Following our earlier entry about installing Magento
Enterprise, we thought it would be appropriate to follow up with some
tips for getting more from your Magento installation. One of the major
criticisms leveled at Magento is its speed; many complain that it is far
too slow. In this article we'll go through some steps you can perform
to fine-tune your server to allow Magento to run more smoothly and more
quickly in a production environment. Our examples are geared at a
Debian-based LAMP stack, but most can be adapted for other platforms.
Check out our tips on:
Memcached
Memcached
is a distributed memory caching system that stores data retrieved from
the database (or other data source) in memory, allowing repeat reads to
retrieve the data from memory rather than needing to query the database
again, greatly increasing the speed of web applications.
The first thing to do is install the memcache daemon and client libraries:
root# apt-get update
root# apt-get install memcached php5-memcache
|
To check if memcache is running, you can use the following command:
root# ps -ef | grep memcached
|
You should ensure that the localhost has been added to the configuration, this can be done using grep as shown here:
root# grep 127.0.0.1 /etc/memcached.conf
|
This should output
-l 127.0.0.1 if localhost is included in the configuration. If not, add this line to the configuration and restart memcached:
root# echo '-l 127.0.0.1' >> /etc/memcached.conf
root# /etc/init.d/memcached restart
root# /etc/init.d/apache2 restart
|
You need to create a PHP configuration file to include the module, which on a Debian-based system should be in
/etc/php5/conf.d/memcache.ini:
Magento itself can also be configured to utilise some memcache
optimisations built into the software. The following XML should be added
to the
/var/www/app/etc/local.xml file once it has been generated:
>
...
>
><![CDATA[memcached]]>>
><![CDATA[database]]>>
>
>
>
><![CDATA[127.0.0.1]]>>
><![CDATA[11211]]>>
><![CDATA[1]]>>
><![CDATA[1]]>>
><![CDATA[10]]>>
><![CDATA[10]]>>
><![CDATA[1]]>>
>
>
><![CDATA[0]]>>
><![CDATA[]]>>
><![CDATA[]]>>
><![CDATA[]]>>
><![CDATA[]]>>
>
>
>
...
>
Apache mod_cache
The
Apache mod_cache module
allows Apache to cache content on disk or in memory, thus decreasing
page load times. Caching for dynamic sites such as ecommerce needs to be
approached with some caution; the cache may become invalid and thus
customers may receive stale content. To enable mod_cache perform the
following steps:
root# a2enmod cache
root# a2enmod disk_cache
root# a2enmod mem_cache
|
Enable disk caching in the disk_cache.conf configuration file by uncommenting the
CacheEnable line in
/etc/apache2/mods-available/disk_cache.conf. Make sure you remember to restart apache after doing this.
There is also a utility you can install which will clear the disk
cache, the following code sample shows how to install and run it:
root# apt-get install apache2-utils
root# htcacheclean -d30 -n -t -p /var/cache/apache2/mod_disk_cache -l 100M -i
|
This will clean our cache directory every 30 minutes and make sure
that it will not get bigger than 100MB. You can tune these settings to
fit your particular site needs.
Apache mod_expires
Well-written browser software will keep a cache of the webpages a
user visits. Each webpage should have a content expiry header directive
that tells the browser when the cache expires. If this header is not
correctly set then the browser will re-request the content from source
with every page hit. In order to ensure that the Magento pages have the
correct content expiry in the header, you can add the following block to
Magento's
.htaccess file:
<ifmodule mod_expires.c>
ExpiresActive On
ExpiresDefault "access plus 1 month"
</ifmodule>
|
Apache KeepAlive
The
Apache KeepAlive
functionality allows the TCP connection between a client and the server
to remain open, allowing multiple requests to be served over the same
connection. This can decrease page load times particularly on webpages
with lots of images since it removes the overhead of having multiple
connections opened. To use this functionality, edit the
/etc/apache2/apache2.conf, find the KeepAlive entries, and make sure
they are enabled as follows:
KeepAlive On
KeepAliveTimeout 2
|
This will enable the KeepAlive feature; the timeout parameter is in units of seconds.
PHP APC
PHP APC is an Alternative PHP Cache that caches the byte-compiled PHP
code, which means that repeat requests to the same PHP script should
not need to be recompiled before being served, which will increase
performance. This is a pear module, but also has some system
dependencies, so to install it we run the following:
root# apt-get install apache2-threaded-dev php5-dev php-pear make gpp
root# pecl install apc
|
The APC configuration file should be created, and on the debian system the path would be
/etc/php5/conf.d/apc.ini. We place the following lines into this file:
extension=apc.so
apc.shm_size=256
apc.num_files_hint=10000
apc.user_entries_hint=10000
apc.max_file_size=5M
|
Also make sure that Magento is using APC for caching by editing
/var/www/app/etc/local.xml and add the following somewhere inside the
tags:
>
…
>
>apc
>
>alphanumeric
>
>
….
>
...
>
To verify if APC is installed, we can check if the output of phpinfo
includes reference to it, by running the following command from the CLI:
root# php -r 'phpinfo();' | grep 'apc'
|
Database Session Storage
Typically, database servers are less utilised than web servers.
Performance can usually be improved by moving session handling from the
web server filesystem into the database server. Magento asks you whether
you prefer a file or database session save type, but this is very easy
to change in the XML. Open up
/var/www/app/etc/local.xml, locate the
tags, and change the value so it looks like this (the default is <![CDATA[files]]>):
<![CDATA[db]]>>
Another alternative is to use memcache for storing the sessions -
this isn’t as persistent as the database store, but may be faster:
<![CDATA[memcache]]>>
You can add details of your memcache server in the session save path:
<![CDATA[tcp://127.0.0.1:11211?persistent=1&weight;=2&timeout;=10&retry;_interval=10]]>>
GZip Compression
Web pages can be compressed using
GZip
between the server and the client, reducing the amount of data that
needs to be transferred. Although the act of compressing and
decompressing adds a performance overhead there is usually a net gain in
reducing the amount of traffic especially for large pages. To use GZip
compression, enable the
mod_deflate module in Apache, and add the following to the vhost for the site:
<ifmodule mod_deflate.c>
SetOutputFilter DEFLATE
# Netscape 4.x has some problems...
BrowserMatch ^Mozilla/4 gzip-only-text/html
# Netscape 4.06-4.08 have some more problems
BrowserMatch ^Mozilla/4.0[678] no-gzip
# MSIE masquerades as Netscape, but it is fine
BrowserMatch bMSIE !no-gzip !gzip-only-text/html
# Don't compress images
SetEnvIfNoCase Request_URI .(?:gif|jpe?g|png)$ no-gzip dont-vary
# Make sure proxies don't deliver the wrong content
Header append Vary User-Agent env=!dont-vary
</ifmodule>
|
MySQLTuner
A final tool to consider for performance improvement is
MySQLTuner.
MySQLTuner is a Perl script which analyses your database and gives
recommendations which variables you should adjust in my.cnf to increase
performance. This can really help to get the database, often a
performance bottleneck for these types of applications, performing as
well as possible without needing expensive hardware upgrades. To
install and run this utility, simply do:
bash$ wget http://mysqltuner.com/mysqltuner.pl
bash$ perl mysqltuner.pl
|
You see some recommendations for which variables could be changed to
improve performance, it is best to make changes incrementally and one at
a time so you can see how they affect the performance of the database
Bonus Security Tip: Changing the Admin URL
Although not an actual performance issue, you can improve security by
changing the default URL from 'admin' to something more obscure, such
as '5i8FNvHg'. This will decrease the probability that a malicious user
will hit upon your admin log-in page by guessing that the admin site is
located at yourdomain.com/admin/, or that automated scripts scanning for
Magento admin pages will find it.
To change the admin address you first need to stop Apache and clear the cache:
root# /etc/init.d/apache2 stop
root# rm -rf /var/www/var/cache/*
root# rm -rf /var/www/var/session/*
|
Then open up the
/var/www/app/etc/local.xml file, locate the
tag, and change the 'admin' part it to something a lot more random, eg:
<![CDATA[gJpf2VK5]]>>
Then set Apache running again (bearing in mind your site will be down for the duration of this operation!):
root# /etc/init.d/apache2 start
|
More Tips?
This was a selection of the tips we use to keep our Magento sites
running smoothly; but is there anything we missed? If you have comments
or tips for other users, please leave us a comment and let us know!
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