What is CloudLinux?
Linux is the operating system of choice for most web hosting servers, for a number of reasons. Its user permissions model makes it typically more secure than Windows, it can run continuously without reboot indefinitely without slowing down or “leaking” memory, and it supports virtualization better than any other option.
But are all Linux distributions created equal? No. Certain distributions are designed with specific goals in mind. Ubuntu, for example, is geared toward desktop users, while Red Hat is a built for large-scale Enterprise use. A relatively new distro, CloudLinux, has recently been risen up to meet the specific needs of web hosting companies that offer shared and VPS hosting plans.
CloudLinux is a commercially developed Linux distribution intended to make shared web hosting easier, more secure, and more profitable. It has a number of features specifically added to deal with common issues of shared hosting management.
Major Features and Modules of CloudLinux
Lightweight Virtualized Environment (LVE) Limits
With CloudLinux, the hosting administrator can setup specific per-customer limits over CPU, IO, Memory, Number of Processes, and Concurrent Сonnections. This can help with two different use cases:
- Setting up different hosting packages for different customers at different price points, which can all be served from the same OS on a single (real or virtual) server.
- Easily throttle abusers and bad actors without causing problems for other customers sharing the server.
The vast majority of shared hosting plans make us MySQL databases to run apps like WordPress, Drupal, Joomla, and Magento.
With the MySQL Governor module, CloudLinux provides a set of utilities to monitor and operate MySQL usage in a shared hosting environment. Each MySQL thread is individually monitored to generate usage statistics on CPU and I/O in real time. This allows hosting admins to instantly detect abuse, or simply poor query writing, and respond appropriately with throttling, user messaging, or other actions.
The CageFS file system works on a per-user basis to individually encapsulate each hosting customer. This prevents you customer users from seeing other users or their sensitive data.
CageFS also provides security against most forms of privilege escalation and information disclosure attacks.
None of these enhancements are visible to customers — they are protected without having to worry about security settings or change how their scripts normally handle file permissions.
SecureLinks works at the kernal-level to increase security by to prevent all known forms of symbolic link attacks.
PHP Selector works with CageFS to allow each hosting customer to select their own specific version of PHP, as well as which modules and versions will be used with PHP. This gives customers more flexibility and control over their hosting environment.
CloudLinux also speeds up the process of updating PHP, which leads to higher security and less maintenance-related downtime.
Similar tools for other languages allow customers to choose their own version of Ruby and Python.
Most shared hosting customers use one of a handful of popular applications — WordPress, Joomla, Drupal, Magento. If many customer on a single server are using (for example) WordPress, a huge number of frequently read files (WordPress core) are duplicated over and over.
Conventionally, these duplicate files are treated as separate entities by caching engines, leading to a lot of redundant I/O.
Optimum cache recognizes when files from different users are actually exact duplicates and caches them as a single resource, improving I/O performance by 20% to 30%.
Mod_lsapi is a drop-in replacement for other Apache PHO modules such as SuPHP, FCGID, RUID2, and ITK. It is the fastest and most reliable way to serve PHP pages from Apache, has a low memory footprint, and understand PHP directives from
Major Benefits to CloudLinux
Per tenant usage controls and throttling, along with in-depth MySQL monitoring in real time, help prevent usage spikes and abuse, leading to a more stable and predictable hosting environment.
Traditionally, shared hosting servers needed to keep a lot of “wiggle room” open in order to maintain stability in the case of sudden usage spikes. It is common to only use 20% to 30% of server resources at any given time.
Being able to lower usage demands through Optimum Cache, and better predict and control demand through the LVE Manager allows hosting admins to increase density dramatically, with normal usage rates up to 80% of capacity.
The CageFS and Secure Links modules work together to prevent the majority of both direct attacks and inadvertent security breaches.
CloudLinux can potentially increase shared hosting provider profitability in a number of ways:
- Increasing density lowers server costs.
- Detailed usage reports from LVE and MySQL Governor make it easier to upsell high-use customers to more appropriate VPS plans. This increases their value as customers, and also allows for higher customer density on shared servers.
- Fewer security threats lowers support costs.
Here's What Your CloudLinux Hosting Needs To Offer
CloudLinux is a Linux distribution that was created especially for use as a web server. As a result, it is widely used in the hosting industry. Not all host tell you which Linux distribution(s) they use. So if you are interested in a hosting company that doesn't say, you need to ask if you want to run on CloudLinux. We recommend A2 Hosting for CloudLinux.