Struct ConnectionLimiter 

pub struct ConnectionLimiter { /* private fields */ }

Live-connection accounting for one node’s listeners. A clone shares the same counters, so every accept loop and every ConnectionGuard account against one set of totals.

Implementations

impl ConnectionLimiter

pub fn new(max_connections: usize, max_connections_per_ip: usize) -> Self

A limiter for a node started with max_connections and max_connections_per_ip.

pub const fn limits(&self) -> ConnectionLimits

The caps this limiter was started with.

pub fn quotas( &self, image: &MetadataImage, node_id: NodeId, listener: &str, ) -> ConnectionQuotas

The quotas in force on listener of node_id as of image. A value Kafka would refuse leaves the listener’s previous value in force. A new max.connections.per.ip.overrides set that names a host is resolved in the background, so this never waits on DNS. It must be called within a Tokio runtime.

pub fn creation_delay( &self, listener: AcceptingListener<'_>, quotas: &ConnectionQuotas, now: Instant, max_delay: Duration, ) -> Duration

Record a new connection on listener at now against the creation rates of quotas, and return how long the acceptor waits before it takes the connection, at most max_delay (quota.window.size.seconds). Kafka’s acceptor waits the throttle out and then accepts.

pub fn refund_creation( &self, listener: AcceptingListener<'_>, quotas: &ConnectionQuotas, )

Take back a connection Self::creation_delay recorded, for one the peer’s ip quota throttles, as Kafka’s updateListenerMetrics un-records it from the broker-wide and listener rates.

pub fn try_acquire_within( &self, ip: IpAddr, listener: AcceptingListener<'_>, quotas: &ConnectionQuotas, ) -> Result<ConnectionGuard, ConnectionLimit>

Try to reserve a slot for a connection from ip on listener under quotas, which the caller resolves per accept. On success returns a ConnectionGuard that releases the slot on drop. Lowering a cap closes no connection that is already counted, as in Kafka’s ConnectionQuotas.

The checks run in Kafka’s order: the listener’s cap, then, unless the listener is protected, the broker-wide cap, then the cap of the address.

Errors

Returns the ConnectionLimit that refused the connection, and reserves nothing.

pub fn total(&self) -> usize

Diagnostic accessor: current live-connection count across listeners.

Trait Implementations

impl Clone for ConnectionLimiter

fn clone(&self) -> ConnectionLimiter

Returns a duplicate of the value.

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

Performs copy-assignment from source.