Graylog server: Set the heap value in graylog-server, found at:
/etc/default/graylog-server for DEB-based packages
/etc/sysconfig/graylog-server for RPM-based packages
This file is a text file that you can generally open and update directly by adding the minimum and maximum heap size. It is recommended that you set the both values to be the same, so a typical setting might look like: