Bijayant Kumar --- On Thu, 31/7/08, Amos Jeffries <squid3@xxxxxxxxxxxxx> wrote: > From: Amos Jeffries <squid3@xxxxxxxxxxxxx> > Subject: Re: Some queries about cache_peer > To: bijayant4u@xxxxxxxxx > Cc: "squid users" <squid-users@xxxxxxxxxxxxxxx> > Date: Thursday, 31 July, 2008, 5:09 PM > bijayant kumar wrote: > >> From: Amos Jeffries <squid3@xxxxxxxxxxxxx> > >> Subject: Re: Some queries about > cache_peer > >> To: bijayant4u@xxxxxxxxx > >> Cc: "squid users" > <squid-users@xxxxxxxxxxxxxxx> > >> Date: Thursday, 31 July, 2008, 9:31 AM > >>> Hello list, > >>> > >>> I tried to set up cache_peer, but i could not > >> understand that it has setup > >>> or not. Please give some inputs. > >>> > >>> Scenario:- > >>> > >>> I have setup three proxy-servers.squid 3.0.7 > Stable > >>> proxy1 192.168.99.134 > >>> proxy2 192.168.99.135 > >>> proxy3 192.168.99.121 > >>> > >>> Lan Computer 192.168.99.23. > >>> > >>> On my Lan Computer, i have configured proxy in > my > >> browser as > >>> 192.168.99.134 ie proxy1. All request first go > to > >> proxy1. > >>> In Proxy1 squid.conf:- > >>> cache_peer 192.168.99.135 parent 3128 > 3130 > >> proxy-only default > >>> cache_peer 192.168.99.121 parent 3128 > 3130 > >> proxy-only > >>> cache_peer_domain 192.168.99.135 .com > >>> cache_peer_domain 192.168.99.121 .net > >>> > >>> In proxy2 and proxy3 no cache_peer is > configured. > >>> > >>> I can browse the web. But i didnt understand > the > >> working. I have some > >>> queries regarding this scenario: > >>> If the page is not in any of the proxy server, > then > >> which proxy server > >>> will go to internet and fetch for the user. I > mean if > >> user access any > >>> ".net" domain then the request will > come to > >> the proxy1 first, it will > >>> query to the proxy3, if its there it will be > delivered > >> else the page will > >>> be fetched from the internet ,Same is for the > >> ".com" domain right? > >> > >> Usually. If netdb/icmp has been enabled squid will > keep > >> records of > >> response times and go to whichever of peer/web > responds > >> fastest. thinking > >> fastest available service is usually best to use. > >> > >> Check your access.log for info on which is being > selected > >> for each request. > >> > >>> Then my question is, > >>> 1) which server will query to the internet for > the > >> page which is not in > >>> the cache ie ".net" dedicated server > or the > >> main proxy1 server? > >> > >> Under only cache_peer_domain, maybe both. Use > >> 'never_direct' to force > >> requests to go via peers. > >> > > If i use 'never_direct' option then if parent > cache servers will go down then no body will be able to > browse the web. And if i will not use 'never_direct' > option then fetching of object will be done by proxy1,if > object not found in any cache(proxy2/proxy3), am i right? > > Yes. > > > > >>> 2) The new page will be written to the which > cache, > >> proxy1 or > >>> proxy2/proxy3 > >> 'proxy-only' prevents caching at proxy1 if > request > >> came from peer. If > >> request came from web DIRECT then it can be cached > at > >> proxy1 and used > >> later. > > In my configuration, proxy1 will query to the internet > for new objects and hence the cache will be populated of > proxy1 only, no matter it is of ".net" domain or > of ".com" domain. Then the new entry of > ".net" and ".com" domain will never be > written to the cache of the dedicated caching server for the > same. > > If i am right in my analogy then can you please > suggest me to how to avoid this situation. I mean that > ".net" cache will be written to ".net" > dedicated server(proxy3) and ".com" cache will be > written to the proxy2. > > In squid you only have a choice of peers vs DIRECT. > > Your config earlier was workable, in which case squid will > make that > choice every request. Usually going peers, but sometimes > going DIRECT. > > Or you can force a choice yourself with never_direct > (opposite is > always_direct, but its clear to me you don't want > that). > > It's up to you. > > To decide if a cache of 100% .com traffic is worth the > small risk of no > access to .com at all when proxy2 goes down. Which is only > 2x the same > risk of proxy1 going down by itself anyway. > > Keeping in mind that a quick admin reconfigure of proxy1 > (commenting out > the proxy2 lines) can restore access while proxy2 is > debugged about why > it went down. > It means that this configuration will not serve my purpose of using cache_peer. I also can not afford of any down time also. I wanted to use proxy servers in my network which are 2 to 3 in numbers, share their cache among them. To achieve this setting shall i use DNS round robin or squid round robin along with the cache_peer settings in all the three server's squid.conf ? Can you give me some input to achieve this, it would be great help. Thanks & Regards Bijayant > Amos > -- > Please use Squid 2.7.STABLE3 or 3.0.STABLE8 Send instant messages to your online friends http://uk.messenger.yahoo.com
