> You can use Visual VM (https://visualvm.dev.java.net/) to see how the > VM is using memory. I don't think it specifically show a log of GC > activity, but it is pretty clear from the graphs.
Or just use -XX:+PrintGC and maybe -XX:+PrintGCDetails and -XX:+PrintGCTimeStamps. I haven't checked what the code is doing, but if you suspect extremely poor performance due to GC it may be because your application happens to require some amount of memory that is below but fairly close to the default maximum heap size. That may easily cause very frequent GC:s and show up as poor performance. If this is the case, doubling the heap size should fix it (-Xmx...). (The JVM does throw OutOfMemoryExceptions when it decides there is cause too, but it is a difficult heuristic to decide when that is actually the right thing to do. So it's very possible to be in situations that are not quite so bad in terms of time spent doing GC that the JVM throws an exception, yet bad enough to cause very frequent full GC:s at considerable cost in CPU time.) -- / Peter Schuller -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
