Apaches

Revision as of 07:14, 17 July 2006

Restarting

All

Connect to zwinger and type apache-graceful-all. If you see permission denied or a password request, say which server name appears in the error message or password request in the IRC channel and one of the roots will add you to that server.

One, to test a change

Either connect to zwinger and ssh wherever or connect to the web server you want to test on. Then type apache-graceful to restart apache on that web server only. Test your change with telnet, as with this foundation example, with what you type in italics:

telnet localhost 80
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
GET /fundraising HTTP/1.1
Host:wikimediafoundation.org
(an empty line)

The raw HTML for the page will now be displayed in your window. You can copy and paste that into a file on your hard drive and open it with your browser to see the effect. Host is the name of the web site after the http:// part in your browser URL area. GET /fundraising is the part after the site name. The example gets http://wikimediafoundation.org/fundraising.

Restarting httpd

If httpd is broken, sudo apache-restart to restart a single httpd. Use dsh to apply it to all. If you get hundreds of instances counted by ps aux|grep httpd|wc -l and the server is having problems you might need to do this.

Starting load-balancing ICPAgent

This is started automatically when the computer restarts and is necessary for the Apache to take any work. To start:

• use /usr/local/bin/icpagent, has the right timings for each host

Stopping load-balancing ICPAgent

If you need to take the load from this Apache use either:

• killall icpagent as root
• remote management? as a member of group wikidev

Logging

Text output on stderr from various external commands, as well as some apache errors, are in /apache/logs/error_log on each server. PHP errors are in /apache/logs/php-errors . Most apache error messages, such as file not found errors, are in hostname-error_log, for example /apache/logs/en.wikipedia.org-error_log .

Apache access logs are mostly disabled. Webalizer statistics are made using the squids logs instead.

Apache setup checklist

1. From the bastion host, run: cd /home/wikipedia/src/packages && ./bootstrap <HOSTNAME> setup-apache. This will set up SSH host keys and NFS mounts and install NTP, LDAP, Apache, PHP, MW and lots of other good stuff. It sets up the sysctls and IP addresses for LVS use, and starts apache. Thus it gets a host from the state Kyle typically leaves it in after a reinstall, to an apache actually in the pool, in one simple command. It is rerunnable, so if anything goes wrong, just edit he script and run it again. The only other thing left to do is to update the various host lists.
2. Add the host to /usr/local/dsh/node_groups/apaches and mediawiki-installation
3. scp /usr/local/dsh/node_groups/apaches root@dalembert:/usr/local/etc/
4. ssh root@dalembert ; screen -r ; break lvsmon and start it again
5. cd /home/wikipedia/conf/nagios && ./sync

download.wikimedia.org etc

• currently on zwinger

Test cases

Here are some test cases you can use to test the apache configuration after changing something.

GET /wiki/Foo HTTP/1.1
Host: en.wikipedia.org

GET /wiki/Foo HTTP/1.1
Host: www.wikipedia.org

GET / HTTP/1.1
Host: en2.wikipedia.org

GET /wiki/Main_Page HTTP/1.1
Host: www.wikipedia.com

GET / HTTP/1.1
Host: wikipedia.com

GET / HTTP/1.1
Host: wikibooks.org

GET / HTTP/1.1
Host: wikiquote.org

GET / HTTP/1.1
Host: dk.wikipedia.org

GET / HTTP/1.1
Host: foo.wikipedia.org

GET /wiki/Main_Page HTTP/1.1
Host: test.wikipedia.org

GET / HTTP/1.1
Host: webshop.wikipedia.org

GET / HTTP/1.1
Host: boards.wikimedia.org

GET /wiki/Foo HTTP/1.1
Host: en.wikipedia.org
User-Agent: Exalead

GET /wiki/Foo HTTP/1.1
Host: meta.wikimedia.org

GET / HTTP/1.1
Host: en.wiktionary.org