We saw a crash in JDK 6u16. We also saw same core dumps in 6u14.

$/usr/bin/gdb ../../lib/webservd core.30729
Core was generated by `webservd -d /export/home/meena/iplanet/ias/server/work/B1/Linux2.6_64_DBG.OBJ/h'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /export/home/meena/iplanet/ias/server/work/B1/Linux2.6_64_DBG.OBJ/lib/liblibdbm.so...done.
Loaded symbols for /export/home/meena/iplanet/ias/server/work/B1/Linux2.6_64_DBG.OBJ/lib/liblibdbm.so
..
Loaded symbols for /lib64/libnss_dns.so.2
#0 0x0000002a9c6511c1 in PhaseIdealLoop::build_loop_late_post ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
(gdb) where
#0 0x0000002a9c6511c1 in PhaseIdealLoop::build_loop_late_post ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#1 0x0000002a9c650e86 in PhaseIdealLoop::build_loop_late ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#2 0x0000002a9c64e30d in PhaseIdealLoop::PhaseIdealLoop ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#3 0x0000002a9c3ae10b in Compile::Optimize ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#4 0x0000002a9c3ab313 in Compile::Compile ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#5 0x0000002a9c33fdee in C2Compiler::compile_method ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#6 0x0000002a9c3b4028 in CompileBroker::invoke_compiler_on_method ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#7 0x0000002a9c3b39c6 in CompileBroker::compiler_thread_loop ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#8 0x0000002a9c7af1e9 in compiler_thread_entry ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#9 0x0000002a9c7a8cb1 in JavaThread::run ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#10 0x0000002a9c6c426f in java_start ()
   from /export/home/meena/iplanet/ias/server/src/cpp/iws/netsite/tests/run/../../../../../../../server/external/jdk6/Linux2.6_64_DBG.OBJ/jre/lib/amd64/server/libjvm.so
#11 0x0000003fdcb06137 in start_thread () from /lib64/tls/libpthread.so.0
#12 0x0000003fdc2c7533 in clone () from /lib64/tls/libc.so.6
(gdb)


This is very critical as web server can not ship with core dumps.