After some time of operating you might notice some decrease in performance of your store, especially if you have a large product catalog or a huge number of customer orders. The possible reasons of slowing down are various and in most complicated cases additional investigation will be needed. But still, there are several tips that may help you to speed up your site. They're rather simple to follow, but do not hesitate to get in touch with us if you have any questions or need our assistance with them.

Move images from database to file system.

For each image you want to display, a separate connection has to be opened to your database. Even if it's only one image per page, doubling the connections to the database isn't fun to think about.

Each time you do <img src="image.php?imageid=345"> or something similar, that's a separate request to the server, with PHP going to receive that image from the database. Even if you do use scripting to grab images from a non-public branch of your file tree, just using file reading creates very, very little overhead, while hitting the database creates a lot. Just connecting to the database alone, without any queries, is something which already takes a significant amount of server time (more in the sense of processing cycles than actual time).

Storing your images in database tables is not recommended from the performance point of view. Our advice is to place images into the file system. It can easily be done by modifying a single setting in the control panel. At the administration zone, follow to the 'Images location' section, and choose 'File system' at the 'Store images in' drop-down list value.

After that modify original .htaccess file (in /files directory) and change the code to:

<FilesMatch "\.(gif|jpe?g|png|GIF|JPE?G|PNG|)$">

Allow from all
</FilesMatch>
Deny from all

Toggle off tracking statistics

Tracking your visitors' movements is a very useful marketing feature, but it takes significant resources and may slow down the performance of your site. If there's not much need in such service, it can easily be disabled.

For v3.4.x:

in the customer/auth.php file, make the line

  include "../include/atracking.php";

as follows:

  #include "../include/atracking.php";

For v3.5.x and higher:

statistics are disabled via admin zone, 'General settings': uncheck 'Enable tracking statistics gathering' field.

Then clean statistic tables in the admin back-end of X-Cart: 'Summary page' -> 'Statistics clearing'.

Optimize database tables

An optimized table structure differs from a well-designed table. Table structure optimization has to do with reclaiming unused space after deletions and basically cleaning up the table after structural modifications have been made. The OPTIMIZE SQL command takes care of this, using the following syntax:

OPTIMIZE TABLE <table_name>;

where you should replace <table_name> with the name of the necessary table. Execute the above SQL query for each X-Cart table. You will find the list of X-Cart tables using the next SQL query:

SHOW TABLES;

Optimization should be used if you have deleted a large part of a table or if you have made many changes to a table with variable-length rows (tables that have VARCHAR, BLOB, or TEXT columns). Deleted records are maintained in a linked list and subsequent INSERT operations reuse old record positions. You can use optimization to reclaim the unused space and to defragment the data file.

Be aware that the table is locked while it is optimized, so if your table is large, you'd rather optimize it during a scheduled downtime or when little traffic is flowing to your system.

Install Zend Optimizer (optional)

The Zend Optimizer is a free application that runs the files encoded by the Zend Encoder and Zend SafeGuard Suite, while enhancing the running speed of PHP applications. Many scripts require that you have Zend Optimizer installed so you are able to run them on your server while decrypting and running them on-the-fly while increasing runtime performance.

Install additional Apache modules (optional)

The idea behind GZIP-encoding documents is very straightforward. Take a file that is to be transmitted to a Web client, and send a compressed version of the data, rather than the raw file. Depending on the size of the file, the compressed version can run anywhere from 50% to 20% of the original file size.

In Apache, this can be achieved using Content Negotiation, which requires that two separate sets of HTML files be generated: one for clients who can handle GZIP-encoding, and one for those who can't. This solution sends gzip-encoded files to clients who understand them, but does not allow for the compression of dynamically-generated pages.

A more graceful solution is the use of mod_gzip, one of the many additional modules available for Apache. We consider it one of the overlooked gems for designing a high-performance Web server. Using this module, configured file types will be compressed using GZIP-encoding after they've been processed by all of Apache's other modules, and before they're sent to the client. The compressed data that's generated reduces the number of bytes transferred to the client, without any loss in the structure or content of the original, uncompressed document.

You may ask your hosting administrators to install the necessary compression module: mod_deflate (Apache 2.0.x) or mod_gzip (Apache 1.3.x).

Custom optimization service

If this doesn't work, there's one more variant: to order our optimization service. It requires special investigation to find out the exact reason. Developers will inspect the store carefully, determine the reason of the site's slow performance and provide you with possible solutions. If you are interested, post the request to the message board.