# shell中检查服务器进程使用cpu

批量检查服务器上的进程cpu负载，采用命令

```
ps -aux --sort=%cpu
```

则输出显示

```
USER        PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root          1  0.0  0.0 196136 12468 ?        Ss    2019  32:45 /usr/lib/systemd/systemd --switched-root --system --deserialize 21
root          2  0.0  0.0      0     0 ?        S     2019   1:23 [kthreadd]
root          5  0.0  0.0      0     0 ?        S<    2019   0:00 [kworker/0:0H]
...
admin     12597  208  2.0 17630628 10803540 ?   Sl   Aug05 2374:53 java -D...
admin    106071  287  2.2 15434760 12101576 ?   Sl   Jul23 56708:30 java -server ...
admin      8601  345  2.3 15496056 12297256 ?   Sl   11:05 800:52 java -server ...
```

可以看到按照 `%cpu` 排序后就很容易找到负载最高的进程，例如再加上 `tail -10` 就可以获得使用cpu资源最高的进程

对于docker环境，如果需要检查特定进程使用cpu的情况，例如syslog-ng进程，可以结合命令

```bash
ps -aux --sort=%cpu | grep syslog-ng | tail -n 3
```

使用top命令也可以查看cpu使用率，不过，top通常是交互模式，如果要命令行采集，采用 `top -b -n 1` 就可以采集一次(`-n 1`)输出，显示内容如下

```
#top -b -n 1
top - 15:07:14 up 244 days, 21:20,  1 user,  load average: 81.88, 89.74, 90.29
Tasks: 2458 total,   4 running, 2452 sleeping,   0 stopped,   2 zombie
%Cpu(s): 50.1 us, 18.8 sy,  0.0 ni, 29.4 id,  0.3 wa,  0.0 hi,  1.5 si,  0.0 st
KiB Mem : 52754140+total, 62239184 free, 31605289+used, 14924934+buff/cache
KiB Swap:        0 total,        0 free,        0 used. 17871446+avail Mem 

   PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
 12597 admin     20   0   16.8g  10.3g  19100 S 517.8  2.0   2411:49 java
  8601 admin     20   0   14.8g  11.8g  14744 S 397.8  2.3 832:50.61 java
106071 admin     20   0   14.7g  11.5g  16728 S 380.0  2.3  56745:29 java
 10930 admin     20   0   22.7g   3.4g  26892 S 231.1  0.7   3284:41 java
103452 admin     20   0   16.8g  12.8g  29640 S 228.9  2.5   5013:20 java
...
```

## 获取cpu的脚本案例

参考 [Get CPU usage via SSH](https://stackoverflow.com/questions/20693089/get-cpu-usage-via-ssh) 提供了获取cpu利用率的案例，我做了一点修改来取样10次求平均值

```bash
top -b -n 10 -d.2 | grep 'Cpu' |  awk '{print $2}' | awk -F% '{ SUM += $1 } END { print SUM/10 }'
```

其中参数：

* `-b` 表示 Batch模式，脚本模式
* `-n 10` 表示取样10次
* `-d.2` 表示显示间隔(Delay time)，数值格式是 `-d ss.tt` 即(`seconds.tenths`)

上述脚本通过 `grep 'Cpu'` 可以过滤出每次top获得的cpu使用率

```bash
top -b -n 10 -d.2 | grep 'Cpu'
```

此时输出的内容类似如下：

```
Cpu(s):  0.8%us,  0.8%sy,  0.0%ni, 60.1%id,  0.5%wa,  0.0%hi,  0.0%si, 37.9%st
Cpu(s):  0.0%us,  0.0%sy,  0.0%ni, 63.0%id,  0.0%wa,  0.0%hi,  0.0%si, 37.0%st
Cpu(s):  1.2%us,  1.2%sy,  0.0%ni, 63.1%id,  0.0%wa,  0.0%hi,  0.0%si, 34.5%st
Cpu(s):  0.0%us,  1.2%sy,  0.0%ni, 64.6%id,  0.0%wa,  0.0%hi,  0.0%si, 34.1%st
Cpu(s):  0.0%us,  0.0%sy,  0.0%ni, 60.5%id,  0.0%wa,  0.0%hi,  0.0%si, 39.5%st
Cpu(s):  1.2%us,  3.7%sy,  0.0%ni, 56.1%id,  0.0%wa,  0.0%hi,  0.0%si, 39.0%st
Cpu(s):  1.2%us,  2.4%sy,  0.0%ni, 67.5%id,  0.0%wa,  0.0%hi,  0.0%si, 28.9%st
Cpu(s):  1.2%us,  0.0%sy,  0.0%ni, 66.3%id,  0.0%wa,  0.0%hi,  0.0%si, 32.5%st
Cpu(s):  0.0%us,  1.2%sy,  0.0%ni, 68.3%id,  0.0%wa,  0.0%hi,  0.0%si, 30.5%st
Cpu(s):  1.2%us,  0.0%sy,  0.0%ni, 68.3%id,  0.0%wa,  0.0%hi,  0.0%si, 30.5%st
```

通用 `| awk '{print $2}' | awk -F% '{ SUM += $1 } END { print SUM/10 }'` 过滤出第2列数据，并以`%`分隔符取出cpu利用率数值进行累加并除以10计算出平均值。


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://huataihuang.gitbook.io/cloud-atlas-draft/develop/shell/bash/check_process_cpu.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.