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The Uptime Infrastructure Monitor agent uses the sar -urWqR 1 command to compare the system counters during a one-second interval. The statistics returned by the agent are averaged for all CPUs on the system.
| Metric | ExplanationDescription | Source |
|---|---|---|
% USR | The percentage Percentage of time that the processor spends in user mode (a processing mode for applications and subsystems). | /proc |
% SYS | The percentage Percentage of time that the kernel spends processing system calls. | /proc |
% WIO | The amount Amount of waiting time that a runable process for a device takes to perform an I/O operation. | /proc |
% Total | The total Total amount of User %, System %, and Wait I/O % | /proc |
Run Queue Length | The percentage Percentage of time that one or more services or processes are waiting to be served by the CPU. | /proc |
Multi-CPU
The Uptime Infrastructure Monitor agent uses the sar and mpstat utilities on a Linux system to collect the metrics in the table below from Linux systems with multiple CPUs. The agent averages the statistics from each CPU using the sar -x SELF -I SUM -P ALL -wu 1 command, which compares the system counters during a one-second interval. The statistics that the agent returns are for the entire system, per CPU.
| Metric | ExplanationDescription | ||
|---|---|---|---|
Us er | The percentage Percentage of CPU user processes that are in use. | ||
Sy ste m | The percentage Percentage of CPU kernel processes that are in use. | ||
Wa it Wait I | The percentage Percentage of time that a process which can be run must wait for a device to perform an I/O operation. | ||
SM TXSMTX | The number Number of read or write locks that a thread was not able to acquire on the first attempt, as reported by the | ||
XC ALXCAL | The number Number of interprocess cross-calls. In a multi-processor environment, one processor sends cross-calls to another processor to get that processor to do work. Cross-calls can also be used to ensure consistency in virtual memory. Heavy file system activity (such as NFS) can result in a high number of cross-calls. | ||
Interrupts | Number | Int err upts | The number of CPU interrupts. |
Tot al | The total Total amount of User %, System %, and Wait I/O%. |
Memory
The Uptime Infrastructure Monitor UIM agent uses the free command to collect the Free Memory metric from a Linux system. The rest of the memory related metrics are gathered by the sar -urWqR 1 command which compares the system counters during a one-second interval. The statistics that the agent returns are for the entire system.
| Metric | ExplanationDescription | Source |
|---|---|---|
Free Memory | The amount Amount of physical memory available to the operating system, system library files, and applications. | /proc/meminfo |
Cache Hit Rate | How often the system accesses the CPU cache. | /proc/meminfo |
PageOut per Second | The rate Rate at which pages were written to disk. | /proc/meminfo |
PageIn per Second | The rate Rate at which pages were read from or written to the disk. | /proc/meminfo |
PageFree per Second | The number Number of pages that are freed from memory each second. | /proc/meminfo |
PageScan per Second | The average Average number of pages that are scanned each second. | /proc/meminfo |
Free Swap | The amount Amount of available free swap space, as a percentage of total available free swap space. | /proc/meminfo |
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