On Friday, Jan 3, 2003, at 13:34 US/Pacific, Dick Applebaum wrote: > According to what I have read, with CFMXJ2ee he could run a CFMX server > context (instance) for each site -- or even for each application within > a site -- and this should perform better than a single CFMX Standalone > server.
Yes, on a multi-processor system. > I haven't seen it mentioned, but wouldn't another advantage be that > each context would be able to use "dangerous" CFMX features such as > cfobject, custom tags, etc., because the contexts are isolated. Well, some of those features are considered sufficiently "dangerous" by hosting companies that I don't know they'd enable them anyway. However, CFMX for J2EE does indeed allow you to give each 'install' (context root) its own CF Admin so each context is fairly well sandboxed. Don't confuse multiple context root instances with multiple server instances tho': if I install a context root /corfield.org on server instance cfmx1 and also install /lacara.com on the same server instance, they will share a JVM environment (at least, as far as I understand what I'm seeing on my servers here). That means that an application on one context root *can* impact another (e.g., by eating all JVM memory). In order to get true separation, you need multiple server instances, each of which gets its own JVM. See recent articles in my blog for various scenarios involving multiple server instances and multiple context roots. > Do multiple contexts outperform a single, shared context (standalone > server)? Multiple server instances would probably outperform a single, shared context (J2EE or standalone) on a multi-processor system. In general, CFMX for J2EE will outperform CFMX Standalone, especially on a multi-processor system. > Is there any performance data or experiences available? See the ColdFusion whitepapers section on mm.com which has a performance brief for IBM WebSphere - by way of example. > Is there a practical limit on the number of CFMX contexts that can run > concurrently on a app server like JRun? Again, don't confuse contexts for instances. Multiple contexts run in a single JVM. Multiple instances run in separate JVMs. The number of *instances* you can have depends on your hardware. I'm working with servers that have 8-12Gb RAM so I can have multiple instances with each JVM set to use about 3Gb memory. On each of those instances I have two contexts - purely to separate two groups of applications from each other. I have multiple identical servers and cluster them using JRun. > Given the same hardware, how would/should this compare to the number of > users that could share a CFMX standalone server? See the performance brief mentioned above. > Am I missing any other limitations/advantages of CFMXJ2ee for > shared-hosting? See my comments about contexts vs instances. Sean A Corfield -- Director, Architecture Web Technology Group -- Macromedia, Inc. tel: (415) 252-2287 -- cell: (415) 717-8473 aim: seancorfield -- http://www.macromedia.com An Architect's View -- http://www.corfield.org/blog/ Introducing Macromedia Contribute. Web publishing for everyone. Learn more at http://www.macromedia.com/contribute ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Archives: http://www.houseoffusion.com/cf_lists/index.cfm?forumid=4 Subscription: http://www.houseoffusion.com/cf_lists/index.cfm?method=subscribe&forumid=4 FAQ: http://www.thenetprofits.co.uk/coldfusion/faq This list and all House of Fusion resources hosted by CFHosting.com. The place for dependable ColdFusion Hosting. Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
