> > > If you have control of the CF server settings, consider > > > enabling "Single Threaded Sessions" in the LOCKING section > > > of the CF Administrator. Then you don't need to lock any > > > session variable references. > > > > Keith, what I have found with this is a severe degradation > > in performance in any reasonable sized application when this > > is selected. Just my experience. > > That's contrary to my experience and to the CF documentation. > I've seen virtually no degradation of performance.
Hi again, Keith! Every time this topic comes up, you always state that you've never seen any degradation in performance with single-threaded sessions, and strongly recommend its use. I respond by saying that I have seen significant performance degradation for applications under load generated by load-test tools and by real users. So, here's my response, once again. > Here's what the CF (version 5 CFLOCK) documentation says > about the Single Threaded Sessions setting... > > "This feature may have an effect on performance depending on > the request pattern. For example, the total response time may > increase if an application has multiple frames that can be > refreshed at once, thus causing multiple requests to queue > and wait to be processed." > > It wouldn't surprise me that there are some conditions under > which you would *not* want to enable Single Threaded Sessions. > More guidance from Macromedia would be helpful in this area. > > I highly recommend that people try the setting and decide for > themselves. I heartily agree with your suggestion for people to try the setting and decide for themselves. That's what load-test tools are for. Nevertheless, it strikes me as kind of specious for you to state that you've seen no degradation of performance without noting that you haven't tested the setting under load, as you've stated in the past. Of course, if you've done so since then, and you still didn't see any performance degradation, that would be a different matter. But, I suspect that this isn't the case, since every time I've done so, the server took a beating with that setting. Also, I think you're misreading the documentation, since you state that Mike's anecdotal evidence conflicts with the documentation, while the portion that you quote specifically mentions performance degradation. Why do you think that the documentation mentions this as a potential problem? As for more guidance from MM, well, they give you enough rope for you to hang yourself - I'll agree that there are times when you may be better off using this setting as opposed to writing locks throughout your codebase, but it's up to the individual developer to perform his own cost-benefit calculus. In any case, if your applications aren't going to support the amount of load that would be necessary to cause performance degradation problems (and you're sure that they never will have to support that amount of load), then there's nothing wrong with using the setting. Of course, in that case, there are all kinds of corners you might cut and not suffer for it. Applications can have many problems that aren't apparent until they're run under load. If I had a dollar for every time I ran into a problem like this, in which an application that works fine during functionality testing fails under load - oh, wait, I DO have a dollar for every time, never mind. Too many developers learn the hard way that something which seems perfectly acceptable during development may fail catastrophically when the server is pushed to its limit - and far too often, they learn this with real users. Finally, this may become a moot point once CF MX is widely adopted. Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ voice: (202) 797-5496 fax: (202) 797-5444 ______________________________________________________________________ This list and all House of Fusion resources hosted by CFHosting.com. The place for dependable ColdFusion Hosting. FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Archives: http://www.mail-archive.com/[email protected]/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
