1.7 Monitoring OS

You can use SQL Developer Web to monitor the CPU utilization, memory, storage, and operating system processes for the compute node.

The widgets in the Overview page are:

• Used and free RAM at the OS level.

• CPU utilization information

• Operating system process information.

• Used and total storage space available on local mounted file systems. The displayed total space for the file systems does not consider the unusable space in each file system.

Memory

The columns in the OS/Memory screen are:

• USER: User that is the owner of the process.

• PR: Priority of the process.

• NI: "NICE" value of the process.

  The Linux niceness scale goes from -20 to 19. The lower the number, the more priority that task gets. The default nice value is zero.

• VIRT: Virtual memory used by the process.

• RES: Physical memory used from the process.

• SHR: Shared memory of the process.

• S: Indicates the status of the process: S=sleep R=running Z=zombie.

• %CPU : Percentage of CPU used by this process.

• %MEM: Percentage of RAM used by the process.

• TIME+: Total time of activity of this process.

• COMMAND: Actual command being monitored.

CPU

The columns in the OS/CPU screen are:

• [ First two columns]: Time that mpstat was run.

• CPU: "all" for all CPUs, or the specific number.

• %USR: Percentage of CPU utilization that occurred while executing at the user level (application).

• %NICE: Percentage of CPU utilization that occurred while executing at the user level with nice priority.

• %SYS: Percentage of CPU utilization that occurred while executing at the system level (kernel).

• %IOWAIT: Percentage of time that the CPUs were idle during which the system had an outstanding disk I/O request.

• %IRQ: Percentage of time spent by the CPUs to service hardware interrupts.

• %SOFT: Percentage of time spent by the CPUs to service software interrupts.

• %STEAL: Percentage of time spent in involuntary wait by the virtual CPUs while the hypervisor was servicing another virtual processor.

• %GUEST: Percentage of time spent by the CPUs to run a virtual processor.

• %IDLE: Percentage of time that the CPUs were idle and the system did not have an outstanding disk I/O request.

Processes

The columns in the OS/Processes screen are:

• USER: User owning the process.

• PID: Process ID

• %CPU: CPU time used divided by the time the process has been running.

• %MEM: Ratio of the process’s resident set size to the physical memory on the machine.

• VSZ: Virtual memory usage of entire process (in bytes).

• RSS: Resident set size, the non-swapped physical memory that a task has used (in KiB).

• TTY: Controlling terminal (TeleTYpewriter) of the process.

• STAT: Multi-character process state.

  Process state codes (STAT column):

  • R: running or runnable (on run queue)

  • D: uninterruptible sleep (usually IO)

  • S: interruptible sleep (waiting for an event to complete)

  • Z: defunct/zombie, terminated but not reaped by its parent

  • T: stopped, either by a job control signal or because it is being traced

  Extra modifiers:

  • < is high-priority (not nice to other users)

  • N is low-priority (nice to other users)

  • L has pages locked into memory (for real-time and custom IO)

  • s is a session leader

  • l is multi-threaded (using CLONE_THREAD like NPTL pthreads do)

  • + is in the foreground process group

• START: Starting time or date of the process.

• TIME: Cumulative CPU time.

• COMMAND: Command being run (with all its arguments).