This takes advantage of go-ds-badger "auto-gc" feature.
It will run a GC cycle made of multiple GC rounds (until it cannot GC more)
automatically. The behaviour is enabled by default in the configuration and
can be disabled by setting "gc_interval" to "0m". Hopefully this prevents
badger datastores from growing crazy.
Badger can take 1000x the amount of needed space if not GC'ed or compacted
(#1320), even for non heavy usage. Cluster has no provisions to run datastore
GC operations and while they could be added, they are not ensured to
help. Improvements on Badger v3 might help but would still need to GC
explicitally.
Cluster was however designed to support any go-datastore as backend.
This commit adds LevelDB support. LevelDB go-datastore wrapper is mature, does
not need GC and should work well for most cluster usecases, which are not
overly demanding.
A new `--datastore` flag has been added on init. The store backend is selected
based on the value in the configuration, similar to how raft/crdt is. The
default is set to leveldb. From now on it should be easier to add additional
backends, i.e. badgerv3.
For simplicity, I haven't exposed the entire
badger config. Also, due to go default values and
the badger implementation, I have had to extract the
two loading mode config values so we can determine
whether it has actually has been set by the user in
the json config file.
License: MIT
Signed-off-by: Adrian Lanzafame <adrianlanzafame92@gmail.com>
