consumer.ts

// Attempt to flush to amplitude
  // Retryable failed events are sent to a retry queue
  // Otherwise an application error is logged
  try {
    await flushAmplitude()
  } catch (e) {
    if (!(e instanceof AmplitudeFlushError)) {
      throw e
    }

    for (const failedEventDescription of e.failedEventDescriptions) {
      const { isRetryable, event: amplitudeEvent, retryInMs } = failedEventDescription

      // Note that while an event is retryable, it may still have been processed by Amplitude
      // This is because Amplitude only returns a single status per batch
      // Fortunately, there is no risk of event duplication here because Amplitude
      // Performs a deduplication based on each Amplitude event's `insert_id`
      if (isRetryable) {
        // TODO: send to retry queue here
        console.log('Retry amplitudeEvent %o in %s ms', amplitudeEvent, retryInMs)
      } else {
        console.error('Error - flush error for event: ' + JSON.stringify(failedEventDescription))
      }
    }
  }