Couple of years ago, AdriaHost introduced the CloudLinux operative system (OS) on all servers, which enables us to give our users a guaranteed amount of resources on shared hosting and also to isolate the issues at the user’s account level.

What is CloudLinux?

CloudLinux is a commercially supported Linux OS. It includes technology at kernel level, titled LVE, that enables you to take control of processor and memory per user as well as making a great basis for virtualization of a shared hosting. CloudLinux delivers advanced resource management, a better safety and a sleek performance. These performance improvements are a great helping hand for us in offering a better hosting solution to our clients and generate higher stability.

How Does CloudLinux Assist Us In Managing Server Resources?

Hosting accounts that make excessive use of resources will be temporarily deactivated, which reduces negative effect of this over-consumption of resources with other users. This is accomplished through rate limiting, meaning that the website which nears the allowed limit (soft limit) will experience deceleration, and in moments when the limit is breached (hard limit), the website will display a 5xx page. When the overall amount of processes (Apache/HTTP executions) reaches the allowed limit, website visitors will also see a 503 Over Quota error message, implying that the hosting account exceeded its allowed resources.

When hosting account’s resource limits are again within the allowed bounds, the website will proceed with normal functioning. Most resource issues are due to hacked or abused website, so in this way, AdriaHost is preventing innocent websites to suffer because of one site’s problems.

Will This Cause Limitations on Regular Websites?

It is possible that, once hacked or non-optimized, a website may reach aforementioned limits. If you see the “503 Over Quota” error message on your website, we strongly advise that you contact AdriaHost immediately through support ticket, so that we can check in real time whether your website has been hacked, it’s under attack or is simply not optimized and in need of a better hosting solution.

How Do I Check My Website’s Resource Usage?

The resource usage on your website can be easily monitored in your cPanel. After logging into your cPanel, under Logs, you will see an icon called Resource Usage. By clicking this icon, you will get a full insight into the resources used by your website.

You will see information on what limits your website reaches most frequently, as well the amount of times the visitors were served a 503 error message due to excessive usage of resources. If you are shown the photo as displayed above, your account has most probably been hacked or non-optimized so you should look into this. AdriaHost is there to help you in this process, contact our support and we will provide you with advice and insight. Optimization and updating the scripts are all under your jurisdiction.

Clicking on details, you can get a full overview of resource usage on your hosting account.

OK, So What Are All These Numbers?

Once you’ve opened a detailed overview of resources, you will see graphs of usage per time, as well a table with exact quotes on how much resources you used in a certain moment in time. You may choose multiple types of graph displays depending on time: the last 10 minutes, the last 30 minutes, the last day, the last week and so on. The best kind of display is given in daily graphs, where you can have correct insight into the parts of the day when your website is most active.

Below is a summary of a graph:

The graph will show your account’s CPU, the memory usage and overall processes. CPU is calculated based on the limits assigned to your hosting account. Therefore, if your account has a 25% limit of total CPU resources, and it uses 5% of total CPU resources – the graph will show that account uses 20%. This shows how much resources your website is using in real time, as well as time interval you have chosen.

If your account has occasional spikes in usage resources, this is no problem, because your account was assigned with more resources for periods of highest usage – however, in case your account reaches shared hostings limits in every moment, then you will see a 508 error message and then you may want to consider optimizing your scripts and moving to a VPS or Dedicated server.

Also, if you are currently on a standard shared hosting plan and have a large number of websites on your account, you can solve the issue by placing your websites on multiple smaller accounts. CloudLinux measures resources per account, not per domain, so having a large number of domains on a single account means they all add up to overall resource usage.

We can therefore see that the most frequent cause of excessive resources usage is a bad code, most likely in 3rd party scripts like plugins or WordPress themes. If there is a WordPress on your account that causes this excessive resource usage, we recommend deactivating all the addons and then monitor the resource usage. After that, you may go back to activating your addons one by one, so that you can find you which plugin causes the issue. More information on optimizing your WordPress websites can be found in our Knowledge Base.

Also, you could check your website’s /public_html folder and locate the error_log file within the folder. Take a look at logs in error_log file and remove all the errors listed in it. Optimization of database tables through phpMyAdmin tool is also a fine way of optimizing your website.

If you have a well optimized, well coded website with no errors, it will greatly reduce the resource usage on your website and it will work faster and more stable.