Short Session Timeout and Session Timeout in Excel Services - Part 2

This is the table I promised in my previous post. It basically gives you some ideas about when you should change the settings for Session Timeout and Short Session Timeout on your server:

 

You should…	When you…
Lower Short Session Timeout (only applies to EWA scenarios)	When you have a low “Max Sessions Per User” setting – in those cases, you may have users hitting an error if they have too many sessions opened that are pending for closure. When you have a Trusted Location that contains files that are mostly static and have little to no interaction on them. In that case, you can have Short Session Timeout at a real low number If you have A LOT of users hitting your server all the time. In that case, you may notice some overall performance boost if you lower this timeout. Your users may end up getting error messages here and there which will make them reload the workbook.
Increase Short Session Timeout (only applies to EWA scenarios)	You should do that if you have the opposite situation of what I described above. Namely: If you have a Trusted Location with many highly interactive workbooks and you actually expect your users to interact with them. When you only have a few users hitting the server (as would happen in a departmental installation for example), you could increase the this number to give your users a potentially better user experience/
Lower Session timeout	If you have a lot of users hitting a lot of workbooks such that you find your server reaching memory starvation often – when that happens, you should really upgrade your hardware, but, in the mean-time, it may be worth it to reduce the Session Timeout setting so that the server can get rid of session more quickly. If your main user scenario on a certain trusted location is to open up excel workbooks, do one or two interactions with it (to get some more information) and then close Internet Explorer, it may be beneficial for your overall server performance if you reduce the session timeout.
Increase Session Timeout	If your users use workbooks in a certain trusted location heavily and are doing a lot of analysis in them, you may want to up the session timeout for that trusted location so that they do not lose their work when they go grab a coffee. If you have a trusted location used mostly for API work that does a lot of extra processing (outside of calling into Excel Services), you may want to up your timeout significantly to make sure the process does not fail because the session goes away (there’s an easy workaround here – you can always tell them to keep making simple calls (say, get the A1 cell) to sessions so that they are kept alive.