CPU load using top command in CentOS

CentOS uses the top command to load the CPU. CentOS is the product of source code re-Compilation of RHEL (Red Hat Enterprise Linux), and many known bugs have been fixed on the basis of RHEL. Compared with other Linux releases, its stability is trustworthy. During system maintenance, you may need to check the CPU usage at any time and analyze the system status based on the relevant information. In CentOS, you can use the top command to view CPU usage. After the top Command is run, the CPU usage status is displayed in full screen mode and in dialog mode. The top-based command can be used to control the display mode. The command to exit top is q (Press q once in top running ). Enter "top" in the command line to start top, as shown in figure: the full-screen dialog mode of top can be divided into three parts: system information, command input, and process list. Part 1-top line (top) of the system information column: "00:11:04" indicates the current time of the system; "" indicates the operating time from the start of the system to the present; "2 users" is the user currently logged on to the system, more specifically, the number of terminals that log on to a user-connections to multiple terminals of the system from the same user at the same time are considered as connections from multiple users to the system, the number of users here will also be the number of terminals; "load average" is the average value of the current system load, the following three values are the average number of processes one minute ago, five minutes ago, and 15 minutes ago. Generally, when this value exceeds the number of CPUs, the CPU will be hard to load the processes contained in the current system; the second line (Tasks): "59 total" indicates the total number of processes in the current system; "1 running" indicates the number of processes currently running; "58 sleeping" indicates the number of processes in the waiting state, "0 stoped" indicates the number of stopped system processes, and "0 zombie" indicates the number of recovered processes; row 3 (Cpus ): The current CPU usage. The fourth line (Mem) indicates the total memory usage, current usage, idle memory usage, and buffer memory usage. The fifth line (Swap ): indicates that the category is the same as the fourth row (Mem), but this shows the usage of Swap partition (Swap. In general, Swap partitions (Swap) are frequently used and are considered to be caused by insufficient physical memory. The second part is the internal command in the middle part. In the top running column, you can use the top internal command to control the display mode of the process. The internal commands are as follows: s-change the screen update frequency l-close or enable the first line of top information in the first line t-close or enable the first part of the second line of Tasks and the third line of Cpus information m-close or enable the expression N of the first part of the fourth line Mem and the fifth line Swap information. In the order of PID size, the process list P is displayed. In the order of CPU usage, the Process List M is displayed. process list in the order of memory usage size h-show help n-set the number of processes displayed in the Process List q-exit top s-change the screen update cycle part 3-bottom part the PID-specific process list in the process list is periodically updated based on the set screen update time. You can use the top internal command to control the display mode. In general, we maintain the server through remote monitoring, so that the local terminal of the server runs top in real time, which is one of the fast and convenient ways to monitor the server status locally on the server.