Have a look at either Eclipse Memory Analyser (they have a standalone version of the memory analyser) or YourKit Java Profiler (commercial, but with evaluation license). I successfully load and browse heap bigger than the available memory on the system.
Regards, Benoit 2010/4/3 Weijun Li <weiju...@gmail.com>: > Thank you Benoit. I did a search but couldn't find any that you mentioned. > Both jhat and netbean load entire map file int memory. Do you know the name > of the tools that requires less memory to view map file? > Thanks, > -Weijun > > On Sat, Apr 3, 2010 at 12:55 AM, Benoit Perroud <ben...@noisette.ch> wrote: >> >> It exists other tools than jhat to browse a heap dump, which stream >> the heap dump instead of loading it full in memory like jhat do. >> >> Kind regards, >> >> Benoit. >> >> 2010/4/3 Weijun Li <weiju...@gmail.com>: >> > I'm running a test to write 30 million columns (700bytes each) to >> > Cassandra: >> > the process ran smoothly for about 20mil then the heap usage suddenly >> > jumped >> > from 2GB to 3GB which is the up limit of JVM, --from this point >> > Cassandra >> > will freeze for long time (terrible latency, no response to nodetool >> > that I >> > have to stop the import client ) before it comes back to normal . It's a >> > single node cluster with JVM maximum heap size of 3GB. So what could >> > cause >> > this spike? What kind of tool can I use to find out what are the objects >> > that are filling the additional 1GB heap? I did a heap dump but could >> > get >> > jhat to work to browse the dumped file. >> > >> > Thanks, >> > >> > -Weijun >> > > >
