If you notice that the Internet Information Services' (IIS) application pools related to CentreStack are consuming large amounts of RAM nearing the server's capacity, there are a couple of things that you can do to try to remedy this before you consider scaling up (with additional resources/hardware to your existing server) or out (with additional worker nodes to your CentreStack farm).
The first step is to load the following two URLs on a browser on the CentreStack server. Once each page loads, go to your browser's File->Save Page As, or type Control+S to save the XML output.
The output will look something like the following screenshot. Once you have the two outputs as separate files, please send them to email@example.com to open a support ticket.
Now, to remedy the memory problem there are a couple of optimizations that you can try. One is that due to the fact that file preview generation is an expensive process for large files, you should only generate file preview images for relatively small files if you are having memory issues. Under the Cluster Control Panel -> Settings, you should decrease the maximum file size for the setting labeled: "Don't show file icon preview if file size is larger than." Try setting this figure to half of a Megabyte (500KB) from the default 5MB (5000MB) and see if it helps.
The second optimization is to set the UploadDownloadProxy application pool in IIS to recycle itself if it reaches a certain size. If you decide to do this, please do not cap the Virtual Memory usage. Instead, set the Private Memory usage, and make sure that the figure that you use is well under the amount when it starts to impact the server negatively. For example, if the server starts to work slowly once the UploadDownloadProxy or Namespace pool reaches over 5GB, set this number to 4GB (4,194,304 kilobytes).
Furthermore, in order to prevent CentreStack's storage component from going down completely as a result of the automated recycles, you will also need to configure the Rapid-Fail Protection's Maximum Failures under the UploadDownloadProxy application pools' advanced settings. Set this figure to a relatively large number, such as 50.
For more information about Memory tuning on the MSDN website, please visit: https://msdn.microsoft.com/en-us/library/ff647813.aspx#scalenetchapt17_topic9