></A>7.7 Pochemu ya ne mogu zadat' <TT>cache_effective_user</TT>
v <TT>nobody</TT> pod Linux?</H3>
Neskol'ko pol'zovatelej soobshchali, chto oni ne mogut zadat' <TT>cache_effective_user</TT>
v <TT>nobody</TT> pod Linux i server soobshchaet:
<PRE>FATAL: Don't run Squid as root, set 'cache_effective_user'!</PRE>
Odnako, esli ustanovit' <TT>cache_effective_user</TT> ne v <TT>nobody,</TT>
to vse OK. Pervoe reshenie, eto sozdat' pol'zovatelya dlya Squid i ustanovit'
dlya nego <TT>cache_effective_user</TT>.

<P>Takzhe mozhno pomenyat' UID <TT>nobody</TT> s 65535 na 65534.
<H3>
<A NAME="7.8"></A>7.8 Mogu ya ukazat' Windows NT FTP serveru vyvodit' direktorii
v Unix formate?</H3>
Pochemu by i net! Vyberite sleduyushchie punkty menyu:
<UL>
<LI>
Start</LI>

<LI>
Programs</LI>

<LI>
Microsoft Internet Server (Common)</LI>

<LI>
Internet Service Manager</LI>
</UL>
Dvazhdy shchelknite na ftp.

<P>Dal'she nado vybrat' server (dolzhen byt' tol'ko odin), potom vyberite
"Properties" iz menyu, zakladku "directories", budet opciya "Directory listing
style." Vyberite "Unix" type, a ne "MS-DOS" type.
<ADDRESS>
--Oskar Pearson &lt;oskar@is.co.za></ADDRESS>

<H3>
<A NAME="7.9"></A>7.9 Pochemu tak chasto poyavlyayutsya soobshcheniya ERR_NO_CLIENTS_BIG_OBJ?</H3>
|to znachit, chto zaprashivaemyj obฎekt nahodilsya v rezhime "Udalit' pozzhe"
i pol'zovatel' otkazalsya ot peredachi. Obฎekt popadet v rezhim "Udalit' pozzhe"
esli on:
<OL>
<LI>
bol'she, chem <I>maximum_object_size</I></LI>

<LI>
dostavlen s sosednego kesha, u kotorogo ustanovlena opciya <I>proxy-only</I>.</LI>
</OL>

<H3>
<A NAME="7.10"></A>7.10 Pochemu Squid trebuet tak mnogo pamyati!?</H3>
Squid potomu takoj bystryj i mozhet obrabatyvat' odnovremenno neskol'ko
zaprosov, chto ispol'zuet mnogo pamyati. Dlya nachala, prosmotrite eti razdely
FAQ:
<UL>
<LI>
6.12 <A HREF="#6.12">Pool for in-memory objects <B>ogromen</B> i ne stanovitsya
men'she! |to chto utechka pamyati?</A></LI>

<LI>
6.24 <A HREF="#6.24">Kak analizirovat' ispol'zovanie pamyati iz dannyh <I>cachemgr.cgi</I>?</A></LI>

<LI>
7.5 <A HREF="#7.5">Moj <I>squid</I> periodicheski vyvalivaetsya s oshibkoj,
chto ne mozhet <TT>malloc(3)</TT> bol'she pamyati, no u menya dostatochno OZU!</A></LI>
</UL>
Takzhe mozhno povysit' proizvoditel'nost' linkuya Squid s vneshnej malloc bibliotekoj.
My rekomenduem:
<UL>
<LI>
GNU Malloc, dostupnoj na <A HREF="ftp://ftp.gnu.ai.mit.edu/pub/gnu/malloc.tar.gz">ftp://ftp.gnu.ai.mit.edu/pub/gnu/malloc.tar.gz</A>.
Proverka na 'libgnumalloc.a' vklyuchena v konfiguracionnyj skript Squid'a.
Esli libgnumalloc.a najdena, to avtomaticheski podlinkovyvaetsya.</LI>
</UL>

<H3>
<A NAME="7.11"></A>7.11 Pochemu ya poluchayu "Ignoring MISS from non-peer x.x.x.x"?</H3>
Vy poluchaete ICP MISS (cherez UDP) s roditel'skogo ili bratskogo kesha, chej
IP adres Vashemu keshu ne izvesten. |to mozhet byt' v dvuh sluchayah.

<P>(1) Esli na tom konce neskol'ko interfejsov i pakety idut s togo, kotoryj
ne propisan v DNS. Voobshche-to, eto ih problema. Vy mozhete skazat' im ili
propisat' IP adres interfejsa v DNS, ili ispol'zovat' opciyu Squid 'udp_outgoing_address'.

<P>Naprimer:
<PRE># (squid.conf roditel'skogo kesha)
#
udp_outgoing_address proxy.parent.com


# (Vash squid.conf)
#
cache_host proxy.parent.com parent 3128 3130</PRE>
(2) Takzhe eto soobshchenie budet poyavlyat'sya pri posylke ICP zaprosov na neskol'ko
adresov. Dlya obespecheniya bezopasnosti, Squid trebuet zadaniya v konfiguracii
spiska drugih keshej, slushayushchih gruppu adresov. Esli neizvestnyj kesh slushaet
etot adres i shlet otvety, vash kesh budet pisat' v log eti soobshcheniya. CHtoby
ispravit' nado, libo skazat' etomu keshu perestat' slushat' adresa, ili,
esli on zakonnyj, dobav'te ego v fajl konfiguracii.š
<HR>
<H2>
<A NAME="8"></A>8 Kak Squid rabotaet?</H2>

<H3>
<A NAME="8.1"></A>8.1 Kakie obฎekty keshiruyutsya?</H3>
Obฎekty Internet takie kak fajl, dokument, ili otvet na zapros sleduyushchih
servisov: FTP, HTTP, ili gopher. Klient zaprashivaet obฎekt Internet s keshiruyushchego
proksi, proksi server poluchaet obฎekt (libo s hosta, ukazannogo v URL,
libo s roditel'skogo ili bratskogo kesha), perepravlyaya ego klientu.
<H3>
<A NAME="8.2"></A>8.2 CHto za protokol ICP?</H3>
ICP eto protokol ispol'zuemyj dlya obshcheniya keshej squid. ICP protokol opisan
v Internet Cache Protocol, 2 proekte dokumenta, nahodyashchemsya po adresu <A HREF="http://www.nlanr.net/Cache/ICP/ICP-id.txt">http://www.nlanr.net/Cache/ICP/ICP-id.txt</A>.

<P>ICP prezhde vsego ispol'zuetsya v ierarhii keshej dlya poiska opredelennyh
obฎektov v bratskih keshah. Esli squid ne nahodit nuzhnogo dokumenta, to
posylaet ICP zapros bratskim kesham, kotorye v svoyu ochered' otvechayut ICP
otvetami "HIT" ("popadanie") ili "MISS" ("promah"). Zatem kesh ispol'zuet
otvety dlya vybora pri pomoshchi kakogo kesha razreshat' svoi otvety MISS.

<P>ICP takzhe podderzhivaet slozhnye peredachi mnozhestva obฎektov cherez odno
TCP soedinenie. ICP sejchas rabotaet poverh UDP. Tekushchie versii Squid takzhe
podderzhivayut mnozhestvennye zaprosy ICP.
<H3>
<A NAME="8.3"></A>8.3 CHto takoe <I>dnsserver</I>?</H3>
<I>Dnsserver</I> eto process iniciiruemyj <I>squid</I> dlya preobrazovaniya
domennyh imen v IP adresa. Neobhodimost' voznikaet iz-za togo, chto funkciya
<TT>gethostbyname(3)</TT> blokiruet vyzyvayushchij process do zazresheniya DNS
zaprosa.

<P>U Squid ne dolzhen blokirovat'sya process vvoda/vyvoda, poetomu DNS obrashcheniya
vypolneny kak vneshnij k osnovnomu process. Processy <I>dnsserver</I> ne
keshiruyut zaprosy DNS, eto delaetsya samim <I>squid`om</I>.
<H3>
<A NAME="8.4"></A>8.4 Dlya chego nuzhna programm<I>ftpget</I>?</H3>
Programma <I>ftpget</I> eto FTP klient, ispol'zuyushchijsya dlya skachivaniya fajlov
s FTP serverov. Iz-za togo, chto FTP protokol neprostoj, proshche vypolnit'
ego otdel'no ot osnovnogo koda <I>squid</I>.
<H3>
<A NAME="8.5"></A>8.5 FTP PUT ne rabotaet</H3>
<I>Pohozhe,chto FTP put ne rabotaet cherez squid. Mozhno li kak-nibud' eto
ispravit' i/ili vedetsya li kakaya-nibud' rabota v etom napravlenii.</I>

<P>Na dannyj moment net, dlya podderzhki etogo nuzhna budet programma <I>ftpput</I>.
<H3>
<A NAME="8.6"></A>8.6 CHto takoe ierarhiya keshej? CHto takoe roditel'skie
i bratskie keshi?</H3>
Ierarhiya keshej eto struktura keshiruyushchih proksi-serverov raspolozhennyh logicheski
kak roditel'skij/dochernij i bratskij uzly, takim obrazom, chto keshi blizhajshie
k kanalu v Internet yavlyayutsya roditelyami tem, kotorye nahodyatsya dal'she ot
tochki vhoda v Internet. Roditel'skie keshi obrabatyvayut "promahi" dochernih.
Inache govorya, kogda kesh zaprashivaet obฎekt s roditelya, i u togo v keshe
ego ne okazyvaetsya, roditel'skij kesh skachivaet obฎekt, keshiruet ego, i
peredaet dochernemu. Takim obrazom, pri pomoshchi ierarhii dostigaetsya maksimal'naya
razgruzka kanala, snizhaetsya ispol'zovanie vneshnih serverov Internet i poluchaetsya
bol'shee chislo "popadanij" dochernih keshej, po sravneniyu s roditel'skimi,
za schet bol'shego kesha poslednih.

<P>Krome roditel'skih/dochernih otnoshenij, squid podderzhivaet ponyatie bratskih
keshej, to est' nahodyashchihsya na odnom urovne ierarhii, prizvannyh raspredelit'
nagruzku. Kazhdyj kesh v ierarhii nezavisimo ni ot kogo reshaet otkuda brat'
obฎekt, libo s servera v Internet, libo s roditel'skogo ili bratskogo kesha,
ispol'zuya prostoj mehanizm razresheniya. Bratskie keshi ne budut zabirat'
obฎekt dlya drugogo kesha togo zhe urovnya, poluchiv ot nih "promah".
<H3>
<A NAME="8.7"></A>8.7 Kakov algoritm razresheniya kesha Squid?</H3>

<OL>
<LI>
Razoslat' ICP zaprosy vsem sootvetstvuyushchim bratskim kesham</LI>

<LI>
Dozhdat'sya vseh otvetov, prishedshih v techenie zadannogo vremeni (po umolchaniyu
dve sekundy).</LI>

<LI>
Poluchiv pervyj otvet HIT nachat' skachivanie obฎekta , ili</LI>

<LI>
Vzyat' obฎekt s pervogo roditel'skogo kesha, otvetivshego MISS (zavisit ot
vesovyh koefficientov), ili</LI>

<LI>
Zabrat' obฎekt iz Internet</LI>
</OL>
Algoritm stanovitsya otchasti bolee slozhnym pri vklyuchenii v shemu brandmauera.

<P>Direktiva <TT>single_parent_bypass</TT> predotvrashchaet rassylku ICP zaprosov,
v sluchae kogda sootvetstvuyushchij bratskij kesh eto roditel'skij (to est',
esli bol'she neotkuda brat' obฎekt, zachem naprasno zaprashivat'?)
<H3>
<A NAME="8.8"></A>8.8 Nad kakimi vozmozhnostyami Squid razrabotchiki sejchas
rabotayut?</H3>
Est' neskol'ko otkrytyh proektov kasayushchihsya luchshego avtomaticheskogo vyravnivaniya
nagruzki, takzhe (dinamicheskogo i staticheskogo) vybora roditel'skih keshej,
routinga, mnozhestvennyh kesh-kesh obrashchenij i luchshego raspoznavaniya URL,
kotorye ne nado keshirovat'.

<P>Tekushchij spisok budushchih vozmozhnostej, dostupen zdes' <A HREF="http://squid.nlanr.net/Squid/Devel/todo.html">http://squid.nlanr.net/Squid/Devel/todo.html</A>.

<P>Razrabotchikam budushchih versij sleduet obratit'sya syuda <A HREF="http://squid.nlanr.net/Squid/Devel/">http://squid.nlanr.net/Squid/Devel/</A>.
<H3>
<A NAME="8.9"></A>8.9 Gde najti informaciyu o zagruzke Internet trafika</H3>
Zagruzku mozhno oharakterizovat' kak tyazhest' vozlagaemaya pol'zovatelem ili
gruppoj pol'zovatelej na sistemu. Ponimanie prirody zagruzki ochen' vazhno
pri upravlenii proizvoditel'nost'yu sistemy. Esli Vy interesuetes' zagruzkoj
Internet trafika, to dlya nachala shodite syuda <A HREF="http://www.nlanr.net/NA/">http://www.nlanr.net/NA/</A>.
<H3>
<A NAME="8.10"></A>8.10 Kakie preimushchestva keshirovaniya sovmestno s keshiruyushchej
sistemoj NLANR?</H3>
Preimushchestva ierarhicheskogo keshirovaniya zaklyuchayutsya v snizhenii zagruzki
kanala, umen'shenii vremeni dostupa, luchshej ustojchivosti k sboyam. Keshi verhnego
urovnya obsluzhivayut zaprosy nizhestoyashchih..Esli srednij procent popadaniya
kraevogo kesha 50%, polovina vseh ssylok kraevyh keshej dolzhna obrabatyvat'sya
cherez kesh vtorogo urovnya, nezheli napryamuyu s ishodnogo hosta. Esli etot
kesh vtorogo urovnya soderzhit bol'shinstvo zaprashivaemyh dokumentov, to vyigrysh
dostigaetsya, no esli kesh verhnego urovnya chashche vsego ne imeet nuzhnyj dokument,
ili peregruzhen, to vremya dostupa vmesto snizheniya uvelichivaetsya.
<H3>
<A NAME="8.11"></A>8.11 Gde najti informaciyu po brandmaueram?</H3>
Smotrite spisok rassylki i FAQ zdes' <A HREF="http://www.greatcircle.com/firewalls/">http://www.greatcircle.com/firewalls/</A>š
<HR>
<ADDRESS>
$Id: footer,v 1.3 1997/03/13 16:19:52 wessels Exp $</ADDRESS>