I want to chime in and give some slightly tangential information about this issue we ran into. (I work with "Z" on this product):
Because we originally thought that our application code was leaking memory (and indeed, it may still be, and the memory profiling options on ColdFusion 7 (JVM 1.4 series) are limited, to say the least, we thought we would go ahead upgrade ColdFusion to the last version of 8.0.1 running on JVM 1.6. (This is all running on 32-bit Windows 2003). Z made the necessary changes to our app and we upgraded our server to CF8. The app ran but not as fast as expected- we expected very fast performance based on many reports of heavy CFC-based apps. (We are aware of the classloader bug in JVM 1.6_04 and experienced the issue I'm describing on JVM 1.6_04, 1.6_11, and 1.6_16, and JVM 1.5_19). Even more surprising than the diminished application performance, it was never very long before the app server's CPU would be pegged at 100%. A few times this happened we were able to peek under the hood with Adobe's Server Monitor app. We saw at least one long running thread during these times referencing Transfer's SoftReferenceHandler. Upon further investigation, we realized that after the app started up, under no load whatsoever the CPU usage would be 25%, 50%, 75%, or 100% (notable b/c this is a 4 core machine). As best as I can tell, the long running thread I observed was completely monopolizing the core on which it was running, preventing the application from serving any other requests. After we rolled back to CF7 for current production, we provisioned a Windows 2003 VM on Amazon EC2 and installed CF8 and our application. We were not able to reproduce the problem that we described, and the performance was more or less as we expected on 8 (reasonably fast considering the minimal CPU power dedicated on the "smallest" EC2 instance). I don't know that any of this will help you, Mark, or anyone else here, but it is an interesting observation and I want to provide as much information as possible to aid in the resolution of this problem. Thanks! Clint > > > Hi Everybody, > > > > We have an e-commerce website developed using Coldfusion 7, Model- > > > Glue, Coldspring and Transfer. Over the past months we have struggled > > > with what we thought was a "Memory Leak". We could see the jrun memory > > > usage climb until it just became unresponsive (queue a bunch of > > > requests and never serve them). We would then have to restart jrun and > > > repeat the process over and over again. > > > > After months of trying to figure out what was going on we finally > > > realized who the culprit was; the Transfer cache. > > > > Now, here's our original cache configuration: > > > > <objectCache> > > > <defaultcache> > > > <maxobjects value="60"/> > > > <maxminutespersisted value="10" /> > > > <accessedminutestimeout value="10"/> > > > <scope type="instance" /> > > > </defaultcache> > > > > <!-- SOME CLASSES WE DONT WANT TO CACHE --> > > > <cache class="Users.Orders"> > > > <scope type="none" /> > > > </cache> > > > .... > > > </objectCache> > > > > It turns out leaving the cache on by default was killing us. Although > > > performance was always great, under heavy load our site would > > > sometimes have to go down every hour. > > > > After some experimenting we decided to turn the cache off by default > > > and be very conservative on the objects we cached. Our latest > > > transfer.xml looks something like this: > > > > <objectCache> > > > <defaultcache> > > > <scope type="none" /> > > > </defaultcache> > > > <cache class="Users.Customer"> > > > <maxobjects value="60"/> > > > <maxminutespersisted value="10" /> > > > <accessedminutestimeout value="10"/> > > > <scope type="instance" /> > > > </cache> > > > <cache class="Products.ProductType"> > > > <maxobjects value="10"/> > > > <maxminutespersisted value="30" /> > > > <accessedminutestimeout value="10"/> > > > <scope type="instance" /> > > > </cache> > > > ... > > > </objectCache> > > > > I guess the main question I have is whether anyone here has had > > > similar experiences or has any rule's of thumb when it comes to > > > caching objects. We are still unsure on whether the behavior we were > > > experiencing was an actual memory leak or just poor cache management. > > > Any comments? > > > -- > > E: [email protected] > > T:http://www.twitter.com/neurotic > > W:www.compoundtheory.com --~--~---------~--~----~------------~-------~--~----~ Before posting questions to the group please read: http://groups.google.com/group/transfer-dev/web/how-to-ask-support-questions-on-transfer You received this message because you are subscribed to the Google Groups "transfer-dev" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/transfer-dev?hl=en -~----------~----~----~----~------~----~------~--~---
