On 16/06/2016 20:37, Peter Robbins wrote: > Hi there, > > I’ve run into the WebappClassLoader jar scanning memory leak resolved > by r1731030 and r1731035 in Tomcat 7 trunk. It appears those changes > made it separately into both 8.0.36 and 8.5.3, but are missing from > 7.0.69 and 7.0.70. Any idea on the timeline of when those would be > released in 7.x?
For the benefit of the archives, this is not a leak. There is increased memory usage but that usage is a) bounded and b) released when the application is unloaded. The current 7.0.x implementation loads the binary content for every class into memory as part of the scanning process. As classes are loaded, the binary content is dropped and the newly created class added. For applications that use most of the classes they ship with, the result is a rapid step in the memory requirements when the application starts rather than a gradual rise over time and the end result marginally increased memory usage. For applications that use few of the classes they ship with, the result is also a rapid step in the memory requirements when the application starts rather than a gradual rise over time but the end result is significantly increased memory usage. I've reviewed the code and the changes in r1731030 and r1731035 are heavily dependent on the WebResources refactoring that took place for 8.0.x and is not present in 7.0.x. This makes implementing a fix for this issue significantly more difficult in 7.0.x. Given the general fragility of resource loading in 7.0.x (itself a significant factor in introducing the WebResources refactoring) I'm currently leaning more towards recommending workarounds for this issue rather than implementing code fixes. Those workarounds boil down to minimising the number of JARs scanned and are covered in the JAR scanning section of [1]. I plan to spend some more time looking at options for fixing this in the code, but my recommendation would be to look at an upgrade to 8.5.x or to minimise the amount of JAR scanning performed if this is an issue for you. Mark [1] http://wiki.apache.org/tomcat/HowTo/FasterStartUp --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
