by
dcooper@jade.co.nz >> Thu, 2 Jun 2005 8:57:48 GMT
As with other technologies, the distribution of web sessions/requests to web application servers/threads (in JADE terms, web apps or processes) is application and hardware dependent.
However, as an indicator, I know of a site that processes on average 3.15 web requests per second (peaks will be higher than this) from perhaps 250 to 350 concurrent web sessions, using 30 web apps spread across 3 web app server nodes (30 web apps + 3 web app server nodes = 33 process licenses in JADE 6, in addition to whatever else is running in the system). This is a large system that requires short queue depths and fast response times, and runs on grunty gear.
So in this case, they're running about 10 concurrent sessions per web app. With the normal caveat of assuming a similar application profile to hardware ratio (ie: you've got the right size gear to run your system), 10 concurrent sessions per web app is a good place to start and we'd normally expect to be able to achieve this easily. Without knowing anything about a system, it's usage profile or the hardware it's going to run on, I'm uncomfortable recommending much more than 50 (genuinely, actively) concurrent sessions per web app.
So for the example you presented, you've got a range of 2 web apps (at 50 concurrent sessions per web app) through to 10 web apps (at 10 concurrent sessions per web app), all of which we'd expect to run inside a single web app server node. If all you're running are these web apps plus a database server node (which requires one process license), that's a range of 4 to 12 process licenses (the web app server node requires a process license as well).
If this is a *new* JADE 6 license (as opposed to extending an existing one), you can purchase a Production Process Base Kit for only US$600. This gives you 10 production process licenses. Given that license and my assumptions above, you'd be able to run up to 8 web apps (8 web apps, plus one web app server node, plus one db server node), which for 100 concurrent sessions would give you a loading of 12 to 13 sessions per web app. Given appropriate hardware, I'd expect this to be a more than comfortable loading, so that's where I'd start.
Dean.