Name
- system.cpu.guest
- Percent (Unit)
- The percent of time the CPU spent running the virtual processor. Only applies to hypervisors.
- system.cpu.idle
- Percent (Unit)
- Percent of time the CPU spent in an idle state.
- system.cpu.iowait
- Percent (Unit)
- The percent of time the CPU spent waiting for IO operations to complete.
- system.cpu.stolen
- Percent (Unit)
- The percent of time the virtual CPU spent waiting for the hypervisor to service another virtual CPU. Only applies to virtual machines.
- system.cpu.system
- Percent (Unit)
- The percent of time the CPU spent running the kernel.
- system.cpu.user
- Percent (Unit)
- The percent of time the CPU spent running user space processes.
计算公式
system.cpu.guest = %guest
system.cpu.idle = %idle
system.cpu.iowait = %iowait
system.cpu.stolen = %steal
system.cpu.system = %sys + %irq + %soft
system.cpu.user = %usr + %user + %nice
数据来源
针对Linux系统，DataDog Agent使用mpstat实时监控工具，获取CPU相关的Metrics。DataDog Agent并没有获取各个CPU的详细信息，而是所有CPU的平均值。
mpstat是Multiprocessor Statistics的缩写，是实时系统CPU监控工具。监控信息来自内核文件：/proc/stat
mpstat输出内容示例
# mpstat 1 3
Linux 3.10.0-693.21.1.el7.x86_64 (ip-172-31-22-228.cn-north-1.compute.internal) 08/29/2018 _x86_64_ (8 CPU)
05:59:14 AM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
05:59:15 AM all 8.06 0.13 7.15 0.00 0.00 0.78 0.13 0.00 0.00 83.75
05:59:16 AM all 14.61 0.00 8.16 0.00 0.00 1.05 0.26 0.00 0.00 75.92
05:59:17 AM all 18.69 0.13 5.75 0.00 0.00 0.78 0.13 0.00 0.00 74.51
Average: all 13.78 0.09 7.02 0.00 0.00 0.87 0.17 0.00 0.00 78.07
各个字段含义如下(internal时间段内的平均值)
CPU Processor number. The keyword all indicates that statistics are calculated as averages among all processors.
%usr Show the percentage of CPU utilization that occurred while executing at the user level (application).
%nice Show the percentage of CPU utilization that occurred while executing at the user level with nice priority.
%sys Show the percentage of CPU utilization that occurred while executing at the system level (kernel). Note that this does not include time spent servicing hardware and software interrupts.
%iowait Show the percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request.
%irq Show the percentage of time spent by the CPU or CPUs to service hardware interrupts.
%soft Show the percentage of time spent by the CPU or CPUs to service software interrupts.
%steal Show the percentage of time spent in involuntary wait by the virtual CPU or CPUs while the hypervisor was servicing another virtual processor.
%guest Show the percentage of time spent by the CPU or CPUs to run a virtual processor.
%gnice Show the percentage of time spent by the CPU or CPUs to run a niced guest.
%idle Show the percentage of time that the CPU or CPUs were idle and the system did not have an outstanding disk I/O request.
