Module lb 

Available on crate feature dns only.

DNS-based client-side load balancer.

DnsLoadBalancer resolves a request’s target domain, caches the result, refreshes it in the background, and selects one resolved IP per request via a DnsIpPicker strategy. The selected endpoint is published on the request as a ConnectorTarget extension so a downstream connectors (tcp, pool…) connects straight to that IP, the original authority stays intact (needed for things like TLS sni).

Example use case: rotating GPRC requests between different IPs of a headless service.

Structs

DnsLoadBalancer

Service that pins each request to an IP picked from the resolved DNS entries

DnsLoadBalancerConfig

DNS loadbalancer config used by DnsLoadBalancerLayer and DnsLoadBalancer.

DnsLoadBalancerLayer

Layer producing a DnsLoadBalancer service from a DnsLoadBalancerConfig.

HostResolution

The data a DnsIpPicker sees for a single host

RandomPicker

Random IP picker

RoundRobinPicker

Round-robin IP picker

Constants

DEFAULT_LB_EVICT_AFTER_IDLE

DEFAULT_LB_EVICT_AFTER_STALE

DEFAULT_LB_MAX_ENTRIES

DEFAULT_LB_REFRESH_AFTER

Traits

DnsIpPicker

Strategy that selects one IpAddr from a HostResolution.