order

This paper mainly studies the custom statsd index prefix of springboot2

background

micrometer is introduced in springboot2. The 1.x version of spring.metrics.export.statsd.prefix has been marked as obsolete in version 2, but the corresponding configuration items are not given in version 2.

FlavorStatsdLineBuilder

micrometer-registry-statsd-1.0.1-sources.jar!/io/micrometer/statsd/internal/FlavorStatsdLineBuilder.java

/**
 * A Statsd serializer for a particular {@link Meter} that formats the line in different
 * ways depending on the prevailing {@link StatsdFlavor}.
 *
 * @author Jon Schneider
 */
public class FlavorStatsdLineBuilder implements StatsdLineBuilder {
    private final Meter.Id id;
    private final StatsdFlavor flavor;
    private final HierarchicalNameMapper nameMapper;
    private final MeterRegistry.Config config;

    private final Function<NamingConvention, String> datadogTagString;
    private final Function<NamingConvention, String> telegrafTagString;

    public FlavorStatsdLineBuilder(Meter.Id id, StatsdFlavor flavor, HierarchicalNameMapper nameMapper, MeterRegistry.Config config) {
        this.id = id;
        this.flavor = flavor;
        this.nameMapper = nameMapper;
        this.config = config;

        // service:payroll,region:us-west
        this.datadogTagString = memoize(convention ->
                id.getTags().iterator().hasNext() ?
                        id.getConventionTags(convention).stream()
                                .map(t -> t.getKey() + ":" + t.getValue())
                                .collect(Collectors.joining(","))
                        : null
        );

        // service=payroll,region=us-west
        this.telegrafTagString = memoize(convention ->
                id.getTags().iterator().hasNext() ?
                        id.getConventionTags(convention).stream()
                                .map(t -> t.getKey() + "=" + t.getValue())
                                .collect(Collectors.joining(","))
                        : null
        );
    }

    @Override
    public String count(long amount, Statistic stat) {
        return line(Long.toString(amount), stat, "c");
    }

    @Override
    public String gauge(double amount, Statistic stat) {
        return line(DoubleFormat.decimalOrNan(amount), stat, "g");
    }

    @Override
    public String histogram(double amount) {
        return line(DoubleFormat.decimalOrNan(amount), null, "h");
    }

    @Override
    public String timing(double timeMs) {
        return line(DoubleFormat.decimalOrNan(timeMs), null, "ms");
    }

    private String line(String amount, @Nullable Statistic stat, String type) {
        switch (flavor) {
            case ETSY:
                return metricName(stat) + ":" + amount + "|" + type;
            case DATADOG:
                return metricName(stat) + ":" + amount + "|" + type + tags(stat, datadogTagString.apply(config.namingConvention()),":", "|#");
            case TELEGRAF:
            default:
                return metricName(stat) + tags(stat, telegrafTagString.apply(config.namingConvention()),"=", ",") + ":" + amount + "|" + type;
        }
    }

    private String tags(@Nullable Statistic stat, String otherTags, String keyValueSeparator, String preamble) {
        String tags = of(stat == null ? null : "statistic" + keyValueSeparator + stat.getTagValueRepresentation(), otherTags)
                .filter(Objects::nonNull)
                .collect(Collectors.joining(","));

        if(!tags.isEmpty())
            tags = preamble + tags;
        return tags;
    }

    private String metricName(@Nullable Statistic stat) {
        switch (flavor) {
            case ETSY:
                return nameMapper.toHierarchicalName(stat != null ? id.withTag(stat) : id, config.namingConvention());
            case DATADOG:
            case TELEGRAF:
            default:
                return config.namingConvention().name(id.getName(), id.getType(), id.getBaseUnit());
        }
    }
}

HierarchicalNameMapper

micrometer-core-1.0.1-sources.jar!/io/micrometer/core/instrument/util/HierarchicalNameMapper.java

/**
 * Defines the mapping between a combination of name + dimensional tags and a hierarchical name.
 *
 * @author Jon Schneider
 */
public interface HierarchicalNameMapper {
    /**
     * Sort tags alphabetically by key and append tag key values to the name with '.', e.g.
     * {@code http_server_requests.response.200.method.GET}
     */
    HierarchicalNameMapper DEFAULT = (id, convention) -> {
        String tags = "";

        if (id.getTags().iterator().hasNext()) {
            tags = "." + id.getConventionTags(convention).stream()
                .map(t -> t.getKey() + "." + t.getValue())
                .map(nameSegment -> nameSegment.replace(" ", "_"))
                .collect(Collectors.joining("."));
        }

        return id.getConventionName(convention) + tags;
    };

    String toHierarchicalName(Meter.Id id, NamingConvention convention);
}

• StatsdMetricsExportAutoConfiguration spring-boot-actuator-autoconfigure-2.0.0.RELEASE-sources.jar!/org/springframework/boot/actuate/autoconfigure/metrics/export/statsd/StatsdMetricsExportAutoConfiguration.java

	@Bean
	@ConditionalOnMissingBean
	public HierarchicalNameMapper hierarchicalNameMapper() {
		return HierarchicalNameMapper.DEFAULT;
	}

custom

By customizing a hierarchical name mapper, you can customize the prefix of the statsd indicator. The example is as follows

    @Bean
    public HierarchicalNameMapper hierarchicalNameMapper() {
        return new HierarchicalNameMapper(){

            @Override
            public String toHierarchicalName(Meter.Id id, NamingConvention convention) {
                String tags = "";

                if (id.getTags().iterator().hasNext()) {
                    tags = "." + id.getConventionTags(convention).stream()
                            .map(t -> t.getKey() + "." + t.getValue())
                            .map(nameSegment -> nameSegment.replace(" ", "_"))
                            .collect(Collectors.joining("."));
                }

                return "demo." + id.getConventionName(convention) + tags;
            }
        };
    }

Summary

At present, spring boot 2 does not directly support specifying the prefix of statsd through the configuration file, but it can be implemented by customizing the hierarchical name mapper with a little code.

doc

• management.metrics.export.tags-as-prefix property seems not to be honored in Spring Boot 2.0.0.RELEASE #12557