Operating System Monitor Data: CPU (SAP Library

Operating System Monitor Data: CPU

Definition

The following data about CPU usage is displayed for every CPU, broken down as percentages by:

Users
System
Times in which the CPU had no task to perform or was waiting for an input/output (idle)

Many factors could lead to an excessively high CPU utilization, and you should therefore perform a detailed analysis. If the problem was caused by too many active processes in the host system, you could, for example, transfer CPU-intensive programs to times when there is a lower system workload, or to other host systems. You could also increase the number of CPUs or upgrade the CPU(s).

Note

When calculating the hourly value for the last 24 hours, these values are averaged over all CPUs of a host.

Other Values Collected

Number of CPUs
Interrupts per second/hour
System calls per second/hour
Context switches per second/hour
Average number of waiting processes for the last minute, last five minutes and the last 15 minutes

This is the number of processes for each CPU that are in a wait queue before they are assigned to a free CPU. As long as the average remains at one process for each available CPU, the CPU resources are sufficient. As of an average of around three processes for each available CPU, there is a bottleneck at the CPU resources.

In connection with a high CPU usage, a high value here can indicate that too many processes are active on the server.
In connection with a low CPU usage, a high value here can indicate that the main memory is too small. The processes are then waiting due to excessive paging.

Detail data for the processes that cause the largest CPU load:

Process ID
Owner of the process
Command that started the process
Absolute and percentage CPU usage by the process
Resident process size in kilobytes
Priority of the process

Use

The system displays the specified data when you call the operating system monitor.

The system displays the current detail data for the largest CPU users, if they choose Detail analysis menu → Goto → Current Data → Snapshot → Top CPU processes in the operating system monitor (see also Detail Data of the Operating System Monitor).

Check the following performance factors in particular:

Display	Procedure
Is a CPU user constantly active?	Check whether the process is in an endless loop.
Is the average load > 3 (more than three processes are waiting for the CPU)?	Check whether all processes with high CPU usage (memlog, r3trans, nwengine, brbackup...) are necessary.
Is the usage of the CPU zero percent?	Check the analysis for the previous hours.

Note

SAPGUI should not be running on the application server.
You can also display SAP work processes with high CPU usage with the SAP process overview. The SAP process overview displays the ABAP program that is using the CPU.

Operating System Monitor Data: File System and LAN

Operating System Monitor and Operating System Collector SAPOSCOL initial pages.