Enum FilterDlqPolicy 

pub enum FilterDlqPolicy {
    Reject,
    DiscardWithMetric,
    Route(Arc<dyn Fn(Vec<FilteredDlqEntry>) -> Result<(), EngineError> + Send + Sync>),
}

Available on crate feature transport and crate feature worker-batch and (crate features worker-batch or worker-pool or worker) only.

What a BatchEngine run loop does with inbound-filter DLQ entries (RecvBatch::dlq_entries).

Inbound action: dlq filters remove messages from the normal batch; those entries must go somewhere. The default is Reject so a data-loss-shaped config never passes silently.

Variants

Reject

Fail the run loop (EngineError::FilterDlqUnrouted) if any DLQ entries appear. The safe default – forces a deliberate choice.

DiscardWithMetric

Deliberately discard DLQ entries, counting them in the dfe_engine_filter_dlq_discarded_total metric. Explicit opt-in.

Route(Arc<dyn Fn(Vec<FilteredDlqEntry>) -> Result<(), EngineError> + Send + Sync>)

Hand each batch’s DLQ entries to a sink (e.g. enqueue onto a DLQ transport, or tokio::spawn an async send). Called on the run loop, so keep it cheap – offload slow work.

The sink is FALLIBLE: returning Err raises EngineError::DlqRouteFailed, which is a terminal ack-barrier failure (the source commit is skipped, the whole block re-delivered). A sink that deliberately tolerates loss should return Ok after counting the drop; to discard ALL entries by policy use DiscardWithMetric instead.

Trait Implementations

impl Clone for FilterDlqPolicy

fn clone(&self) -> FilterDlqPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FilterDlqPolicy

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

Formats the value using the given formatter.

impl Default for FilterDlqPolicy

fn default() -> FilterDlqPolicy

Returns the “default value” for a type.