Hi - I thought that as long as I specified neither -client nor -server, that Server Class detection would automatically invoke the "-server" option.
http://download.oracle.com/javase/6/docs/technotes/guides/vm/server-clas s.html We are running 12-core AMD Opteron which is AMD64, so according to the guide above, -server is selected automatically. Please let me know if I've misunderstood this. We *definitely* want to be running hotspot! Regarding GC: we are generating GC logs for namenode, datanode, master and regionserver. We do see long GC from time to time. In fact, I played with the mslab option, but didn't find significant improvement. We've seen times on the order of a minute in these logs, and have found no way around it (spent countless days and nights experimenting with different GC parameters, mslab, different heap sizes, etc). -geoff -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jean-Daniel Cryans Sent: Monday, September 12, 2011 10:55 AM To: [email protected] Subject: Re: scanner deadlock? Two other thoughts to add on top of the rest: - You really should also consider using HotSpot instead of OpenJDK. - Depending on the size of your RS's heap, the number of concurrent scanners and if they are doing pre-caching, you may be just GCing like mad. Did you check that? J-D On Mon, Sep 12, 2011 at 10:42 AM, Stack <[email protected]> wrote: > What Eric says. > > Sun java can find deadlocks too, the dumb ones at least. > > And then Todd likes this for the same job: http://www.jcarder.org/ > > St.Ack
