When using jna the mlockall call will result in all pages locked in rss and thus reported there so you have either configured -Xms650M or you are running on a small box and the start script calculated it for you.
Also our experience shows that the jna call does not prevent swapping so the general advice is disable swap. If you had data in you server and did read requests some (partially) loaded sstables would show up in rss too. Also there is https://issues.apache.org/jira/browse/CASSANDRA-2868 On Jul 15, 2011, at 10:46 AM, Donna Li wrote: > All: > I download JNA jar and put it to cassandra lib directory. When restart > cassandra server, I found the physical memory highly increase. There is no > data saved in cassandra, why so much memory used by cassandra? How can I > decrease the memory usage by cassandra? My version is 0.7.6-2. > > > Before > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 11381 root 25 0 653m 57m 6272 S 0 5.7 0:02.33 java > > After > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 11130 root 25 0 653m 647m 9.9m S 0 64.2 0:03.57 java > > > Best Regards > Donna li
