2012/9/20 Mark Thomas <ma...@apache.org>: > On 09/09/2012 19:51, Mark Thomas wrote: >> On 09/09/2012 19:44, Mark Thomas wrote: >>> This is part of issue b) in Konstantin's comments in TOMCAT-NEXT.txt >>> >>> The current DirContext implementation supports caching in most but not >>> all circumstances. It would be possible to insert a cache into the >>> StandardRoot implementation but I am not convinced it is necessary. The >>> read-cache built into most HDDs may be sufficient. Before starting a >>> cache implementation, I would like to see some performance test cases >>> that demonstrate that the DirContext implementation with caching is >>> significantly faster than the new implementation without caching. >> >> I would add that if even if the new implementation without caching >> performs roughly the same as the old implementation with caching but >> adding caching makes the new implementation even faster than that would >> also convince me of the need to add caching although not with the same >> priority. > > And that is why we do performance testing rather than making assumptions > about what we think the performance will be. > > A simple JMeter test requesting the same static file over and over again > shows that the original DirContext implementation is around 5 times > faster than the new Resources implementation. > > I think the do we need caching question has just been answered firmly "Yes!" > > Using YourKit, I can see where problems are. I can improve the new > implementation to only 3 times slower with some very simple caching > within a single request but for improvement beyond that we will need > caching of resources across requests that includes caching of content. > > I plan to look at this next. >
Hi, Mark! I suspect the slowest scenario will be when a file is served from a META-INF/resources directory of a jar file. I wonder what the numbers will be and whether there is already some caching to prevent re-opening the jar file on each access. There is a related issue in WebappClassLoader that I filed here: https://issues.apache.org/bugzilla/show_bug.cgi?id=52448 I think I'll have time for more detailed review on this weekend. Best regards, Konstantin Kolinko --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
