      <!-- the system will enter into page mode once you hit this limit.
           This is an estimate in bytes of how much the messages are using in memory

            The system will use half of the available memory (-Xmx) by default for the global-max-size.
            You may specify a different value here if you need to customize it to your needs.

            <global-max-size>100Mb</global-max-size>

      -->
