memory creeping up

[ninjaahhh]

memory is still creeping up on my 4g-mem machine. after running for the 3~4 days (after the keccak fix) the memory usage went from ~1.2g to ~3g.

master: ~700m
slave 1: ~1.1g
slave 2: ~1.1g

[qcdll]

it may be worthwhile to keep a multi-day cluster of python3 with #254

[ninjaahhh]

agree with @qcdll. let's keep track of those machines

[qcdll]

here is a slave left overnight:
https://gist.github.com/qcdll/fe22b6ab2c143b3bf8f13e8a3f156f6c
the log takes snapshot every 1 min and report differences, there is some steady increase from core.py which seems to relate to deserialization (mem allocated on those lines were never freed)

[qcdll]

top mem usage by lineno and some traceback
this was obtained from a slave that ran 1+ days
https://gist.github.com/qcdll/8a6c1ce4fd5b675162fb6dfb1a0d7fe7

[qcdll]

based on analysis above, adding new counts in #254 and will be launching clusters with python3 and #254 for testnet 23

also as @ninjaahhh suggests will also be running profiling with mining enabled