Alphanet stability
A bunch of patches for increasing the alphanet stability.
The current alphanet suffers a 'faucet war', i.e. some people are injecting a lot of 'faucet' operations, thus increasing the number of rolls far higher than the expected number of rolls in the mainnet. To mitigate this behavious, this MR:
- limits at 5 the number of allowed faucet operation in a block ;
- limits the number of roll at 100,000 by dynamically increasing the roll value ;
- implements an experimental LevelDB backend for irmin.
Edited by Grégoire Henry