What Are APAN Services? WWW –apan.net and www.apan.net DNS –ns.kaist.apan.net and ns.jp.apan.net E-mail/mailing lists –apan.net Distributed among/operated by APAN- KR/ANF and APAN-JP NOCs
Why Revisiting? These are the most important services for us –to get information from APAN thru WWW –to communicate with others thru e-mail/mailing lists –based on the APAN DNS So they need –correctness of information –reliability and stability of operation/monitoring And they are naturally based upon the network architecture/operation. Now APAN network architecture/operation has changed greatly which requires revisiting the services. –24x7 operation/monitoring –GbE connection between JP and KR
(Previous) Problems WWW –Contents of apan.net(KR) and www.apan.net(JP) have 4 hours difference -> Harmful DNS –No backup of primary database(KR) -> Dangerous E-mail/mailing lists –No backup of mailing lists(KR) -> Dangerous Operated/monitored jointly by APAN-KR/ANF and APAN-JP NOCs –No 24x7 operation/monitoring on KR side
New Scheme Servers distributed among JP and KR –Controlled/operated/monitored by APAN NOC –Redundancy/reliability Information correctness, reliability, and stability –NFS between servers for WWW –Backup of data for WWW, DNS, Mailing Lists –Servers location independence of the sec.
Current Status/Follow-up WWW servers, apan.net = www.apan.net –2 official servers(JP and KR) with 1 hidden server(master.apan.net in Sec./TH) Sec controls the contents –Hidden server is rcynced by JP server (with a reliable backup) in every 4 hours Sec must have a way to trigger rsync –KR server NFS-mounting JP server contents KR must have a local copy : local copy of NFS-mounted contents –Need performance test for this scheme DNS servers –Primary server moved to APAN NOC from KAIST, but its hidden now –The same 2 servers(secondary) seen from outside –1 hidden server + 2 servers or just 2 servers? Mail server/mailing lists reconfiguration –Still pending Should follow WWW servers scheme – 2 official mail exchangers Sec must control ML lists Is it worth trying anycast for these services?
Current Status on KR Side KOREN/APAN-KR NOC has moved to Seoul with servers –I(JH Lee) am working for Convergence Lab., KT in Seoul Our new servers (still going on) –2 redundant 1-u servers for WWW, DNS, mail servers w/ storage servers These will host the APAN servers/services –Planning to have specialized servers for tunnel broker, AG bridge servers, SNMP servers, etc. Only in 6 years were going to have many new servers
Web Contents THJPKR noc6-5.kr.apan.net = apan.net = www.apan.net 22.214.171.124 ns2.jp.apan.net = apan.net = www.apan.net 126.96.36.199 master.apan.net 188.8.131.52 Mounted with NFS Real-time updating can be done Synchronizing the contents by SSH-wrapped rsync every 4 hours apan.net A 184.108.40.206 A 220.127.116.11 www CNAME apan.net. Master:18.104.22.168Slave:22.214.171.124 Users can access JP or KR server using http://apan.net/ or http://www.apan.net/. The result of DNS query determines which server will be selected. Domain Name Servers of apan.net Results of DNS query are round robin. 1 st time %nslookup apan.net Name: apan.net Addresses: 126.96.36.199, 188.8.131.52 2 nd time %nslookup apan.net Name: apan.net Addresses: 184.108.40.206, 220.127.116.11 3 rd time %nslookup apan.net Name: apan.net Addresses: 18.104.22.168, 22.214.171.124 Secretariats can edit and update web contents on master.apan.net. This crontab with script on JP server remotely runs rsyncd command wrapped by SSH every 4 hours. Then rsync checks the updated contents on master.apan.net and transfers them to JP server. These A records and CNAME record realize round robin service. Previous rsync configuration between old KR server and JP had deleted. Old KR web server $ cat rsyncd.conf hosts allow = 126.96.36.199 use chroot = no max connections = 4 syslog facility = local5 # pid file = /var/run/rsyncd.pid timeout = 6000 [www] path = /usr/local/src/www/html/apan.net lock file = /home/inetapan/rsyncd.lock uid = inetapan gid = users read only = true This rsyncd.conf on master.apan.net allows rsync accessing from JP server. Web Contents Figure of APAN Web Servers Relocation by Mr.Hattori JHLee-san sent CD-Rs to Pensri-san. They contain the whole web contents of apan.net. And Pensri-san has uploaded them on master.apan.net. %crontab –l 20 */4 * * * /usr/home/httpd/cron/wwwsync/wwwsync.sh %cat /usr/home/httpd/cron/wwwsync/wwwsync.sh #!/bin/sh /usr/local/bin/rsync -e ssh -aqz firstname.lastname@example.org::www /home/httpd/www.apan.net Master:188.8.131.52
Redundancy for Web Service How to build redundancy for http://apan.net/ a nd http://www.apan.net/ –Synchronize contents from TH to JP and from JP to KR –Allocate 2 IP addresses (KR:184.108.40.206 and JP:203.18 1.248.30) for apan.net and www.apan.net –Use round robin DNS How to synchronize the web contents –The bandwidth and RTT of TH-JP and KR-JP are taken into account –KR-JP use NFS, enough bandwidth and good RTT –TH-JP use SSH-wrapped rsync because of limited bandwidt h
Building KR-JP Synchronization by NFS NFS for synchronization between KR and JP, an d he led the implementation –NFS has already showed enough performance within Korea –Fortunately, there is enough bandwidth between KR a nd JP –JP server, exports the web contents as read-only NFS server only to KR server –KR server remotely mounted them as NFS client Destination is from JP to KR Need further tests for NFS/WWW performance
New Services NTP Information/Routing Registry H.323/SIP APAN Observatory LDAP … Any services members want to have
Now comes the detailed report of the APAN services relocation by APAN/APAN- JP NOC