RaftEx.Server.Cluster (raft_ex v0.1.0)

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Helpers for managing the cluster membership map inside a server state.

The cluster is a %{server_id => peer_state} map stored under :cluster in the server state. This module keeps all mutation and query logic in one place so that RaftEx.Server stays focused on the Raft protocol.

Summary

Types

cluster()
peer_state()
server_id()

Functions

agreed_commit(indexes)

Return the highest index agreed upon by a quorum (majority).

get_membership(cluster, peer_id, uid, default)

Determine the membership role of id/uid within cluster.

get_peer(peer_id, cluster)

Get a single peer's state, returning nil if not found.

new(self, peers)

Build an initial cluster map from a list or map of peer identifiers.

peer_ids(self, cluster)

Return the peer ids excluding self.

peers(self, cluster)

Return all peers excluding self.

reset_peer_statuses(cluster)

Reset all peer statuses to :normal (used on becoming follower).

reset_query_indexes(cluster)

Reset query_index to 0 for all peers (used on term change).

update_peer(peer_id, update, cluster)

Update a peer by merging update into its current state.

voter_match_indexes(self, cluster, leader_last_written)

Collect the match indexes of all voter peers plus the leader's own last written index.

Types

cluster()

@type cluster() :: RaftEx.Types.cluster()

peer_state()

@type peer_state() :: RaftEx.Types.peer_state()

server_id()

@type server_id() :: RaftEx.Types.server_id()

Functions

agreed_commit(indexes)

@spec agreed_commit([RaftEx.Types.index()]) :: RaftEx.Types.index()

Return the highest index agreed upon by a quorum (majority).

get_membership(cluster, peer_id, uid, default)

@spec get_membership(
  cluster(),
  server_id(),
  RaftEx.Types.uid(),
  RaftEx.Types.membership()
) ::
  RaftEx.Types.membership()

Determine the membership role of id/uid within cluster.

get_peer(peer_id, cluster)

@spec get_peer(server_id(), cluster()) :: peer_state() | nil

Get a single peer's state, returning nil if not found.

new(self, peers)

@spec new(server_id(), [server_id()] | map()) :: cluster()

Build an initial cluster map from a list or map of peer identifiers.

peer_ids(self, cluster)

@spec peer_ids(server_id(), cluster()) :: [server_id()]

Return the peer ids excluding self.

peers(self, cluster)

@spec peers(server_id(), cluster()) :: cluster()

Return all peers excluding self.

reset_peer_statuses(cluster)

@spec reset_peer_statuses(cluster()) :: cluster()

Reset all peer statuses to :normal (used on becoming follower).

reset_query_indexes(cluster)

@spec reset_query_indexes(cluster()) :: cluster()

Reset query_index to 0 for all peers (used on term change).

update_peer(peer_id, update, cluster)

@spec update_peer(server_id(), map(), cluster()) :: cluster()

Update a peer by merging update into its current state.

voter_match_indexes(self, cluster, leader_last_written)

@spec voter_match_indexes(server_id(), cluster(), RaftEx.Types.index()) :: [
  RaftEx.Types.index()
]

Collect the match indexes of all voter peers plus the leader's own last written index.

Used to compute the new commit index.