Struct scylla::transport::locator::ReplicaLocator

pub struct ReplicaLocator { /* private fields */ }

ReplicaLocator provides a way to find the set of owning nodes for a given (token, replication strategy, table) tuple. It does so by either using the precomputed token ranges, or doing the computation on the fly (precomputation is configurable).

Implementations

impl ReplicaLocator

pub fn replicas_for_token<'a>( &'a self, token: Token, strategy: &'a Strategy, datacenter: Option<&'a str>, table_spec: &TableSpec<'_>, ) -> ReplicaSet<'a>

Returns a set of nodes that are considered to be replicas for a given token, strategy and table. If the datacenter parameter is set, the returned ReplicaSet is limited only to replicas from that datacenter. If a specified datacenter name does not correspond to a valid datacenter, an empty set will be returned.

Supported replication strategies: SimpleStrategy, ‘NetworkTopologyStrategy’, ‘LocalStrategy’. If other is specified, it is treated as the SimpleStrategy with replication factor equal to 1.

If a provided replication strategy did not appear in precompute_replica_sets_for parameter of Self::new, invocation of this function will trigger a computation of the desired replica set (the computation might be delegated in time and start upon interaction with the returned ReplicaSet).

If the requested table uses Tablets, then a separate code path is taken, which ignores replication strategies and only uses tablet information stored in ReplicaLocator. If we don’t have info about the tablet that owns the given token, empty set will be returned.

pub fn ring(&self) -> &TokenRing<Arc<Node>>

Gives access to the token ring, based on which all token ranges/replica sets are computed.

pub fn unique_nodes_in_global_ring(&self) -> &[Arc<Node>]

Gives a list of all nodes in the token ring.

pub fn datacenter_names(&self) -> &[String]

Gives a list of all known datacenters.

pub fn unique_nodes_in_datacenter_ring<'a>( &'a self, datacenter_name: &str, ) -> Option<&'a [Arc<Node>]>

Gives a list of all nodes in a specified datacenter ring (which is created by filtering the original ring to only contain nodes living in the specified datacenter).

Trait Implementations

impl Clone for ReplicaLocator

fn clone(&self) -> ReplicaLocator

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ReplicaLocator

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

Formats the value using the given formatter.