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Xiaobian to share with you the CentOS system load example analysis, I believe most people do not know how, so share this article for your reference, I hope you read this article after a lot of gains, let us go to understand it!

The load average in the echo of the uptime command is similar to the w command in that it represents the average number of processes in the queue for the past 1, 5, and 15 minutes.

What needs to be noted here is the output value of load average. The size of these three values cannot be greater than the number of logical CPUs in the system. For example, there are 4 logical CPUs in the system in this output. If the three values of load average are greater than 4 for a long time, it means that the CPU is very busy and the load is very high. It may affect the system performance, but occasionally greater than 4, it does not need to worry. Generally, it will not affect the system performance. On the contrary, if the output value of load average is less than the number of CPUs, it means that the CPU is still idle, such as the output in this example, the CPU is relatively idle.

The average load is 0 when the CPU is completely idle and 1 when the CPU is saturated

A system load of 0 means that there is no vehicle on the bridge.

The system load is 0.5, which means that half of the sections of the bridge have vehicles;

The system load of 1.0 means that all sections of the bridge are occupied, which means that the bridge is "full." It must be noted, however, that the bridge has been able to pass smoothly up to this point;

The system load of 1.7 means that there are too many vehicles, the bridge is already full (100%), and the vehicles waiting behind the bridge are 70% of the deck vehicles. Similarly, a system load of 2.0 means that there are as many vehicles waiting to get on the bridge as there are on the deck; a system load of 3.0 means that there are twice as many vehicles waiting to get on the bridge as there are on the deck. In short, when the system load is greater than 1, the vehicle behind must wait; the greater the system load, the longer the bridge must wait.

The CPU system load is basically equivalent to the analogy above. The capacity of the bridge is the maximum workload of the CPU; the vehicles on the bridge are processes waiting for the CPU to process.

If the CPU is processing at most 100 processes per minute, then a system load of 0.2 means that the CPU is processing only 20 processes in that minute; a system load of 1.0 means that the CPU is processing exactly 100 processes in that minute; and a system load of 1.7 means that there are 70 processes queued for the CPU to process in addition to the 100 processes the CPU is processing.

When the system load continues to be greater than 0.7, you must start investigating what the problem is and prevent the situation from deteriorating.

When the system load continues to be greater than 1.0, you have to find a solution to reduce this value.

When the system load reaches 5.0, it indicates that your system has a serious problem, no response for a long time, or close to a crash. You shouldn't let the system reach this value.

So, 2 CPUs means that the system load can reach 2.0, when each CPU reaches 100% of the workload. Generalizing, the maximum acceptable system load for a computer with n CPUs is n.0.

cat /proc/cpuinfo"command to view CPU information. The command "grep -c 'model name' /proc/cpuinfo" directly returns the total number of CPU cores.

If the system load is greater than 1.0 for only one minute and less than 1.0 for the other two periods, this indicates that it is only a temporary phenomenon and that the problem is not serious.

If the average system load is greater than 1.0 (after adjusting for CPU cores) for 15 minutes, the problem persists and is not temporary. So you should focus on the "15-minute system load" as an indicator of how well your computer is working.

The above is "CentOS system load sample analysis" all the content of this article, thank you for reading! I believe that everyone has a certain understanding, hope to share the content to help everyone, if you still want to learn more knowledge, welcome to pay attention to the industry information channel!

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