I created a very basic WebReport to audit and make recommendations on Relay Cache Sizing to help you figure out if your Relay Caches are too small. You must be able to see the relays in WebReports or in the console for this to work.
I also took the exact same code and wrapped it into a Dashboard.
To use it as a Web Report, just make a new custom WebReport, and paste in the code in this file: https://github.com/jgstew/bigfix-content/blob/master/webreports/RelayCacheSizing.beswrpt
To use it as a Dashboard, make a file called RelayCacheSizing.ojo with the contents here: https://github.com/jgstew/bigfix-content/blob/master/dashboards/RelayCacheSizing.ojo
Once you have RelayCacheSizing.ojo you can use the console debug menu to Load Wizard... and select this file. This will load the Dashboard for your current console session only. It will go away if you close and reopen the console, but it is an easy way to see the data without needing to use WebReports. Make sure you put the .ojo file in an otherwise empty directory before doing this, because the console will make a temporary copy of everything in the directory before loading the Dashboard.
If you do not have the console Debug menu enabled, then you must hit Ctrl+Shift+Alt+D to bring up the Debug Dialog, then click the “Show Debug Menu” checkbox. You can then close the Debug Dialog.
Both of these things are very basic and could look a lot better; in particular the list of relays and cache sizes in the Dashboard displays poorly.
If you find this useful and make improvements, be sure to issue a pull request on GitHub so that we can all benefit.