package io.dropwizard.metrics;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.Marker;
import java.util.Map.Entry;
import java.util.SortedMap;
import java.util.concurrent.TimeUnit;
/**
* A reporter class for logging metrics values to a SLF4J {@link Logger} periodically, similar to
* {@link ConsoleReporter} or {@link CsvReporter}, but using the SLF4J framework instead. It also
* supports specifying a {@link Marker} instance that can be used by custom appenders and filters
* for the bound logging toolkit to further process metrics reports.
*/
public class Slf4jReporter extends ScheduledReporter {
/**
* Returns a new {@link Builder} for {@link Slf4jReporter}.
*
* @param registry the registry to report
* @return a {@link Builder} instance for a {@link Slf4jReporter}
*/
public static Builder forRegistry(MetricRegistry registry) {
return new Builder(registry);
}
public enum LoggingLevel {TRACE, DEBUG, INFO, WARN, ERROR}
/**
* A builder for {@link Slf4jReporter} instances. Defaults to logging to {@code metrics}, not
* using a marker, converting rates to events/second, converting durations to milliseconds, and
* not filtering metrics.
*/
public static class Builder {
private final MetricRegistry registry;
private Logger logger;
private LoggingLevel loggingLevel;
private Marker marker;
private String prefix;
private TimeUnit rateUnit;
private TimeUnit durationUnit;
private MetricFilter filter;
private MetricNameFormatter nameFormatter;
private Builder(MetricRegistry registry) {
this.registry = registry;
this.logger = LoggerFactory.getLogger("metrics");
this.marker = null;
this.prefix = "";
this.rateUnit = TimeUnit.SECONDS;
this.durationUnit = TimeUnit.MILLISECONDS;
this.filter = MetricFilter.ALL;
this.loggingLevel = LoggingLevel.INFO;
this.nameFormatter = MetricNameFormatter.METRIC_NAME_TOSTRING;
}
/**
* Log metrics to the given logger.
*
* @param logger an SLF4J {@link Logger}
* @return {@code this}
*/
public Builder outputTo(Logger logger) {
this.logger = logger;
return this;
}
/**
* Mark all logged metrics with the given marker.
*
* @param marker an SLF4J {@link Marker}
* @return {@code this}
*/
public Builder markWith(Marker marker) {
this.marker = marker;
return this;
}
/**
* Prefix all metric names with the given string.
*
* @param prefix the prefix for all metric names
* @return {@code this}
*/
public Builder prefixedWith(String prefix) {
this.prefix = prefix;
return this;
}
/**
* Convert rates to the given time unit.
*
* @param rateUnit a unit of time
* @return {@code this}
*/
public Builder convertRatesTo(TimeUnit rateUnit) {
this.rateUnit = rateUnit;
return this;
}
/**
* Convert durations to the given time unit.
*
* @param durationUnit a unit of time
* @return {@code this}
*/
public Builder convertDurationsTo(TimeUnit durationUnit) {
this.durationUnit = durationUnit;
return this;
}
/**
* Only report metrics which match the given filter.
*
* @param filter a {@link MetricFilter}
* @return {@code this}
*/
public Builder filter(MetricFilter filter) {
this.filter = filter;
return this;
}
/**
* Use Logging Level when reporting.
*
* @param loggingLevel a (@link Slf4jReporter.LoggingLevel}
* @return {@code this}
*/
public Builder withLoggingLevel(LoggingLevel loggingLevel) {
this.loggingLevel = loggingLevel;
return this;
}
/**
* Use given {@link MetricNameFormatter} when creating the metric name string
* @param nameformatter the formatter to use
* @return {@code this}
*/
public Builder withNameFormatter(MetricNameFormatter nameformatter) {
this.nameFormatter = nameformatter;
return this;
}
/**
* Builds a {@link Slf4jReporter} with the given properties.
*
* @return a {@link Slf4jReporter}
*/
public Slf4jReporter build() {
LoggerProxy loggerProxy;
switch (loggingLevel) {
case TRACE:
loggerProxy = new TraceLoggerProxy(logger);
break;
case INFO:
loggerProxy = new InfoLoggerProxy(logger);
break;
case WARN:
loggerProxy = new WarnLoggerProxy(logger);
break;
case ERROR:
loggerProxy = new ErrorLoggerProxy(logger);
break;
default:
case DEBUG:
loggerProxy = new DebugLoggerProxy(logger);
break;
}
return new Slf4jReporter(registry, loggerProxy, marker, prefix, rateUnit, durationUnit, filter,nameFormatter);
}
}
private final LoggerProxy loggerProxy;
private final Marker marker;
private final MetricName prefix;
private final MetricNameFormatter nameFormatter;
private Slf4jReporter(MetricRegistry registry,
LoggerProxy loggerProxy,
Marker marker,
String prefix,
TimeUnit rateUnit,
TimeUnit durationUnit,
MetricFilter filter,
MetricNameFormatter nameFormatter) {
super(registry, "logger-reporter", filter, rateUnit, durationUnit);
this.loggerProxy = loggerProxy;
this.marker = marker;
this.prefix = MetricName.build(prefix);
this.nameFormatter = nameFormatter;
}
@Override
public void report(SortedMap<MetricName, Gauge> gauges,
SortedMap<MetricName, Counter> counters,
SortedMap<MetricName, Histogram> histograms,
SortedMap<MetricName, Meter> meters,
SortedMap<MetricName, Timer> timers) {
if (loggerProxy.isEnabled(marker)) {
for (Entry<MetricName, Gauge> entry : gauges.entrySet()) {
logGauge(entry.getKey(), entry.getValue());
}
for (Entry<MetricName, Counter> entry : counters.entrySet()) {
logCounter(entry.getKey(), entry.getValue());
}
for (Entry<MetricName, Histogram> entry : histograms.entrySet()) {
logHistogram(entry.getKey(), entry.getValue());
}
for (Entry<MetricName, Meter> entry : meters.entrySet()) {
logMeter(entry.getKey(), entry.getValue());
}
for (Entry<MetricName, Timer> entry : timers.entrySet()) {
logTimer(entry.getKey(), entry.getValue());
}
}
}
private void logTimer(MetricName name, Timer timer) {
final Snapshot snapshot = timer.getSnapshot();
loggerProxy.log(marker,
"type={}, name={}, count={}, min={}, max={}, mean={}, stddev={}, median={}, " +
"p75={}, p95={}, p98={}, p99={}, p999={}, mean_rate={}, m1={}, m5={}, " +
"m15={}, rate_unit={}, duration_unit={}",
"TIMER",
formatName(name),
timer.getCount(),
convertDuration(snapshot.getMin()),
convertDuration(snapshot.getMax()),
convertDuration(snapshot.getMean()),
convertDuration(snapshot.getStdDev()),
convertDuration(snapshot.getMedian()),
convertDuration(snapshot.get75thPercentile()),
convertDuration(snapshot.get95thPercentile()),
convertDuration(snapshot.get98thPercentile()),
convertDuration(snapshot.get99thPercentile()),
convertDuration(snapshot.get999thPercentile()),
convertRate(timer.getMeanRate()),
convertRate(timer.getOneMinuteRate()),
convertRate(timer.getFiveMinuteRate()),
convertRate(timer.getFifteenMinuteRate()),
getRateUnit(),
getDurationUnit());
}
private void logMeter(MetricName name, Meter meter) {
loggerProxy.log(marker,
"type={}, name={}, count={}, mean_rate={}, m1={}, m5={}, m15={}, rate_unit={}",
"METER",
formatName(name),
meter.getCount(),
convertRate(meter.getMeanRate()),
convertRate(meter.getOneMinuteRate()),
convertRate(meter.getFiveMinuteRate()),
convertRate(meter.getFifteenMinuteRate()),
getRateUnit());
}
private void logHistogram(MetricName name, Histogram histogram) {
final Snapshot snapshot = histogram.getSnapshot();
loggerProxy.log(marker,
"type={}, name={}, count={}, min={}, max={}, mean={}, stddev={}, " +
"median={}, p75={}, p95={}, p98={}, p99={}, p999={}",
"HISTOGRAM",
formatName(name),
histogram.getCount(),
snapshot.getMin(),
snapshot.getMax(),
snapshot.getMean(),
snapshot.getStdDev(),
snapshot.getMedian(),
snapshot.get75thPercentile(),
snapshot.get95thPercentile(),
snapshot.get98thPercentile(),
snapshot.get99thPercentile(),
snapshot.get999thPercentile());
}
private void logCounter(MetricName name, Counter counter) {
loggerProxy.log(marker, "type={}, name={}, count={}", "COUNTER", formatName(name), counter.getCount());
}
private void logGauge(MetricName name, Gauge gauge) {
loggerProxy.log(marker, "type={}, name={}, value={}", "GAUGE", formatName(name), gauge.getValue());
}
@Override
protected String getRateUnit() {
return "events/" + super.getRateUnit();
}
private String formatName(MetricName name) {
name = MetricName.join(prefix,name);
return nameFormatter.formatMetricName(name);
}
/* private class to allow logger configuration */
static abstract class LoggerProxy {
protected final Logger logger;
public LoggerProxy(Logger logger) {
this.logger = logger;
}
abstract void log(Marker marker, String format, Object... arguments);
abstract boolean isEnabled(Marker marker);
}
/* private class to allow logger configuration */
private static class DebugLoggerProxy extends LoggerProxy {
public DebugLoggerProxy(Logger logger) {
super(logger);
}
@Override
public void log(Marker marker, String format, Object... arguments) {
logger.debug(marker, format, arguments);
}
@Override
public boolean isEnabled(Marker marker) {
return logger.isDebugEnabled(marker);
}
}
/* private class to allow logger configuration */
private static class TraceLoggerProxy extends LoggerProxy {
public TraceLoggerProxy(Logger logger) {
super(logger);
}
@Override
public void log(Marker marker, String format, Object... arguments) {
logger.trace(marker, format, arguments);
}
@Override
public boolean isEnabled(Marker marker) {
return logger.isTraceEnabled(marker);
}
}
/* private class to allow logger configuration */
private static class InfoLoggerProxy extends LoggerProxy {
public InfoLoggerProxy(Logger logger) {
super(logger);
}
@Override
public void log(Marker marker, String format, Object... arguments) {
logger.info(marker, format, arguments);
}
@Override
public boolean isEnabled(Marker marker) {
return logger.isInfoEnabled(marker);
}
}
/* private class to allow logger configuration */
private static class WarnLoggerProxy extends LoggerProxy {
public WarnLoggerProxy(Logger logger) {
super(logger);
}
@Override
public void log(Marker marker, String format, Object... arguments) {
logger.warn(marker, format, arguments);
}
@Override
public boolean isEnabled(Marker marker) {
return logger.isWarnEnabled(marker);
}
}
/* private class to allow logger configuration */
private static class ErrorLoggerProxy extends LoggerProxy {
public ErrorLoggerProxy(Logger logger) {
super(logger);
}
@Override
public void log(Marker marker, String format, Object... arguments) {
logger.error(marker, format, arguments);
}
@Override
public boolean isEnabled(Marker marker) {
return logger.isErrorEnabled(marker);
}
}
}