Constant DEFAULT_APM_DISPATCH_TIMEOUT 

pub const DEFAULT_APM_DISPATCH_TIMEOUT: Duration;

Default time the APM v1.0 trace receiver waits for the pipeline to accept a payload: 1 second.

Matches DecoderTimeout in the reference trace-agent (apm_config.decoder_timeout), which bounds the equivalent wait there. Once this elapses the receiver sheds the payload rather than holding the tracer’s connection open: a saturated or wedged pipeline then costs the tracer one refused request instead of an indefinitely blocked one. Raise it to trade tracer-visible refusals for tolerance of longer downstream stalls; lower it to shed load sooner. A value of 0 refuses every payload the pipeline cannot accept instantly.