Squids

Revision as of 22:29, 18 December 2004

• Current squid machines: browne, maurus, rabanus, will

• to add new IPs for squid:
  • add the IPs in /var/named/master/wikipedia.zone in the obvious places (on zwinger)
  • make sure to update the serial number in the zone file!
  • run rndc reload to make it update - no need to restart named

• some useful commands:
  • dig ANY en.wikipedia.org @zwinger.wikipedia.org
  • dig +short ANY en.wikipedia.org

IPs of virtual ethernet interfaces

• to find out the IPs, run host en.wikipedia.org and host cache.wikimedia.org
• Used to be assigned at boot time, but this can lead to problems with duplicated IP addresses.
• According to damyta, should use 255.255.255.255 for netmask for the IPs of virtual eth interfaces - otherwise there can be routing confusion.
  • We've been using this configuration for months now and it works fine. -- Jeronim 10:41, 19 Sep 2004 (UTC)
• You must ping through the switch via a virtual interface which you have just brought up (using ping -I), to update the switch's idea of who has what IP. When pinging with -I207.142.131.248 or similar, use suda as the ping target; pinging the broadcast address does not always work.
  • Can use script takeip in /home/wikipedia/bin to take over an IP if a squid goes down.
  • To take down a virtual eth interface, /sbin/ifconfig eth0:n down
  • TODO: set up heartbeat for automatic IP takeover.

Things to check when it goes crazy

• check to see if access.log (probably in /var/log/squid) has reached 2GB in size. If it has, logrotate it or at least rename it.

Logs

Currently on yongle in /var/backup/archiv, and/or on zwinger in /home/wikipedia/logs/archiv/

French squids

• Hardware
  • 3 600MHz Celeron 1U machines with 20GB HDD and 128MB RAM (now upgraded to 640MB) - HP Web Hosting Server Appliance sa1100 - specs: [1]
  • 2 serial ports, 2 NICs, no graphics card
  • Debian
• Network connectivity
  • Dexlan 5-port switch (port 1=uplink, ports 2-4=squids, port 5=free); all cables straight;
  • names are chloe (212.85.150.132), bleuenn (212.85.150.133), and ennael (212.85.150.131);
  • addresses 212.85.150.130 and 212.85.150.134 may also be used to connect other machines (laptop for maintenance...);
• null-modem serial cables run from ttyS1 on one machine to ttyS0 on another; getty running on ttyS0 on each machine, to allow communication using minicom; order (caller to listener) is chloe → ennael → bleuenn → chloe;
• rack space provided by Lost Oasis inside the Telecity colocation in Aubervilliers near the northern city limits of Paris.
• Contact: Med

New squid setup

#!/bin/sh
echo 'getting squid from browne'
scp -r  root@browne.wikimedia.org:/usr/local/squid /usr/local
echo 'getting config'
scp -r  root@zwinger.wikimedia.org:/home/gwicke/squid/newsquid.conf /usr/local/squid/etc/squid.conf
echo 'create a shortcut to /usr/local/bin/squid'
ln -s /usr/local/squid/bin/RunCache /usr/local/bin/squid
#squid user/group is already existing on all servers
#echo 'setting up the squid user'
#adduser --system --no-create-home --disabled-login squid
#echo 'setting up the squid group'
#addgroup --system --no-create-home squid

echo 'creating /var/spool/squid and /var/log/squid'
mkdir /var/spool/squid
chown -R squid:squid /var/spool/squid
mkdir /var/log/squid
chown -R squid:squid /var/log/squid
mkdir /var/log/squid/outgoing
chown -R squid:squid /var/log/squid/outgoing
echo 'edit the configuration'
vim /usr/local/squid/etc/squid.conf
echo 'initializing cache dirs'
/usr/local/squid/sbin/squid -z

echo 'getting log rotation scripts'
scp root@zwinger.wikimedia.org:/home/gwicke/squid/crontab /root
scp root@browne.wikimedia.org:/usr/local/bin/preplogs_for_move /usr/local/bin/preplogs_for_move
scp root@browne.wikimedia.org:/etc/logrotate.d/squid /etc/logrotate.d/squid
# don't overwrite root's crontab, as there maybe something important in there
# crontab -u root /root/crontab

• log transfer from /var/log/squid/outgoing/* to /home/wikipedia/logs/incoming/{hostname}/

to investigate

• Selectively remove Squid-2 cache contents: http://www.wa.apana.org.au/~dean/squidpurge/