You can track allocations using this: Profiling · The Julia Language
Maybe that can help, if you leave the process running for a while (or different spans of time), and check where allocations are occurring.
Here I give an example (because the manual is not as direct): Disabling allocations - #10 by lmiq
Depending on your problem, you could check the memory usage and call the GC (I have used this before solving some problems in a parallel code, afterwards it was not useful anymore): https://discourse.julialang.org/t/garbage-collector-behaviour-when-memory-is-almost-full