I have logstash 1.5.3 running on one of the server where the process details of it are as follows:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
13194 logstash 39 19 2181m 233m 12m S 1.3 4.0 1:09.79 java
The virtual memory as shown is 2181m which is very large. Although I have set the following parameters -Xmx256m -Xms256m -Xss2048k but it not helpful on this server which worked on other server.