Struct LayoutVersion

pub struct LayoutVersion {
    pub version: u64,
    pub roles: LwwMap<Uuid, NodeRoleV>,
    pub parameters: LayoutParameters,
    pub replication_factor: usize,
    pub partition_size: u64,
    pub node_id_vec: Vec<Uuid>,
    pub nongateway_node_count: usize,
    pub ring_assignment_data: Vec<CompactNodeType>,
}

A version of the layout of the cluster, i.e. the list of roles which are assigned to each cluster node

Fields

version: u64

The number of this version

roles: LwwMap<Uuid, NodeRoleV>

Roles assigned to nodes in this version

parameters: LayoutParameters

Parameters used to compute the assignment currently given by ring_assignment_data

replication_factor: usize

The number of replicas for each data partition

partition_size: u64

This attribute is only used to retain the previously computed partition size, to know to what extent does it change with the layout update.

node_id_vec: Vec<Uuid>

node_id_vec: a vector of node IDs with a role assigned in the system (this includes gateway nodes). The order here is different than the vec stored by roles, because:

1. non-gateway nodes are first so that they have lower numbers
2. nodes that don’t have a role are excluded (but they need to stay in the CRDT as tombstones)

nongateway_node_count: usize

number of non-gateway nodes, which are the first ids in node_id_vec

ring_assignment_data: Vec<CompactNodeType>

The assignation of data partitions to nodes, the values are indices in node_id_vec

Implementations

impl LayoutVersion

pub fn new(replication_factor: ReplicationFactor) -> Self

pub fn all_nodes(&self) -> &[Uuid]

Returns a list of IDs of nodes that have a role in this version of the cluster layout, including gateway nodes

pub fn nongateway_nodes(&self) -> &[Uuid]

Returns a list of IDs of nodes that have a storage capacity assigned in this version of the cluster layout

pub fn node_role(&self, node: &Uuid) -> Option<&NodeRole>

Returns the role of a node in the layout, if it has one

pub fn get_node_capacity(&self, uuid: &Uuid) -> Option<u64>

Returns the capacity of a node in the layout, if it has one

pub fn get_node_zone(&self, uuid: &Uuid) -> Option<&str>

Given a node uuids, this function returns the label of its zone if it has one

pub fn get_node_usage(&self, uuid: &Uuid) -> Result<usize, Error>

Returns the number of partitions associated to this node in the ring

pub fn partition_of(&self, position: &Hash) -> Partition

Get the partition in which data would fall on

pub fn partitions(&self) -> impl Iterator<Item = (Partition, Hash)> + '_

Get the list of partitions and the first hash of a partition key that would fall in it

pub fn nodes_of(&self, position: &Hash) -> impl Iterator<Item = Uuid> + '_

Return the n servers in which data for this hash should be replicated

pub fn replication_factor(&self) -> ReplicationFactor

pub fn read_quorum(&self, consistency_mode: ConsistencyMode) -> usize

pub fn write_quorum(&self, consistency_mode: ConsistencyMode) -> usize

pub fn check(&self) -> Result<(), String>

Check a cluster layout for internal consistency (assignment, roles, parameters, partition size) returns true if consistent, false if error

Trait Implementations

impl Clone for LayoutVersion

fn clone(&self) -> LayoutVersion

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LayoutVersion

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for LayoutVersion

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for LayoutVersion

fn eq(&self, other: &LayoutVersion) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for LayoutVersion

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for LayoutVersion