On 01/04/2014 10:04 AM, Ertio Lew wrote:
I run a development Cassandra single node server on both ubuntu &
windows 8 on my dual boot 4GB(RAM) machine.
I see that cassandra runs fine under windows without any crashes or OOMs
however in ubuntu on same machine, it always gives an OOM message
*$* *sudo service cassandra start*
xss = -ea -javaagent:/usr/share/cassandra/lib/jamm-0.2.5.jar
-XX:+UseThreadPriorities -XX:ThreadPriorityPolicy=42 -Xms4G -Xmx4G
-Xmn800M -XX:+HeapDumpOnOutOfMemoryError -Xss256k
The above is not a system OOM error, but is the console output of the
JVM options being passed at startup, including one to dump the heap if
an OOM does occur.
Here is the memory usage for empty cassandra server in ubuntu.
*(PID)1169 (USER)cassandr (PR)20 (NI)0 (VIRT)2639m (RES)1.3g
(SHR)17m S (%CPU)1 (%MEMORY)33.9 (TIME)0:53.80 (COMMAND)java*
The memory usage however while running under windows is very low
relative to this.
Windows and Linux report memory usage very differently. Functional
benchmarks would be much better things to look at for comparing the
performance on different operating systems. Memory usage patterns under
long-running load tests, disk I/O, etc. might be far more interesting
than simply starting the service and looking at `free` and
$WINDOWS_EQUIVALENT. Have a look at cassandra-stress.
What is the reason behind this ?
Perhaps http://www.linuxatemyram.com/ ?
Also how can I prevent these OOMs within Ubuntu? I am running Datastax's
DSC version 2.0.3.
Again, what you posted aren't OOMs, but if you are seeing the OS killing
your cassandra process, then you have some tuning to do. If you need
help with tuning, post logs somewhere (cassandra and OS syslog).
--
Kind regards,
Michael
