Struct ReadReplicaPolicy 

pub struct ReadReplicaPolicy {
    pub pin_after_write: Duration,
    pub max_lag: Option<Duration>,
    pub health_probe_interval: Duration,
}

ReadReplicaConfig without the URLs: how replica routing behaves, separated from where the replicas are (#957).

The split exists because the two halves have different owners once tenant pools carry replicas. A tenant registration names its own replica URLs, the same way it names its own primary connection string — but the pin window, the staleness budget and the probe cadence are the operator’s policy, stamped onto every tenant pool by make_executor_factory, exactly as [database_tls] is (#801). A tenant that could send its own max_lag in a registration body would be choosing how stale its reads may be, against a server whose operator already decided.

Default carries the shipped defaults — a 5 s pin, no staleness budget, a 1 s probe cadence — so they live in one place rather than once per binary.

Fields

pin_after_write: Duration

See ReadReplicaConfig::pin_after_write.

max_lag: Option<Duration>

See ReadReplicaConfig::max_lag.

health_probe_interval: Duration

See ReadReplicaConfig::health_probe_interval.

Implementations

impl ReadReplicaPolicy

pub fn with_urls(&self, urls: Vec<String>) -> Option<ReadReplicaConfig>

Apply this policy to urls, or None when there are no replicas.

Returning None for an empty list is what keeps a pool site that has no replicas from constructing the one shape ReadReplicaConfig refuses to build.

Trait Implementations

impl Clone for ReadReplicaPolicy

fn clone(&self) -> ReadReplicaPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ReadReplicaPolicy

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

Formats the value using the given formatter.

impl Default for ReadReplicaPolicy

fn default() -> ReadReplicaPolicy

Returns the “default value” for a type.