Installing PHP APC on GNU/Linux Centos 5

原贴：http://2bits.com/articles/installing-php-apc-gnulinux-centos-5.html

Published Mon, 2008/03/24 - 13:49, Updated Wed, 2009/07/15 - 23:40

Complex PHP applications, such as Drupal, can gain a lot of performance benefits from running a PHP op-code cache/accelerators .

APC,
Alternate PHP Cache, is now the most maintained free/open source op-code cache, and is being used more and more as it emerges to be the
most stable.

The instructions here detail how to get APC running on a CentOS 5 server. The server happened to have Plesk on it as well, which initially made me hesitant to install APC "normally", since Plesk is so picky on what other software is installed on the server. However, it seems to have worked out well.

First, we need the pecl command so we can download and install APC from the repositories.

Do to so, we execute the following command:

yum install php-pear

But, this will not run on its own, we need the following package for the phpize command:

yum install php-devel

We also need the apxs command, which is installed via the following package:

yum install httpd-devel

Now we have all the software we need, so we install apc via the pecl command:

pecl install apc

Once that finishes, we need to enable apc in Apache's configuration. the following command should do this for us.

echo "extension=apc.so" > /etc/php.d/apc.ini

Then we restart Apache:

/etc/init.d/httpd start

And we are all done. Watch for less execution time per page, and decreased memory usage per Apache process compared to what you had
before.

Links

You can find some additional tips at Setting up Alternative PHP Caching APC support on Centos server .

Add new comment

Pecl may not be able to perform the installation

Submitted by Joe (not verified) on Fri, 2008/11/21 - 00:05.

Due to pecl following an 8 MB restriction that disregards php.ini, pecl may bomb out with a fatal error if you attempt to install apc with it. You can solve this by using the command 'pear install pecl/acp' instead.

Got this working on Ubuntu 7.04 Feisty

Submitted by Volomike (not verified) on Sat, 2008/06/14 - 03:53.

I already had PEAR/PECL installed on a system with Apache2 and PHP5, running under Ubuntu 7.04 Feisty.

$ sudo su # apt-get update # apt-get install php5-dev # apt-get install apache2-prefork-dev # apt-get install apache-dev # pecl install apc

answer yes when prompted

# echo "extension=apc.so" >> /etc/php5/apache2/php.ini # /etc/init.d/apache2 stop # apt-get remove apache2 # apt-get install apache2 # /etc/init.d/apache2 stop # /etc/init.d/apache2 start # exit $

At least I hope this is working. I wish I knew how to test if the performance actually increased.

Trouble

Submitted by Sebastian Wikholm (not verified) on Thu, 2008/06/05 - 07:42.

The installing with your instructions goes just fine, but APC doesnt want to start for me. Apache / PHP gives the following error:

PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php/modules/apc.so' - /usr/lib/php/modules/apc.so: cannot open shared object file: Permission denied in Unknown on line 0

Any help would really be appreciated

Thanks, Khalid. I asked my

Submitted by venkat-rk (not verified) on Tue, 2008/03/25 - 09:57.

Thanks, Khalid.

I asked my host to do it for me and immediately from then onwards, all my drupal pages are showing an internal 500 server error.

Does APC have a problem with php running as suphp (like suexec)?

Thanks,
Venkat

Doesn't work

Submitted by Khalid on Tue, 2008/03/25 - 10:44.

Actually I recall reading specifically that suexec is known not to work with APC. Perhaps this is because it is CGI (new process every time a request comes in). The only versions that work with APC and other accelerators are the mod_php (Apache) or Fast CGI.

In your case, suexec is a trade off (security vs. performance).
--
2bits -- Drupal consulting

well, it seems to work:-) My

Submitted by venkat-rk (not verified) on Tue, 2008/03/25 - 10:55.

well, it seems to work:-)

My host had simply given incorrect permissions on the temporary APC script. I don't know the intricacies of it, but they said setup would be slightly different on a cPanel VPS and enabled it.

Venkat

suphp

Submitted by Khalid on Tue, 2008/03/25 - 11:20.

Thanks for the email.

Your site is running suphp (which is still CGI), and suhosin which some say is incompatible with op-code caches (not sure).

Please try with and without APC using devel and see if the pages execute faster with APC on suphp. I doubt they would.
--
2bits -- Drupal consulting

suggestion

Submitted by Drupal Theme Garden (not verified) on Tue, 2008/03/25 - 05:24.

Nice and simple tutorial.

One question:
Why APC, and not eAccelerator?
In some of your previous articles (benchmarking APC vs eAccelerator using drupal and PHP op code caches/accelerators: a must for a large site ) you wrote that eAccelerator has better performance over APC.

Stability

Submitted by Khalid on Tue, 2008/03/25 - 10:50.

eAccelerator is definitely better than APC for speed (faster) and memory utilization (uses less memory).

However, with newer versions of PHP and Drupal, APC now has the edge in stability. Previously, we had maybe one or two seg faults with eAccelerator per week, which was acceptable, and the logwatcher script restarted things automatically.

After upgrading, it was seg faulting every 2 hours. Once we switched to APC, it was stable and rock solid.

There is also xcache, which we experimented with, but not used in production work.

I plan to publish updated benchmarks of APC, eAccelerator and xcache in the near future.
--
2bits -- Drupal consulting