.
It works when I take snap of just web app restart, but if I do some operations and then do kill -3 it gives
Dumping Java heap ...HPROF ERROR: Mis-match on instance size in instance dump [../../../src/share/demo/jvmti/hprof/hprof_io.c:2602]
HPROF TERMINATED PROCESS
Control-\ dump requests have the same effect. This is running b74 fastdebug
bits on my office machine (Ultra-80, Solaris 9). The full XtermLog is attached
as XtermLog.c++filtered

% java -showversion -agentlib:hprof=heap=all,format=b,verbose=y -jar \
      $JAVA_HOME/demo/jfc/Java2D/Java2Demo.jar
java version "1.6.0-beta2-fastdebug"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-beta2-fastdebug-b74)
Java HotSpot(TM) Client VM (build 1.6.0-beta2-fastdebug-b74-debug, mixed mode)

^\2006-03-09 16:36:42
Full thread dump Java HotSpot(TM) Client VM (1.6.0-beta2-fastdebug-b74-debug mixed mode):

[...snip...]

Dumping Java heap ...HPROF ERROR: Mis-match on instance size in instance dump [hprof_io.c:1753]
HPROF TERMINATED PROCESS
HPROF DUMPING CORE
Abort (core dumped)

Dumping Java heap ...HPROF ERROR: Mis-match on instance size in instance dump [hprof_io.c:1753]
HPROF TERMINATED PROCESS
HPROF DUMPING CORE
Abort (core dumped)

% jstack -m -l `which java` core
[...]
----------------- t@6 -----------------
0xff29e71c _lwp_kill + 0x8
0xff2369e8 abort + 0x100
0xfefa767c error_abort + 0x34
0xfefa77b8 terminate_everything + 0x70
0xfefa7a64 error_handler + 0xdc
0xfefb2d14 io_heap_instance_dump + 0x120
0xfefb7f84 dump_instance + 0x7ac
0xfefb8380 reference_dump_instance + 0xc
0xfefb6264 dump_instance_references + 0x4c
0xfefbbef8 table_walk_items + 0x13c
0xfefb66f4 object_reference_dump + 0x44
0xfefba058 site_heapdump + 0x130
0xfefaad60 dump_all_data + 0x9c
0xfefaca98 cbDataDumpRequest + 0x148
0xfe0f25a0 void JvmtiExport::post_data_dump() + 0xa14
0xfe26dde4 void signal_thread_entry(JavaThread*,Thread*) + 0x338
0xfe40c7c4 void JavaThread::thread_main_inner() + 0x230
0xfe40c574 void JavaThread::run() + 0x534
0xfe275f18 java_start + 0x174
0xff3857b4 _lwp_start
Locked ownable synchronizers:
    - None