Squid Implementing Transparent Network Caching System with Squid

Transcription

1 Squid Implementing Transparent Network Caching System with Squid lbhsieh@cc.csit.edu.tw placing tremendous demands on the Internet. A World-Wide-Web key strategy for scaling the Internet to meet these increasing demands is to cache data near clients WWW Server and thus improve access latency and reduce network and server load[1]- [3]. Transparent network caching automatically web proxy cache server cache intercepts requests for Web content along routing access paths from clients to servers, and diverts these to latency WWW Server local web proxy cache server for services. There is cacheno need for any client or browser reconfiguration web caching becomes an integral part of the network. A proxy cache server Transparent transparent network cache behaves as the origin caching HTTP server it responds to the client using the IP webproxy cache server(s)address of the origin server. The client is unaware that it is connected to a network cache instead of Squid NLANR web cache server the origin server. This makes it an attractive management practice for which the users do not Squid Transparent have to configure their browsers to us caching. Caching squid box as gateway This paper discussed three methods policy-based IP routing switch-based transparency implementing transparent network caching system: Layer 4/7 switching squid box as gatewaypolicy-based IP routing and FreeBSD Cache Box Linux Cache Box switch-based transparency (Layer 4/7 switching). TANet ADSL The last two methods were actually implemented Multi-Homed scalable at Cheng Shiu Institute of Technology. Our fail-safe experience in implementing those techniques was presented, along with the design of multi-homed WWWWeb Proxy CacheTransparent campus network with TANet and ADSL CachingSquidLayer 4/7 Switch connection. Keywords: WWW Web Proxy Cache Abstract Transparent CachingSquidLayer 4/7 Switch The growing popularity of the World Wide Web is 311

2 World-Wide-Web object cache TANet cache server HTTP TANet internet cache TANet server NetCache CacheFlow WWW Proxy Cache Server Application Specific OS File Structure cache server cache cache access latency WWW Server Web Proxy Cache Server Server HTTP port 80 Squid transparent cache server Squid Squid Transparent caching HTTP port 80 web proxy cache server(s) Squid Network Appliance NetCache CacheFlow Inc.CacheFlow policy-based IP routingswitch-based TransparencyLayer 4/7 switching port 80 IP Transparent caching cache Web Server Compile Squid HTTP network cache promiscuous Proxy Cache Server Squid web-requests scalable fail-safe proxy-specific URL web cache server HTTP Proxy Cache Server redirectcache cache NLANR web cache server--squid HTTP cache server gateway Code Red TANet WEB scalability fail-safe proxy http request HTTP deny proxy 312

3 Cache Server web Transparent Caching server cache server Transparent web-requests proxy-specific Caching URL Scalable Fail-Safe Squid cache Squid http web-requests internet cache server proxy-specific Squid single point failure server Squid Squid Box as Squid Layer 4/7 switch a Gateway Transparent Cache Scalable Fail-Safe Squid Box as a Gateway FreeBSD 3.0 FreeBSD Gateway /etc/ipnat.rules # Redirect direct web traffic to local web Gateway IPFilter server. HTTP rdr de /32 port 80 -> port 80 default gateway tcp FreeBSD # Redirect everything else to squid on port 3128 Router To Internet rdr de /0 port 80 -> port 3128 Non-HTTP Traffic HTTP tcp Squid port Port Squid port IPNAT ipnat Port 3128 SQUID FreeBSD Kernel /sbin/modload /lkm/if_ipl.o FreeBSD Gateway /sbin/ipnat-f /etc/ipnat.rules chgrp nobody /dev/ipnat Incoming Traffic Cache Box chmod 644 /dev/ipnat IPFILTER FreeBSD3.0 IPFIREWALL ipfw FreeBSD FreeBSD options IPFIREWALL ipnat port 80 port options IPFIREWALL_FORWARD 3128 HTTP IP Firewall deny Router internet /etc/rc.local http SquidSquid ipfw add 600 allow all from any to any promiscuous ipfw add 49 allow tcp from to 313

4 any ipfw add 50 fwd ,3128 tcp from any to any 80 Request Non HTTP Traffic Router with Policy Routing To Internet Rule FreeBSD Cache Box IP Squid port 3128 rule 50 HTTP 3128 Traffic configure./configure enable-ipf-transparent Port 80 Squid IPCHAINS squid.conf http-accelerator Port 3128 Linux Kernel web-requests proxy-specific Cache Box httpd_accel_host virtual httpd_accel_port 80 httpd_accel_with_proxy on httpd_accel_uses_host_header on router access-list http redirect cache box Cisco FreeBSD router 2600 access-list 110 deny tcp host FreeBSD any eq www!llinux Cache Box IP: internet fail-safe access-list 110 permit tcp any any eq www Policy-Based IP Routing route-map proxy-redirect permit 10 Border Access match ip address 110 Router HTTP Squid set ip next-hop internet Router Router!routerethernet port Cisco Router policy policy routing HTTP Linux ip policy route-map proxy-redirect cache box HTTP internet Router port 80 Cache Box ipchains port 80 forward Squid port 3128 promiscuous http accelerator Ipchains router port 80 redirect Squidport 3128 RedHat Linux 7.0 ipchains Firewall Squid cache client redirection cache hit Router internet client cache echo 1 >/proc/sys/net/ipv4/ip_forward! IP-forwarding ipchains A input j REDIRECT 3128 p tcp s /0 d /

5 httpport 80Squid port 3128 cache server cache server configure./configure 9GB U2W SCSI Adaptec U2W SCSI enable-ipf-transparent Squid cache server squid.conf http-accelerator core switch transparent web-requests proxy-specific httpd_accel_host virtual httpd_accel_port 80 httpd_accel_with_proxy on httpd_accel_uses_host_header on caching cache server cache server router WCCPWeb Cache Communication Protocol Cisco OS version 11.3 WCCP Cisco version 2 open policy routing version 11.3 protocol http IOS cache server scalability load router cache server balancing WCCP router Squid Fail-Over cache guard query cache server cached Switch-Based SNMP router Multi-Homed Transparent Caching redirect port 80 FreeBSD Cache Box Cisco 2600 Switch-Based Transparent Router Caching transparent caching proxy Layer 4(L4)Layer 7(L7) cache server IBM Netfinity 3000 ServerPII 450MHz CPU768MB RAM9GB Ultra II Wide(U2W) OSI-Reference Model Transport Layer Application Layer L4 SCSI MRTG TCP UDP header port # pwebstats hit rate socket # L7 URL L4 L7 L4 Cisco 2600 router cpu L4/L7 QoSIP Filter core switchfoundry BigIron server load balancing ASIC wire-speed 4000 L4/L7 hash TCP MRTG pwebstats session hash bucket hit rate Web server URL cache server cache farm cache Cisco 2600 router web content cache 315

6 load balancing L4/L7 ADSL ISP Scalable server load balancing ADSL Health Check ADSL Server Cluster Server Farm proxy cache fail-safe L4 L7 IP Router TCP port# 80 cache TANet box http wire-speed FE To T1*2 switch L2 MAC switchingrouter L4/7 Switch internet cache box operating system Squid transparent caching GE FreeBSD Linux Cache Box L4/7 switch L3 Core Switch Configuration Guide L4/L7 switch ADSL*2 HiNet Health Check Cache Box L4/L7 switch forward cache box Multi-Homed MACLayer 2switching cache server Switch-Based Multi-Homed L4/L7 switch switch Transparent Caching cache server cache serve L4/L7 switch forward Cache Group Cache Fail-Safe keep-alive Serversload balance Weighted server Weight Router Non HTTP Traffic To Internet proxy cache server Request L4/L7 Switch HTTP TANet WWW Proxy Cache Server Port 80 Port 3128 Squid access latency WWW Server Cache Box Switch-Based Transparent caching 316

7 HTTP [8] web proxy cache server(s) cache [9] TANet2000 Squid [10] [11] FreeBSD Cache Box Linux Cache [12] Enable Fast-Switched Policy Routing, Box Network Protocols Configurations Guide, Part TANet ADSL Multi-Homed 1, Cisco Systems, San Jose, California, 1997 scalable fail-safe [13] [14] [15]The Internet Protocol Journal, Vol.2, Number L4/L7 Switch cache server 3, September 1999 [16] [1] Bradely M. Duska,David Marwood, and Michael J. ml [17] Cisco Content Services Switch Advanced Configuration Guide, Cisco Inc., June 2001 Feeley, The Measured Access Characteristics of [18] Foundry ServerIron Installation and World-Wide-Web Client Proxy Caches, Configuration Guide, Foundry Networks, Proceedings of the USENIX Symposium on Internet Technologies and Systems, December March, 2001 [19] [2] Peter Danzig, Mike Schwartz, and Richard Hall, A Case for Caching File Objects inside Internetworks, ACM SIGCOMM 93, 1993 [3] Scalable WWW Proxy Server TANet 99 [4] ISP Caching Deployment Guide, Cache Flow Inc., 1998 [5] Peter Danzig NetCache Architecture and Deployment,Computer Networks and ISDN Systems, Vol.30 PP , 1998 [6] Peter Danzig and Karl L. Swartz, Transparent, Scalable, Fail-Safe Web Caching, Technical Report TR-3033, Network Appliance Inc., Santa Clara, California, U.S.A., 2001 [7] Implementing Transparent Caching Using Squid, Kovai Solutions USA Inc.,