Maybe it's not a case of heap size? Heap size 4gb, but Play Application can still use more.
Heap Configuration:
MinHeapFreeRatio = 0
MaxHeapFreeRatio = 100
MaxHeapSize =
4244635648 (4048.0MB)
NewSize = 1414529024 (1349.0MB)
MaxNewSize = 1414529024 (1349.0MB)
OldSize = 2830106624 (2699.0MB)
NewRatio = 2
SurvivorRatio = 8
MetaspaceSize = 21807104 (20.796875MB)
CompressedClassSpaceSize = 1073741824 (1024.0MB)
MaxMetaspaceSize = 17592186044415 MB
G1HeapRegionSize = 0 (0.0MB)
Heap Usage:
PS Young Generation
Eden Space:
capacity = 552075264 (526.5MB)
used = 166902448 (159.1705780029297MB)
free = 385172816 (367.3294219970703MB)
30.231828680518458% used
From Space:
capacity = 438304768 (418.0MB)
used = 0 (0.0MB)
free = 438304768 (418.0MB)
0.0% used
To Space:
capacity = 424148992 (404.5MB)
used = 0 (0.0MB)
free = 424148992 (404.5MB)
0.0% used
PS Old Generation
capacity = 2830106624 (2699.0MB)
used = 2829590112 (2698.5074157714844MB)
free = 516512 (0.492584228515625MB)
99.9817493801958% used