ServerWideClock

TODO: Add description

Installation

If available in Hex, the package can be installed by adding server_wide_clock to your list of dependencies in mix.exs:

def deps do
  [
    {:server_wide_clock, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/server_wide_clock.

Reading material

Server wide clocks paper

DottedDB paper

Implementation details

peers(i): Periodically, an anti-entropy protocol is started by a shard/vnode i. Unlike riak_core where each vnode is an erlang process, libring shards are just entries in the ring so the state machine processes here won't be aware which shard it is. A sensible sync period is ~100ms. We can randomly pick a shard that maps to the process and then undergo the usual anti entropy protocol as described in the paper. We can then set the sync period as 100ms/(shard_num). The peers of the shard are then the N-1 leading and trailing shards in the ring, where N is the replication number (separate from the sharding number, which ins libring is the weight).