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Server configuration requirements

We're actively rewriting our user guide, so check back for improved coverage.

This page describes required web server configuration that you need in order to install Kayako Classic Download.

Server software requirements


PHP PHP 5.5 and PHP 5.6 are recommended and supported by Kayako Classic.
Kayako will work with PHP 5.4, but you might face performance issues or potential bugs.

NOTE: PHP 7 is not yet supported. (Kayako Classic uses some 3rd party libraries which require earlier versions of PHP. We're working to update them.)

MySQL server

As of Kayako Classic 4.72, MySQL version 5.6.31 is the minimum requirement.

Important: There is a known bug with some MySQL versions which causes upgrades to fail with the following error: Uncaught Exception Invalid SQL SELECT section. This bug has been fixed in the latest released MySQL versions 5.6.31 and 5.7.13. We recommend using the latest version of MySQL server to avoid any issues.

Web server

You can use any web server daemon – such as Apache, nginx, IIS – so long as it is fully compatible with the required PHP configuration (detailed below).

NOTE: If you're running Kayako Classic on a Linux server with SELinux, you'll need to configure it to permit Kayako Classic activities. If you're not familiar with SELinux, we recommend you disable it, as Kayako Classic will not function if it's configured incorrectly. 

Required settings


These settings are done in the PHP configuration file "php.ini" of the server on which you are installing the helpdesk.


If you have 'mod_security' installed on your apache web server, you must either disable it or whitelist your Kayako Classic files (so they are exempt from all 'mod_security' rules).


sql-mode : set to not strict. Refer to user guide here to know how to disable MySQL strict mode.

max_allowed_packet : should be 64M (Minimum)

connect_timeout : should be 300 (Minimum)

PHP caches and accelerators

Kayako Classic accesses many scripts spread across many files for each connection. If you do not have a PHP cache, unless your web server is very finely tuned you will find the application to be less responsiveness. 

We strongly recommend that your web server has a PHP cache like xcache, apc or eaccelerator installed. We find that xcache is the easiest to install and most readily available, and use it ourselves.

Required PHP modules

Most of these modules are included by default. However, we have compiled a list of those which are definitely required by Kayako Classic for good measure:

Server hardware requirements/configuration changes

It is very difficult to quantify server hardware requirements for running Kayako Classic. Our customers run their helpdesks on a mix of dedicated hardware, shared hardware, and virtualized environments with restricted resource access.

Whichever environment you choose, assuming your database server will be run from the same hardware, the minimum hardware requirements for a small scale Kayako deployment installing Kayako are:

  • 2 GB of RAM (allowing for operating system processes)
  • 20 GB of hard disk space available for your helpdesk (realistically, you should allow more than this for future growth)
  • Access to the equivalent of a 2 GHz CPU core

NOTE: For Linux operating system, SELinux must be disabled or set to permissive mode.

So, what's recommended?

What we use for Kayako Classic OnDemand

The web application element of Kayako Classic is platform independent, so the server requirements will remain the same for Windows as well as Unix/Linux servers. Which is best for you will depend on a variety of factors - including resources, expertise and what fits within your organization.

That said, we do have our own favorite configuration, which is in part used for our OnDemand platform:

What we use
Operating system
It is well supported, secure, fast and easily configurable.
Web server
nginx (with php-fpm)
nginx is lightning fast and much more lightweight than Apache and IIS.
PHP version
PHP 5.5
We use PHP version 5.5 for Kayako Classic OnDemand.
PHP cache/accelerator
We find xcache to be lightweight and does the job very well.

What our customers use

Our customers use a huge variety of platforms and configurations, including both Linux and Windows. This is what we have identified to be the most common web server setup:

What we use
Operating system
Linux (CentOS, Red Hat Linux, Debian, Ubuntu)
Linux is free, well supported, fast and secure. That's why it is the most popular Operating System amongst our customers and the world.
Web server
Apache (for Linux and Windows)
Apache is the world's most popular web server, and very easy to configure. It is prepackaged into most Linux distributions, making it the quickest web server to get started with.
PHP version
PHP 5.5
We recommend 5.5 as it is the latest tested version.
PHP cache/accelerator
Most likely based on our recommendation, and also because it is fairly simple to install.

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  1. Kelly O'Brien

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