in src/main/java/com/googlesource/gerrit/plugins/kafka/config/KafkaProperties.java [59:68]
private void setDefaults() {
put("acks", "all");
put("retries", 0);
put("batch.size", 16384);
put("linger.ms", 1);
put("buffer.memory", 33554432);
put("key.serializer", KAFKA_STRING_SERIALIZER);
put("value.serializer", KAFKA_STRING_SERIALIZER);
put("reconnect.backoff.ms", 5000L);
}