To increase the memory of Tomcat follow the instructions below:

1. edit the init scripts: nano /etc/init.d/tomcat8

2. change the line (JAVA_OPTS="-Djava.awt.headless=true -Xmx128M"
)

to (JAVA_OPTS="-Djava.awt.headless=true -Xmx512M -Xms64M -Dfile.encoding=UTF-8")

 

3. Restart tomcat8

/etc/init.d/tomcat8 restart