Struct LaunchConfig 

#[non_exhaustive]
pub struct LaunchConfig {

    pub drain_budget: Duration,
    pub request_timeout: Duration,
    pub max_in_flight: usize,
    pub max_body_bytes: usize,
    pub cache_max_entries: usize,
    pub cache_sweep_interval: Duration,
    pub ws_drain_deadline: Duration,
    pub cors: Option<CorsConfig>,
    pub shutdown_trigger: Option<Arc<Notify>>,
    pub expose_docs: bool,
    pub ws_outbound_buffer: usize,
    pub ws_max_connections: usize,
    pub ws_ping_interval: Duration,
    pub adaptive_shed_target: Duration,
    pub ws_idle_timeout: Duration,
}

Tunables for the launch contract. Start from Default and adjust:

App::launch_configured::<AppModule>(addr, info, plugins, LaunchConfig {
    request_timeout: Duration::from_secs(10),
    max_in_flight: 4_096,
    cors: Some(CorsConfig::for_origins(["https://app.example.com"])),
    ..Default::default()
}).await

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

drain_budget: Duration

Per-plugin budget for on_shutdown / start-failure rollback (and the concurrent on_draining notification). A plugin exceeding it is skipped with a logged warning — it can never wedge the process. Default 5s.

request_timeout: Duration

Process-wide request deadline. Routes without #[Timeout] are cancelled (worker freed) and answered 504 past this. ZERO disables. Default 30s.

max_in_flight: usize

Hard cap on concurrent in-flight requests — beyond it requests are shed with 503 + Retry-After before any body is read (one atomic counter, no locks). 0 = unlimited. Default 0.

max_body_bytes: usize

Request body cap for every entry point. Default 8 MiB.

cache_max_entries: usize

Ceiling on #[CacheTTL] store entries — the key includes the query string, so an unbounded store is a memory-DoS vector. Default 10 000.

cache_sweep_interval: Duration

How often the cache sweeper reclaims expired entries. Default 30s.

ws_drain_deadline: Duration

After a shutdown signal, WebSocket clients get this long to finish before the server sends Close frames — otherwise live sockets keep the HTTP drain (and therefore plugin on_shutdown) waiting until the supervisor SIGKILLs. Default 10s.

cors: Option<CorsConfig>

CORS policy. None (default) mounts no CORS layer at all.

shutdown_trigger: Option<Arc<Notify>>

Programmatic shutdown trigger — notifying it behaves exactly like receiving SIGTERM (drain flag, WS deadline, plugin hooks). Wired by testing::TestServer::shutdown; production should keep None and use real signals.

expose_docs: bool

Mount /docs (Swagger UI) and /openapi.json. Default true; disable in hardened deployments that publish the spec elsewhere.

ws_outbound_buffer: usize

Per-socket outbound queue depth — the slow-client memory ceiling; a client that can’t drain it is evicted. Default 256.

ws_max_connections: usize

Hard cap on concurrent WebSocket connections across all gateways; beyond it upgrades get 503 before any socket exists. 0 = unlimited. Default 0.

ws_ping_interval: Duration

Server→client Ping cadence; pongs feed the idle sweeper. ZERO disables. Default 20s.

adaptive_shed_target: Duration

Adaptive latency shedding: when the EWMA of request latency exceeds this target, a pressure-proportional slice of traffic is shed with 503 (capped at 90% so the EWMA can recover). ZERO disables. Default ZERO (opt-in).

ws_idle_timeout: Duration

Reap sockets with no inbound activity for this long — dead TCP links (NAT drops) never send Close and would linger forever. ZERO disables. Default 60s.

Implementations

impl LaunchConfig

pub fn drain_budget(self, v: Duration) -> Self

pub fn request_timeout(self, v: Duration) -> Self

pub fn max_in_flight(self, v: usize) -> Self

pub fn max_body_bytes(self, v: usize) -> Self

pub fn cache_max_entries(self, v: usize) -> Self

pub fn cache_sweep_interval(self, v: Duration) -> Self

pub fn ws_drain_deadline(self, v: Duration) -> Self

pub fn adaptive_shed_target(self, v: Duration) -> Self

pub fn cors(self, v: CorsConfig) -> Self

pub fn shutdown_trigger(self, v: Arc<Notify>) -> Self

pub fn expose_docs(self, v: bool) -> Self

pub fn ws_outbound_buffer(self, v: usize) -> Self

pub fn ws_max_connections(self, v: usize) -> Self

pub fn ws_ping_interval(self, v: Duration) -> Self

pub fn ws_idle_timeout(self, v: Duration) -> Self

pub fn with_env_overrides(self) -> Self

Apply ARCLY_* environment overrides on top of the coded values — applied automatically by the launch path so operators can retune a deployment (incident response, load tests) without a rebuild:

Variable	Field
ARCLY_REQUEST_TIMEOUT_MS	request_timeout (0 disables)
ARCLY_MAX_IN_FLIGHT	max_in_flight (0 = unlimited)
ARCLY_MAX_BODY_BYTES	max_body_bytes
ARCLY_CACHE_MAX_ENTRIES	cache_max_entries
ARCLY_WS_DRAIN_DEADLINE_MS	ws_drain_deadline
ARCLY_DRAIN_BUDGET_MS	drain_budget
ARCLY_EXPOSE_DOCS	expose_docs (true/false/1/0)

Unparseable values are ignored with a warning — a typo must never change behaviour silently or stop the boot.

Trait Implementations

impl Clone for LaunchConfig

fn clone(&self) -> LaunchConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LaunchConfig

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

Formats the value using the given formatter.

impl Default for LaunchConfig

fn default() -> Self

Returns the “default value” for a type.