CPU load and RAM usage are the two most important measurements in your server monitoring tool, the Box status. These measurements show you whether your site is overloaded and can help you analyze errors and problems.
How to work with the graphs
Depending on what information you want to see, you can filter and customize both graphs. The two graphs are structured in exactly the same way:
The graphs show measurements from the last 24 hours.
The measured points are one minute apart and are average values.
You can take a closer look at a particular period by dragging a frame around it on the graph. This will zoom in on the selected period of time.
For clarity, 12 AM is marked with a vertical gray line.
Two colored (orange and red) horizontal markings serve as reading aids. The presence of these lines does not mean your site is overloaded.
If you click on the arrow symbol in the upper right corner and then on the graph, you can hold down the left mouse button and drag the view left or right.
CPU usage
The number of vCores on your Box depends on the purchased hosting plan. For example, a Starter Box has one vCore and a Pro XL Box has four.
The y-axis (the vertical axis) shows the CPU load in percent. The x-axis (the horizontal axis) shows the course of time.
The orange line marks the 100% and the orange line the 200% load threshold for any given time. As mentioned above, these lines purely serve as reading aids. They do not mean your Box was overloaded at any point. The blue graph represents the actual CPU load of your Box.
How do I read the CPU graph properly?
The CPU load describes the utilization of the virtual processor cores of your Box in percent. A high CPU load indicates that your Box needs to render many complex processes, and a low CPU means that your Box needs to handle fewer rendering processes. The percent is the result of all the processes having to be computed by the CPU at any given time.
If your Box’s CPU load is too high for a prolonged period, your website may not function properly. A 504 Gateway Timeout is the most common error when this happens.
Your Box's CPU can easily spike to well over 100%. This is not necessarily a sign that an error has occurred on your Box, but it does indicate that an extremely high computing load was generated by an event on your Box.
If you want to check the exact CPU load at a certain time, simply hover over the time on the graph. As soon as the cursor is inside the graph area, lines appear parallel to both axes giving you the exact values, i.e. time and CPU, of the respective point.
Why is my CPU load high?
There are many reasons why your CPU graph might be showing a high load. Generally speaking, a high CPU load does not indicate that your site is inaccessible or that it is not working properly. It only means that your CPU has had to work extra hard at certain times. Cronjobs or high traffic to your site can cause a high CPU load, for example.
CPU: What is a CPU overload?
If you see isolated load peaks on the graph, it does not mean your CPU was overloaded. Only a constant load of well over 100% over a longer period of time indicates a CPU overload.
CPU: What is a high CPU load?
We talk about high CPU load when the percent is above the range of high or very high utilization for a longer period of time. Even a high CPU load is not necessarily a cause for concern, it merely indicates that a lot of computing needs to be done on your site. In periods of high traffic, for example, you should even expect to see a high CPU load.
My site is overloaded - what can I do?
If your site is overloaded, i.e. shows a CPU load significantly over 100% for a longer period of time, your website may experience errors and failures. There is one important point to remember here: an overloaded site is only ever a symptom of a problem, and not the problem itself. The real issue could be, for example, too much traffic.
If your website is overloaded, you need to start looking for the real issue right away. Typical reasons for overloaded websites include:
High traffic => can be analyzed using your access logs
Bot traffic and (D)DoS Attacks => can be analyzed using your access logs
Large computing operation on your Box, e.g. a data export
Hanging cronjobs
RAM usage
The total size of your memory is displayed in your RAM graph. How much RAM is available to you also depends on your Box's hosting plan. A Starter Box has 2 GB of RAM and a Pro XL Box 8 GB.
The x-axis (horizontal axis) shows the time, the y-axis (vertical axis) shows your RAM usage in GB. Just like in the CPU graph, the two colored lines indicating the 70 and 85 percent thresholds simply serve as reading aids. They do not indicate that your RAM is or was utilized to these levels. The graph itself works exactly the same way as the CPU load chart.
My RAM usage is high - why and what can I do about it?
There are several reasons why the RAM usage on the graph may be high. A high RAM usage does not indicate that your site is unavailable or that it is not working properly. It simply means that your RAM needs to work extra hard at certain times. Plugins are themes that need a lot of RAM to function, for example, can cause high RAM usage.
RAM: When is the RAM overloaded?
Isolated peaks in RAM usage do not mean that your site is overloaded. It would only be overloaded if the RAM usage were at 100% over a longer period of time. Parallel working in the WordPress dashboard can cause an overload, especially when using page builders. Another possible cause is large data imports.
RAM: What is high RAM usage?
If the RAM usage is in the high or very high range for a longer period of time, we refer to this as high RAM usage. Even high RAM usage is not necessarily a cause for concern, as it simply indicates that many processes are taking place on your site. This can occur, for example, if you use plugins or themes that require a lot of PHP memory.
My site's RAM is overloaded - what can I do?
If your site's RAM usage is too high, i.e. it's at 100% for a long period of time, your site may experience errors and become unavailable. As with the CPU load, there is one important point to keep in mind here. High RAM usage is only ever a symptom of the actual problem and not the problem itself. The real problem could be, for example, importing files that are too large.