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Dedicated Server with a Large Site

A dedicated server has different challenges than a shared hosting server. With shared hosting, usually you wish to give high performance without allowing a single user to monopolize server resources. However, on a dedicated server with a relatively large site, you want to maximize the performance without limiting the usage. Most of the default LiteSpeed WebAdmin Console settings are suitable for both scenarios, but there are a few exceptions. Here are some settings that you can adjust to push the maximum capacity.

Enable Caching

Caching is the key to improving site performance. It is fundamental. If possible, you should always enable caching. If there is an LSCache plugin available for your application, use it. If a plugin is not available, you may also consider configuring LSCache through rewrite rules. Be sure to test for a cache hit before undertaking any benchmark testing.

Increase Maximum Connections

With caching enabled to avoid PHP and MySQL processes, the site will undoubtedly be faster. However, there will still sometimes be uncached pages, such as shopping cart checkout pages, or other pages that have expired in cache. For this content, the performance of the application is at the mercy of PHP performance. The PHP SuEXEC Max CONN setting controls how many concurrent PHP processes are allowed. The default of 10 may not be enough for a dedicated server. How high you increase it depends on the size of the server, especially in terms of RAM and CPU. While you could technically set it as high as 1000, higher is not necessarily better. An 8-core physical server, for example, will likely not benefit from any more than fifty to eighty processes.

Avoid Forking PHP Worker Processes

With shared hosting, LiteSpeed Web Server dynamically forks PHP worker processes in order to save server resources. The server spawns new worker groups or forks a child PHP worker process as necessary to serve incoming requests. While this preserves server resources, it penalizes performance by slowing down PHP’s initial start-up response time. This trade-off makes sense for shared hosting, but you may not wish it on a dedicated server. Set the LSAPI_AVOID_FORK environment variable to 1 in order to keep the PHP worker process alive for a longer period of time. Doing so ensures that there will always be a PHP worker available to serve incoming requests, and no delay in PHP response time.

Tip

You can set the environment variable within WebAdmin Console in the PHP tab, Environment Variables field.

Increase PHP Running Time

The purpose of Max Idle Time is to specify the number of seconds before an external application is stopped by the server. To make PHP live longer, simply increase Max Idle Time to a large number, such as 86400, in the PHP tab, or at the External App level.

Move PHP Session Data

If the server has enough free memory, you can move PHP sessions and opcode cache disk storage to /dev/shm.

Check PHP Info

Take a look at your phpinfo.php page, and check these few modules:

timezonedb

It’s recommended to have the timezonedb module enabled for PHP. You may not notice the absence of timezonedb on your dedicated server, but enabling it can keep PHP from needing to scan hundreds of directories.

xdebug

Make sure the PHP xdebugmodule is disabled if you don't need it. xdebug is for developer IDE integration only and should not be installed by default.

snmp

Same for snmp. The snmp module will scan and parse available MIB files, but not everyone needs snmp support.


Last update: July 12, 2021