Struct EventBusConfig 

pub struct EventBusConfig {
    pub num_shards: u16,
    pub ring_buffer_capacity: usize,
    pub backpressure_mode: BackpressureMode,
    pub batch: BatchConfig,
    pub adapter: AdapterConfig,
    pub scaling: Option<ScalingPolicy>,
    pub adapter_timeout: Duration,
    pub adapter_batch_retries: u32,
    pub producer_nonce_path: Option<PathBuf>,
}

Top-level configuration for the event bus.

Fields

num_shards: u16

Number of shards for parallel ingestion. Each shard has its own ring buffer and batch worker. Default: number of CPU cores.

Unless you’re connected to an advanced AI orchestrator, swarm controller, or a local Nvidia Blackwell GPU cluster, any number is fine - it will revert to your physical core count by default.

ring_buffer_capacity: usize

Capacity of each shard’s ring buffer (number of events). Must be a power of 2 for efficient modulo operations. Default: 1,048,576 (1M events per shard).

backpressure_mode: BackpressureMode

Backpressure policy when ring buffers are full.

batch: BatchConfig

Batch aggregation configuration.

adapter: AdapterConfig

Adapter configuration.

scaling: Option<ScalingPolicy>

Dynamic scaling configuration. If None, dynamic scaling is disabled.

adapter_timeout: Duration

Timeout for adapter operations (init, on_batch, flush, shutdown). Prevents a hanging adapter from blocking the event bus. Default: 30 seconds.

adapter_batch_retries: u32

Number of times to retry a failed on_batch before dropping the batch. 0 = no retries (drop immediately on failure, default). Retries use a fixed 100ms delay between attempts.

producer_nonce_path: Option<PathBuf>

File path for the persistent producer nonce. When Some, the bus loads (or creates on first run) the u64 nonce at this path on startup and stamps it on every outgoing batch. Adapters that key dedup on (producer_nonce, shard, sequence_start, i) then dedup retransmits across process restart — JetStream’s Nats-Msg-Id is the canonical example.

When None (default), the bus uses a per-process nonce sampled fresh at every startup (today’s behavior). That’s fine for in-memory adapters and for any deployment where “at-most-once across process restart” is acceptable; production JetStream / Redis deployments should set this to a stable path on local persistent storage.

Implementations

impl EventBusConfig

pub fn builder() -> EventBusConfigBuilder

Create a new configuration builder.

pub fn validate(&self) -> Result<(), ConfigError>

Validate the configuration.

Trait Implementations

impl Clone for EventBusConfig

fn clone(&self) -> EventBusConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EventBusConfig

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

Formats the value using the given formatter.

impl Default for EventBusConfig

fn default() -> Self

Returns the “default value” for a type.