protected EncodedLogEvent encodeLogEvent(LogEvent event) {
    return new ByteArrayEncodedLogEvent(serde.toBytes(subLog(event)));
  }
If async-Logger is enabled, the log-event is sent directly to the systemProducer. Else, the event is serialized
and added to a bounded blocking queue, before returning to the "synchronous" caller.
@param event the log event to append
@throws InterruptedException
samza-log4j2/src/main/java/org/apache/samza/logging/log4j2/StreamAppender.java