Ooh, that is a nasty one. Is this JDK 7 only or also in 6? It looks like the "-XX:ConcGCThreads=1" option is a workaround, is that right?
We've had some 1.6 JVMs behave in the same way that bug describes, but I haven't verified it is because of finalizer problems. wunder On Sep 19, 2012, at 5:43 AM, Erick Erickson wrote: > Two in one morning.... > > The JVM bug I'm familiar with is here: > http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7112034 > > FWIW, > Erick > > On Wed, Sep 19, 2012 at 8:20 AM, Shawn Heisey <s...@elyograg.org> wrote: >> On 9/18/2012 9:29 PM, Lance Norskog wrote: >>> >>> There is a known JVM garbage collection bug that causes this. It has to do >>> with reclaiming Weak references, I think in WeakHashMap. Concurrent garbage >>> collection collides with this bug and the result is that old field cache >>> data is retained after closing the index. The bug is more common with more >>> processors doing GC simultaneously. >>> >>> The symptom is that when you run a monitor, the memory usage rises to a >>> peak, drops to a floor, rises again in the classic sawtooth pattern. When >>> the GC bug happens, the ceiling becomes the floor, and the sawtooth goes >>> from the new floor to a new ceiling. The two sizes are the same. So, 2G to >>> 5G, over and over, suddenly it is 5G to 8G, over and over. >>> >>> The bug is fixed in recent Java 7 releases. I'm sorry, but I cannot find >>> the bug number. >> >> >> I think I ran into this when I was looking at memory usage on my SolrJ >> indexing program. Under Java6, memory usage in jconsole (remotely via JMX) >> was fairly constant long-term (aside from the unavoidable sawtooth). When I >> ran it under Java 7u3, it would continually grow, slowly ... but if I >> measured it with jstat on the Linux commandline rather than remotely via >> jconsole under windows, memory usage was consistent over time, just like >> under java6 with the remote jconsole. After looking at heap dumps and >> scratching my head a lot, I finally concluded that I did not have a memory >> leak, there was a problem with remote JMX monitoring in java7. Glad to hear >> I was not imagining it, and that it's fixed now. >> >> Thanks, >> Shawn >> -- Walter Underwood wun...@wunderwood.org
