The size of the client heap is 1.4G while 94% related to FIFO. See below:
com.gigaspaces.events.fifo.BlockedOrderedQueue" loaded by "sun.misc.Launcher$AppClassLoader @ 0x800e3aa8" occupies 1,296,420,232 (94.33%) bytes. The memory is accumulated in one instance of "java.util.concurrent.ConcurrentHashMap$Node" loaded by "<system class loader>".
The heap dump can be found here: