Struct UpstreamPool 

pub struct UpstreamPool { /* private fields */ }

Upstream pool managing multiple backend servers

Implementations

impl UpstreamPool

pub async fn new(config: UpstreamConfig) -> SentinelResult<Self>

Create new upstream pool from configuration

pub async fn select_peer_with_metadata( &self, context: Option<&RequestContext>, ) -> SentinelResult<(HttpPeer, HashMap<String, String>)>

Select next upstream peer with selection metadata

Returns the selected peer along with optional metadata from the load balancer. The metadata can contain sticky session information that should be passed to the response filter.

pub async fn select_peer( &self, context: Option<&RequestContext>, ) -> SentinelResult<HttpPeer>

Select next upstream peer

pub async fn report_result(&self, target: &str, success: bool)

Report connection result for a target

On failure, the circuit breaker records the failure but the load balancer health status is only updated when the circuit breaker transitions to Open. This prevents a single connection error (e.g., a stale pooled connection reset) from permanently removing a target from the healthy pool.

pub async fn report_result_with_latency( &self, target: &str, success: bool, latency: Option<Duration>, )

Report request result with latency for adaptive load balancing

This method passes latency information to the load balancer for adaptive weight adjustment. It updates circuit breakers and health status. On failure, health is only marked down when the circuit breaker transitions to Open, preventing stale connection resets from permanently removing targets.

pub fn stats(&self) -> &PoolStats

Get pool statistics

pub fn id(&self) -> &UpstreamId

Get pool ID

pub fn target_count(&self) -> usize

Get target count

pub fn pool_config(&self) -> PoolConfigSnapshot

Get pool configuration (for metrics/debugging)

pub async fn has_healthy_targets(&self) -> bool

Check if the pool has any healthy targets.

Returns true if at least one target is healthy, false if all targets are unhealthy.

pub async fn select_shadow_target( &self, context: Option<&RequestContext>, ) -> SentinelResult<ShadowTarget>

Select a target for shadow traffic (returns URL components)

This is a simplified selection method for shadow requests that don’t need full HttpPeer setup. Returns the target URL scheme, address, and port.

pub fn is_tls_enabled(&self) -> bool

Check if TLS is enabled for this upstream

pub async fn shutdown(&self)

Shutdown the pool

Note: Pingora manages connection pooling internally, so we just log stats.