Application server usage

[allistar]

Hi all,
One of my clients has a rule of thumb of "25 users per application server". We have found that, anecdotally, more than that and the performance impact starts to become apparent. So 90 users would require 4 app servers. I know that this figure will be quite dependant on the Jade application itself, but does anyone else have a recommendation for this for their users?

[BeeJay]

We normally go with a rule of thumb of a maximum of 30 users per AppServer for our application. This is much easier to manage now with connection balancing across AppServers built in to Jade itself. It also helps that each additional AppServer Node is no longer using up a process licence for Jade's clientBackground process in each AppServer Node.

Cheers,
BeeJay.

[allistar]

Yes, load balancing makes a big difference to this, especially for large sites. <shameless plug>we've been load balancing application servers for many years now, thanks to this being built into the Connection Manager sofware which has load balancing built in (as well as a lot of other usefull features, including windows mobile support)</shameless plug>.

I'm wondering what it is in particular that causes this performance limit in number of connections to an app server. Is it related to cache locking? Threads available? IO issues?

[Matthew]

Unfortunately this is a bit of one of those how long is a piece of string sort of questions, but in an "average" 32 Bit environment it is likely to be in the 20 -30 user vicinity.

Too few a users and your not gaining the efficiencies of sharing common objects in cache, too many and you will encounter what is referred to as node contention . Node contention is described in a bit more detail in the JADE design tips for better performance white paper http://www.jadeworld.com/downloads/jade ... Design.pdf.

It is extremely rare in a 32Bit environment for the suitable number to be in excess of 40, JADE 6.3 - 64 Bit changes the dynamics significantly.

If you're unable to fully load test or analyze the particulars of the system, on balance you are probably better off erring towards fewer users.

Given the thread involves plugs already <shamelessplug>Of course there is always the option of enlisting the JADE Benchmark Lab to help you out in the testing or analysis work. </endshamelessplug>