AbleCommerce Shopping Cart Software

We have been implementing and maintaining an AC solution for the last 5 years (currently in version 7.0.7), lately, due to an increase of users and other factors we could not identity, the virtual server hasn’t been able to keep up with the load, and the site becomes completely unresponsive.
The diagnostic tool (Dynatrace) seems to indicate a thread lock in the Cache NHibernate class but there doesn’t seem to be a direct correlation between the number of users and the server overload. The pattern seems to be recurrent, if the CPU gets over a certain % the system starts to become increasingly instable, the used memory starts to go UP and when it gets up to 14Gb or so the server completely stops responding and an IIS Reset is necessary.
My question is pretty broad, are these symptoms known? Did any of the other projects experienced any of this behavior? What are the common causes for underperformance in AC?
Thank you in advanced for your answers

A common cause for issues like this could be related to maintenance of the database records. Do you have Activity Logging enabled, and if so, are the records being purged?

Joe Payne is an expert on AbleCommerce databases. He has some helpful info here - viewtopic.php?f=65&t=18900&start=0&hilit=performance

We also have an old FAQ which documents the maintenance and shows how you can check the records.

http://help.ablecommerce.com/index.htm# ... enance.htm

Hope this helps.
Thanks
Katie

I'm curious as to the nHibernate Cache- AC 7.0.7 didn't use nHibernate. Have you added that to the site?

To check your version, go to the Help > About page.