Memory Usage (One check per server)

The Memory Usage check monitors the following indicators:

RAM Used

Is the total memory minus the available memory. Unused pages of memory and pages of memory returned to the operating system when a process has either quit or its working set was reduced to comply with system resource requirements are placed on one of the above three lists.

By default the Agent will alert if the average available memory falls below 10MB.

Non-pageable memory

Consists of memory that was allocated to processes which have either exited abnormally or have not returned the memory to the Operating System for reuse and memory in use by running processes. As such the operating system cannot swap such memory from physical RAM to the pagefile as it is in use.

By default the Agent will alert where the non-pageable memory exceeds 100MB.

The Memory Usage Check polls the selected Memory Performance Indicators every 5 seconds and averages this out over the monitored period (5 or 15 minutes).

Where the average for any indicator exceeds the entered threshold figure an Alert is generated.

Commit Charge

Is the demand for memory and may be thought of as the number of bytes that have been allocated to processes by the operating system has committed a RAM page frame or page slot in the pagefile to.

The Agent will alert if the average committed bytes is greater than the physical RAM (non-configurable).

Swap Usage (percentage usage)

Contains memory pages used by a process that are not stored in physical RAM. The paging file can be resized to accommodate the additional memory requirements of the running processes and problems may occur where the systems paging file is inadequately sizes for the paging activity of the system.

By default the Agent will alert if the average pages file usage exceeds 70%.

Pages per second (hard page faults only)

Is where the system attempts to access a virtual memory page that is not currently the working set in the physical memory and has to be retrieved from the disk resulting in a delay.

By default the Agent will alert if the average pages per second is above 20 per second.


Please refer to the following image for an example of the Memory Usage information available from the Dashboard.