Problem/Bug Java error "Out of memory"

Hi, I have a little problem with my Bukkit server (ver. 1.8.3). Sometimes the server goes down with the error. What I must do to avoid crashing? Thanks for help.
I upload the error here - http://mineland.cz/hs_err_pid7959.log
Or here is the start of the error:
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 12288 bytes for committing reserved memory.
# Possible reasons:
# The system is out of physical RAM or swap space
# In 32 bit mode, the process size limit was hit
# Possible solutions:
# Reduce memory load on the system
# Increase physical memory or swap space
# Check if swap backing store is full
# Use 64 bit Java on a 64 bit OS
# Decrease Java heap size (-Xmx/-Xms)
# Decrease number of Java threads
# Decrease Java thread stack sizes (-Xss)
# Set larger code cache with -XX:ReservedCodeCacheSize=
# This output file may be truncated or incomplete.
#
# Out of Memory Error (os_linux.cpp:2671), pid=7959, tid=140043994445568
#
# JRE version: Java(TM) SE Runtime Environment (8.0_31-b13) (build 1.8.0_31-b13)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.31-b07 mixed mode linux-amd64 compressed oops)
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#


Sogo_CZ

 

@sogo_cz Well add this:

Code:

-XX:ReservedCodeCacheSize=

whatever size you want.

 

@nverdier ok thanks.. And what size you recommend if I have 2 GB ram to my server?