Struct PoolConfig 

pub struct PoolConfig {

    pub endpoint: String,
    pub database: String,
    pub create_mode: CreateMode,
    pub user: Option<String>,
    pub password: Option<String>,
    pub max_size: usize,
    pub health_check: bool,
    pub recycle: RecycleStrategy,
    pub wait_timeout: Option<Duration>,
    pub create_timeout: Option<Duration>,
    pub recycle_timeout: Option<Duration>,
    pub max_lifetime: Option<Duration>,
    pub idle_timeout: Option<Duration>,
    pub min_idle: Option<u32>,
    pub after_connect: Option<AfterConnectHook>,
    pub before_acquire: Option<BeforeAcquireHook>,
}

Configuration for the async connection pool.

Fields

endpoint: String

Server endpoint (e.g., “localhost:7483” or “http://localhost:7484”)

database: String

Database path

create_mode: CreateMode

Database creation mode (only used for first connection)

user: Option<String>

Optional username for authentication

password: Option<String>

Optional password for authentication

max_size: usize

Maximum number of connections in the pool

health_check: bool

If false, skip the per-checkout health probe. Retained for backwards compatibility — it is kept in sync with recycle by the health_check and recycle builders. Prefer setting recycle directly.

recycle: RecycleStrategy

Strategy used to validate connections on checkout. Defaults to RecycleStrategy::SelectOne.

wait_timeout: Option<Duration>

Maximum time to wait for a slot to become available on get. None waits indefinitely (the default).

create_timeout: Option<Duration>

Maximum time to wait for a new connection to be created. None disables the cap (the default).

recycle_timeout: Option<Duration>

Maximum time to wait for the recycle probe to complete. None disables the cap (the default).

max_lifetime: Option<Duration>

Maximum lifetime of a physical connection before it is retired at checkout, regardless of health. None disables the cap (the default).

idle_timeout: Option<Duration>

Maximum time a connection may sit idle before it is retired at checkout. None disables the cap (the default).

min_idle: Option<u32>

Minimum number of idle connections to keep warm (not eagerly created; used to bias eviction decisions). None means no floor (the default).

after_connect: Option<AfterConnectHook>

Optional hook run on every newly-opened connection (see AfterConnectHook).

before_acquire: Option<BeforeAcquireHook>

Optional hook run on every checkout (see BeforeAcquireHook).

Implementations

impl PoolConfig

pub fn new(endpoint: impl Into<String>, database: impl Into<String>) -> Self

Creates a new pool configuration.

All optional knobs default to None/disabled and recycle defaults to RecycleStrategy::SelectOne, so a config that sets only endpoint/database/max_size behaves identically to prior versions.

pub fn create_mode(self, mode: CreateMode) -> Self

Sets the database creation mode.

pub fn auth(self, user: impl Into<String>, password: impl Into<String>) -> Self

Sets authentication credentials.

pub fn max_size(self, size: usize) -> Self

Sets the maximum pool size.

pub fn health_check(self, enabled: bool) -> Self

Enables or disables the per-checkout health probe.

Backwards-compatible shorthand for recycle: true selects RecycleStrategy::SelectOne, false selects RecycleStrategy::None. Prefer recycle for finer control.

pub fn recycle(self, strategy: RecycleStrategy) -> Self

Sets the per-checkout recycle strategy. Keeps the legacy health_check flag in sync (false iff the strategy is RecycleStrategy::None).

pub fn wait_timeout(self, timeout: Option<Duration>) -> Self

Sets the maximum time to wait for an available slot on get.

pub fn create_timeout(self, timeout: Option<Duration>) -> Self

Sets the maximum time to wait for a new connection to be created.

pub fn recycle_timeout(self, timeout: Option<Duration>) -> Self

Sets the maximum time to wait for the recycle probe to complete.

pub fn max_lifetime(self, lifetime: Option<Duration>) -> Self

Sets the maximum lifetime of a physical connection.

pub fn idle_timeout(self, timeout: Option<Duration>) -> Self

Sets the maximum idle time before a connection is retired at checkout.

pub fn min_idle(self, min_idle: Option<u32>) -> Self

Sets the minimum number of idle connections to keep warm.

pub fn after_connect<F>(self, hook: F) -> Self

where F: Fn(&AsyncConnection) -> HookFuture<'_> + Send + Sync + 'static,

Installs a hook that runs on every newly-opened connection.

Use this to apply session-level setup (e.g. SET search_path, install prepared statements). The hook is called once per physical connection, not per checkout.

pub fn before_acquire<F>(self, hook: F) -> Self

where F: Fn(&AsyncConnection) -> HookFuture<'_> + Send + Sync + 'static,

Installs a hook that runs on every connection checkout, before the connection is handed to the caller.

Returning Err from the hook evicts the connection from the pool; the caller’s pool.get() then retries with another connection or builds a new one. Use this for per-acquire health checks beyond the configured recycle probe (e.g. validating session state).

Trait Implementations

impl Clone for PoolConfig

fn clone(&self) -> PoolConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PoolConfig

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

Formats the value using the given formatter.