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So some of our firewall’s have a default policy of dropping any packets which are not allowed for. This causes a problem when you flush the whole firewall, as now you have zero allow rules and a default policy of drop. That’s right, it means you’ve just locked yourself out of the server!

I always forget how to flush a firewall safely with defualt policy of drop. I know you have to set it to accept, put always forget that the switch is -P. The below will work for setting the default policy of the three main chains and flushing the firewall:

/sbin/iptables -P INPUT ACCEPT /sbin/iptables -P OUTPUT ACCEPT /sbin/iptables -P FORWARD ACCEPT /sbin/iptables -F

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Installing APC for your php webserver

by admin on Nov.17, 2010, under Uncategorized

APC also known as Alternative PhP Cache is an easy way to speed up and optimize performance on your webserver. We recently installed it on a server that was spiking to 40.00-80.00 load and have seen the server serve files quicker and only spike to a 2.00 – 4.00 load during peak times. This server was sending out an application on the Zend Framework which is notoriously heavy – so it was good to get such a big speed and optimization boost.

How does apc work? Well for those of you not familiar, everytime a php program is called, a text file is compiled into c code and then executed by the server. On desktop apps, and other programming languages usually this code is pre-compiled and ran everytime. (Think about an EXE file – there is no way to see the lines of code that make up the file.) Well what if we saved this compiled code and skipped the whole step of compiling it every single time a user request the same page. Well apc does this!

To install APC on a redhat/centos based machine is super easy:
yum install php-pear yum install php-devel yum install httpd-devel yum install apr-devel.x86_64


pecl install apc
#Then check /etc/php.d/apc.ini and put:

extension=apc.so

; Options for the apc module

apc.enabled=1

apc.shm_segments=1

apc.optimization=0

apc.shm_size=32

apc.ttl=7200

apc.user_ttl=7200

apc.num_files_hint=1024

apc.mmap_file_mask=/tmp/apc.XXXXXX

apc.enable_cli=1

apc.cache_by_default=1

apc.filters = "(kses\.php)|(wp-cache-.*\.html)"
#restart apache

/etc/rc.d/init.d/httpd restart

#check /etc/php.d/apc.ini

After that you can even do a `locate apc.php` and move this file into a web servable directory and you will see charts that will show you all kinds of neat statistics about its performance.

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Does Cufon affect SEO and how? YES, it does!@

by admin on Nov.16, 2010, under Uncategorized

I hear you now - I’m SOOOO wrong on this, right? Cufon is a standard compliant javascript file with failback support – It MUSN’T affect SEO at all! The previous means - that even in browsers (or robots) that do not support cufon, the text will be seen just as text – index-able plain text! This text will get weighted and indexed just like any other text on the internet. So I’m an idiot and wrong – right? Not exactly.

So then how does cufon affect SEO? Well now that google has released “instant preview”, cufon font is not being rendered in the images. Some suggest it is a problem with google’s bot. Regardless, this is an issue for YOUR cufon website! Your image can come up completely incomplete in the preview pane.

I will use Katy Perry’s website as an example. Just look below at the highlighted sections that use Cufon and see how cufon is missing completely:

I’m currently working on a fix for this and testing out a few different options. I will update you once I verify it.