@ConditionalOnMissingBean(name = "primaryMetricWriter")
public MetricWriter primaryMetricWriter(
@Qualifier("metricsChannel") SubscribableChannel channel,
List<MetricWriter> writers) {
final MetricWriter observer = new CompositeMetricWriter(writers);
channel.subscribe(new MetricWriterMessageHandler(observer));
return new MessageChannelMetricWriter(channel);
}