Struct RoutingTable 

pub struct RoutingTable { /* private fields */ }

Maps vShards to Raft groups and Raft groups to nodes.

The 1024 vShards are divided into distinct Raft Groups (e.g., vShards 0-63 managed by Raft Group 1 across Nodes A, B, and C).

This table is the authoritative routing source. It is updated atomically via Raft state machine when:

• A shard migration completes (Phase 3 atomic cut-over)
• A Raft group membership changes
• A node joins or decommissions

Implementations

impl RoutingTable

pub fn uniform( num_groups: u64, nodes: &[u64], replication_factor: usize, ) -> Self

Create a routing table with uniform distribution of vShards across data groups.

num_groups is the number of data Raft groups. vShards are distributed round-robin across groups 1..=num_groups. Group 0 is the metadata group and is always included in group_members but is never assigned any vShards — it is accessed only via propose_to_metadata_group, never via propose(vshard_id, data).

Each data group initially contains replication_factor nodes from nodes. The metadata group (0) receives the same membership as the first data group.

pub fn group_for_vshard(&self, vshard_id: u32) -> Result<u64>

Look up which Raft group owns a vShard.

pub fn leader_for_vshard(&self, vshard_id: u32) -> Result<u64>

Look up the leader node for a vShard.

pub fn group_info(&self, group_id: u64) -> Option<&GroupInfo>

Get group info.

pub fn set_leader(&mut self, group_id: u64, leader: u64)

Update the leader for a Raft group.

pub fn reassign_vshard(&mut self, vshard_id: u32, new_group_id: u64)

Atomically reassign a vShard to a different Raft group. Used during Phase 3 (atomic cut-over) of shard migration.

pub fn vshards_for_group(&self, group_id: u64) -> Vec<u32>

All vShards assigned to a given group.

pub fn num_groups(&self) -> usize

Number of Raft groups.

pub fn group_ids(&self) -> Vec<u64>

All group IDs.

pub fn set_group_members(&mut self, group_id: u64, members: Vec<u64>)

Update the voting members of a Raft group (for membership changes).

pub fn remove_group_member(&mut self, group_id: u64, node_id: u64) -> bool

Remove a node from a group’s voter and learner lists. If the removed node was the current leader hint, the hint is cleared so the next query drives a fresh discovery. Returns true if the group existed and anything was actually removed.

The caller is responsible for safety: dropping below the configured replication factor must be gated by decommission::safety::check_can_decommission.

pub fn set_group_learners(&mut self, group_id: u64, learners: Vec<u64>)

Update the learner list for a Raft group.

pub fn add_group_learner(&mut self, group_id: u64, peer: u64)

Add a learner to a group if not already present. No-op if the peer is already a voter or a learner.

pub fn promote_group_learner(&mut self, group_id: u64, peer: u64) -> bool

Promote a learner to a voter within a group. Returns true if the learner was found and promoted.

pub fn vshard_to_group(&self) -> &[u64]

Access the vshard-to-group mapping (for persistence / wire transfer).

pub fn group_members(&self) -> &HashMap<u64, GroupInfo>

Access all group members (for persistence / wire transfer).

pub fn from_parts( vshard_to_group: Vec<u64>, group_members: HashMap<u64, GroupInfo>, ) -> Self

Reconstruct a RoutingTable from persisted data.

Trait Implementations

impl Clone for RoutingTable

fn clone(&self) -> RoutingTable

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RoutingTable

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for RoutingTable

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'__msgpack_de> FromMessagePack<'__msgpack_de> for RoutingTable

fn read<R: Read<'__msgpack_de>>(reader: &mut R) -> Result<Self, Error>

where Self: Sized,

Reads the MessagePack representation of this value from the provided reader.

impl Serialize for RoutingTable

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl ToMessagePack for RoutingTable

fn write<W: Write>(&self, writer: &mut W) -> Result<(), Error>

Writes the MessagePack representation of this value into the provided writer.