Memory leak in 7.3.4

We have a streaming application that processes JSON messages. Our system has been mostly stable running PyPy2.7 6.0 for a couple of years.

Recently we tried upgrading to 7.3.4 and saw our processes leak memory until the container was killed. This happened with both PyPy2.7 7.3.4 and PyPy3.7 7.3.4. The only difference was the cpu usage with PyPy3.7 was almost double. :(

My question is could this be from the new JSON parser introduced in 7.2? According to https://morepypy.blogspot.com/2019/10/pypys-new-json-parser.html, the parser now caches values not just keys. Is there anyway to disable the value caching? Or other things we can try?

Thanks,

Brad.