Re: Overwhelming a Web Application Server

Nathan Andelin skrev:

From: Thorbjoern Ravn Andersen
Weeeeell, how would you determine that limit?

Good question. It seems that defining and configuring a session limit by application or product could be a matter of setting up a database table/maintenance program or configuration file for that purpose. The harder question is how to enforce it. It seems that the application server would need to know precisely the number of active sessions. Active sessions would vary as new ones are established, inactive ones expire, while others may be canceled by user's clicking an "exit" link. Can that be done?

I was being a bit facetious. The point here is that you CANNOT determine this number accurately ahead of time, so stating that "only 5000 sessions please" is bound to either be too low or - worse - too high a number.

Besides, people tend to dislike those "go away I'm too busy" websites.

And why should it be a constant?

Not sure it should be a constant, unless an ISV would like to enforce a user-based license restriction, which seems reasonable to me. Like, I know my web application is hosted on a server and could be used by an almost unlimited number of users, but if you want unlimited use, please pay more.

>From a capacity planning point of view, I like the idea of a system administrator using a maintenance program to maintain a table of session limits by product ID. Let the administrator decide - and change it - whenever.

OS/400 knows how to adjust itself on-the-fly based on performance metrics. Are you suggesting we should settle for anything less O:-)