Struct ZoneConfig 

pub struct ZoneConfig { /* private fields */ }

Zone configuration for CockroachDB

This struct represents zone configuration options for databases, tables, or indexes. Zone configurations control how CockroachDB distributes and replicates data across your cluster.

Fields

• num_replicas: Number of copies of data to maintain (default: 3)
• constraints: Placement rules for replicas (required/prohibited locations)
• lease_preferences: Preferences for which replicas serve reads

Constraint Format

Constraints use a + (required) or - (prohibited) prefix:

• +region=us-east-1: Replicas MUST be in us-east-1
• -region=us-west-1: Replicas MUST NOT be in us-west-1
• +zone=a: Replicas MUST be in zone ‘a’

Lease Preferences Format

Lease preferences determine which replica serves reads. They use the same format as constraints but represent priorities rather than requirements.

Examples

Basic Configuration

use reinhardt_query::types::ZoneConfig;

let zone = ZoneConfig::new()
    .num_replicas(3)
    .add_constraint("+region=us-east-1")
    .add_lease_preference("+region=us-east-1");

Multi-Region High Availability

use reinhardt_query::types::ZoneConfig;

// 5 replicas across 3 regions
let zone = ZoneConfig::new()
    .num_replicas(5)
    .add_constraint("+region=us-east-1")
    .add_constraint("+region=us-west-1")
    .add_constraint("+region=eu-west-1")
    .add_lease_preference("+region=us-east-1"); // Prefer us-east-1 for reads

Exclude Specific Zones

use reinhardt_query::types::ZoneConfig;

// Avoid certain zones for compliance
let zone = ZoneConfig::new()
    .num_replicas(3)
    .add_constraint("+region=us-east-1")
    .add_constraint("-zone=deprecated"); // Exclude deprecated zones

Tiered Read Preferences

use reinhardt_query::types::ZoneConfig;

// Primary: us-east-1, Secondary: us-west-1
let zone = ZoneConfig::new()
    .num_replicas(3)
    .add_lease_preference("+region=us-east-1")
    .add_lease_preference("+region=us-west-1"); // Fallback if us-east-1 unavailable

Implementations

impl ZoneConfig

pub fn new() -> Self

Create a new zone configuration

pub fn num_replicas(self, replicas: i32) -> Self

Set the number of replicas

Examples

use reinhardt_query::types::ZoneConfig;

let zone = ZoneConfig::new().num_replicas(3);

pub fn add_constraint<S: Into<String>>(self, constraint: S) -> Self

Add a constraint

Examples

use reinhardt_query::types::ZoneConfig;

let zone = ZoneConfig::new()
    .add_constraint("+region=us-east-1")
    .add_constraint("+zone=a");

pub fn add_lease_preference<S: Into<String>>(self, preference: S) -> Self

Add a lease preference

Examples

use reinhardt_query::types::ZoneConfig;

let zone = ZoneConfig::new()
    .add_lease_preference("+region=us-east-1");

Trait Implementations

impl Clone for ZoneConfig

fn clone(&self) -> ZoneConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ZoneConfig

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

Formats the value using the given formatter.

impl Default for ZoneConfig

fn default() -> ZoneConfig

Returns the “default value” for a type.