CloudLinux OS

CloudLinux OS

Your shared hosting server is going down because of a sudden increased in server load is a thing of the past, thanks to the CloudLinux OS.

It is the first commercial Operating System that is basically designed for shared hosting environment, which is the choice of web hosting providers because it meets their specific needs and demand of the stable environment in extreme situations. It provides a stable hosting environment in which all shared hosting accounts are isolated from each other and will not be effected by bad neighbor account. Each shared hosting account is assigned a definite resource limit which will prevent sudden load from taking the server down. Better stability decreases support costs by limiting support calls and tracking down of resource abuse. With Cloud Linux your server becomes more efficient which means that you can add more hosting accounts on it to get the most out of its resources. It works with all control panels and is compatible with most software that used with RHEL or CentOS.

How it works:

Traditionally in the event of sudden load or spike by large amount of traffic, bad script or DDOs attack to specific tenant’s website on traditional shared hosting server, It will not have any control over it and in result all other tenant’s website are slowed and brought down.

But each tenant on Cloud Linux hosting server is isolated by their own individual Light Weight Virtualized Environments called LVE in short. LVE is a kernel level technology which ensures that a predetermined amount of resources is given to each tenant. If any tenant gets a huge amount of traffic then the load will be restricted to his LVE and only his website will be impacted. It will not effect other tenants on that shared server and in result server is always up and stable.

LVE is lightweight, transparent and has roots with container based virtualization. Its goal is to make sure that no single website can use all resources of server and bring it down.

It was made possible via collaboration of kernel and Apache module.

Apache Module: mod_hostinglimits

LVE detects the Virtualhost through which request came from and check if it is for PHP or CGI script. Then it will switch the request(used to serve by Apache) into LVE(for the user) by determining the user from SuexecUserGroup(of that Virtual host entry) in Apache config file. Then it lets Apache to serve the request and remove the process from LVE after its done.

Each tenant Light Weight Environment limits the amount of Apace processes(entering into LVE) to prevent single website using all Apache processes on shared hosting server. Ones the limit is reached for individual tenant, Apache module (mod_hostinglimits) will not be able to put an Apache process into LVE and in result the website will return 503 Error code (This error code is selected because it would not interfere with other error codes). In this way heavy content website will slow down and return 503 error without affecting other tenants.

For more information about Cloud Linux, Please visit their official website: