Windows Server Memory Usage
Wormly Metrics monitors Windows RAM usage - among thousands of other metrics.
RAM is often a strained resource in Windows®-based web servers. ASP.NET applications in particular have large memory requirements due to the virtual machine architecture that underpins the platform.
Wormly monitors the RAM usage of your web servers over time, presenting this information in the following trend graph:
Physical RAM Usage. Indicates the proportion of the systems' physical RAM that is currently utilized. As physical RAM becomes consumed, the system will increasingly need to swap memory pages to and from the disk, which significantly degrades server performance.
Pagefile Usage. Indicates the proportion of the Windows swapfile currently utilized. The swapfile is the disk space allocated for storing memory pages that are swapped in and our of the physical memory.
Note that the swapfile utilization does not directly correspond with virtual memory utilization - i.e. swapfile space committed is not necessarily being used by the system as virtual memory.
Virtual RAM Usage. Indicates the proportion of virtual memory currently utilized. Generally you should expect this figure to remain low - around 1% - on systems with sufficient physical RAM.
If the virtual RAM usage level increases, it signals the exhaustion of physical RAM, and corresponds with a severe performance degradation caused by swapping pages in and out of the pagefile.
By understanding your Windows web-servers' memory usage trends, you will be able to plan for future capacity needs, and help avoid application performance issues before they impact upon your customers' experience.