CPU Load on VPS: How to Find Out What Loads the CPU?

CPU load in VPS servers — is one of the key metrics that can seriously affect the performance and stability of the system. Recent studies show that 68% system failures occur precisely because of high CPU load. Therefore, it is important to understand what loads the CPU and how to control it. In this article, we will consider how to identify the causes of high load and optimize the operation of a virtual server.

What is CPU load in VPS?

Simply put, CPU Load shows how many tasks are currently being processed or waiting to be executed. This is an important indicator that reflects the current state of the system. If the processor is overloaded, it can slow down the execution of tasks and degrade the performance of all applications running on the server.

Load metrics are typically displayed as an average over three time intervals: 1 minute, 5 minutes, and 15 minutes. For example:

• 1 minute value reflects the instantaneous load over the last minute.
• 5 minute value smooths out short-term fluctuations and shows a more stable indicator.
• 15 minute value helps to see the big picture over a longer period.

What load is considered normal?

The optimal load level depends on the number of processor cores and the specific tasks the system performs. For a single-core processor, a value below 1.0 is considered normal, as this means that the processor handles all tasks without delays. If this indicator is above 1.0, it means that some processes are starting to wait for their turn, which can slow down the system.

For multi-core processors, the load is distributed among the cores. For example, for a processor with four cores, a value of 4.0 indicates that all cores are fully utilized. If the load is higher, it may indicate overload.

Causes of high CPU load

1. Intensive computational tasks. Performing complex calculations, such as processing large amounts of data or rendering video, can put a lot of strain on the processor.
2. Too many simultaneous tasksRunning multiple applications and processes at the same time can lead to a lack of computing resources.
3. Problematic or looping processes. Sometimes processes can use more resources than they need or get stuck in an infinite loop, which increases the load on the CPU. This is especially true for improperly optimized software.
4. Attacks on the server — DDoS attacks or malware can consume processor resources, slowing down the system.

How to reduce CPU load?

If your VPS CPU load becomes critical, there are several ways to reduce it:

1. Termination of problematic processes. Using top or htop, you can quickly find and terminate processes that are overloading the system.

   kill -9 

   Where <PID> — this is the identifier of the problematic process

2. Application Optimization. Update programs and scripts to the latest version to eliminate memory leaks and other bugs that cause CPU overload.
3. Setting up autoload. Sometimes the server loads with many unnecessary services. Check and disable everything unnecessary:

   systemctl list-unit-files --type=service

4. Using cachingIf your server serves a website, implementing caching systems such as Redis or Memcached can significantly reduce CPU load.
5. Scaling resources. If none of the methods help, perhaps the server simply does not have enough resources. In this case, it is better to switch to a tariff with a more powerful processor from the SIDATA provider.

How to track CPU usage on VPS?

There are various commands for monitoring CPU load in Unix-like systems:

• top — a command that displays real-time information about processor load, memory consumption, and running processes.
• uptime - allows you to quickly see how long the system has been running and what the load was in the last 1, 5 and 15 minutes.
• p.s. — displays a list of running processes with their CPU and memory usage. For example, the command (see below) can show the 10 processes with the highest CPU usage.

ps -eo pcpu,pid,user,args | sort -k 1 -r | head -10

For Windows users, the most convenient tool is the Task Manager, which shows the processor load in real time. You can also use the Resource Monitor by entering the command resmon in the Run line (Win+R).

Difference between booting and booting to kernel

When working with VPS servers, it is important to understand the difference between the overall CPU load and the load per core. These two metrics allow you to more accurately assess how efficiently your server resources are being used and where a performance bottleneck may be occurring.

What is total load and load per core?

• Total CPU load — is a metric that shows how many tasks are simultaneously processed by the processor or waiting to be processed in a queue. It is measured as an average value over different time intervals: 1, 5 and 15 minutes.
• Loading onto the kernel — is a metric that shows the load on each individual processor core. If your VPS has multiple cores, it is important to consider not only the overall load, but also the distribution of this load across the cores.

Why is this important?

The difference between these metrics is that single-core and multi-core processors operate differently.

• Single core processor: all tasks are executed sequentially on one core. If the load exceeds the value 1.0, this means that the processor is fully loaded and additional tasks will have to wait for their turn.

• Multi-core processor: tasks can be distributed across multiple cores, allowing more tasks to be processed simultaneously. This is where the importance of 1.0 means loading one core, and for a processor with 4 cores the normal value will be 4.0.

Examples in practice

1. Single Core VPS: Let's imagine that you rent a VPS with one core from SIDATA. Your system is performing tasks under load. 1.2. This means that one core is fully loaded, and another 20% tasks have to wait for their turn. For example, if a server is running a website, a database, and background scripts at the same time, some tasks will be delayed, causing slow page loading and query execution.

2. Multi-core VPS: Now imagine you have a 4-core VPS. If the total load is 4.0, this means that each of the four cores is loaded at 100%. In this situation, the server is working at its maximum capabilities, but there are no delays yet. However, if the load increases to 6.0, this means that two additional task streams are forced to wait. For example, if you are sending out mass mail or processing large amounts of data, the server will begin to slow down.

How to reduce CPU load?

If the server is overloaded, it can negatively affect its performance. There are several ways to reduce the load:

1. Termination of problematic processes. Teams like top or p.s. will help you identify applications that are consuming the most resources and terminate them if necessary.
2. Updating software and drivers. Outdated versions may contain errors that increase the load on the system. Updating helps optimize the work.
3. Reinstalling or rolling back programsIf an application consistently causes high load, you can reinstall it or roll back to a more stable version.
4. Rebooting the serverSometimes a simple reboot will solve problems with temporary processes that may be stuck in the system.

Summary

Monitoring CPU load is an integral part of managing virtual servers. We SIDATA We offer reliable solutions for renting VPS and VDS, which allow you to flexibly configure the server to your needs and monitor its condition. Maintaining the load at a level below 70% helps extend the service life of the equipment and ensure stable operation of applications.

Using monitoring tools and timely detection of problematic processes allows you to optimize the operation of the virtual server and avoid possible failures. It is important to regularly check the system status and, if necessary, adjust its settings so that the rented VPS continues to operate stably and without interruptions.