by defaul tomcat7 inside Docker image can use up to 3G memory

Docker/Dockerfile

@@ -45,6 +45,7 @@ ADD policy-rc.d /tmp/policy-rc.d
 
 RUN apt-get update
 
+RUN sed -i "/JAVA_OPTS=\"-Djava.awt.headless=true -Xmx128m -XX:+UseConcMarkSweepGC\"/c\JAVA_OPTS=\"-Djava.awt.headless=true -Xmx3096m -XX:+UseConcMarkSweepGC\"" /etc/default/tomcat7
 
 #when we install minerva allow to start services, so everything can be installed properly
 #but we need to disable tomcat7 because tomcat7 requires SYS_PTRACE and we cannot start it: