admin how-to

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* now try browsing to http://microformats.org/ and make sure it loads
* now try browsing to http://microformats.org/ and make sure it loads
* report back on IRC or Twitter to whoever pointed out that the server was down.
* report back on IRC or Twitter to whoever pointed out that the server was down.
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=== semaphore exhaustion ===
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This is a much rarer error state: Apache error log stating: <code>[emerg] (28)No space left on device: Couldn't create accept lock (/etc/httpd/run/accept.lock.NNNN) (5)</code>. Thanks to http://rackerhacker.com/2007/08/24/apache-no-space-left-on-device-couldnt-create-accept-lock/ for the hint.
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* If the output of <code>sudo ipcs -s</code> is lots of lines of dead apache process IDs leaving semaphores behind:
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** <code>sudo sh</code>
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** <code>for i in `ipcs -s | awk '{print $2}'`; do (ipcrm -s $i); done</code>
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* you will see two lines of erroneous output:
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** <code>ipcrm: invalid id (Semaphore)</code>
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** <code>ipcrm: invalid id (semid)</code>
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… and then proceed to restart as before.
== server transition testing ==
== server transition testing ==

Revision as of 19:08, 6 February 2012


This is a reference for various tasks that admins may have to perform.

Contents

web server restart

If you're reading this then either the server is up, or the server is down and you're reading a Google Cache copy (thus it's still useful to post this here).

If the web server is down, e.g. someone notes on IRC or Twitter:

Then:

semaphore exhaustion

This is a much rarer error state: Apache error log stating: [emerg] (28)No space left on device: Couldn't create accept lock (/etc/httpd/run/accept.lock.NNNN) (5). Thanks to http://rackerhacker.com/2007/08/24/apache-no-space-left-on-device-couldnt-create-accept-lock/ for the hint.

… and then proceed to restart as before.

server transition testing

Some things to check when transitioning to / setting up a new server.

editing your local hosts file

In order to test a new server from your local machine and still have hardcoded URL references work, you may need to manually edit your local machine's hosts file, per:

http://www.howtogeek.com/howto/27350/beginner-geek-how-to-edit-your-hosts-file/

Your browser should now behave *exactly* as if you'd switched actual DNS.

This makes it a very good way to test.

DNS flush cache tips

If you're using OSX, you'll probably have to run this to flush the local dns cache:

dscacheutil -flushcache

current servers being tested

home and blog

wiki

irc bots

profiles

media

mailing list archives

shorteners

other

attack logs

Note any logs / summaries of attacks. Anything more than a summary should be moved to its own page.

see also

admin how-to was last modified: Wednesday, December 31st, 1969

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