Instrumentation - Reporter

About

A reporter is a collector that:

runs in the instrumented application
will collect the metrics at regulier interval from a registry
send them to an output destination, mostly a backend metrics server.

Example

Dropwizard

Example:

slf4j has the destination with the Slf4jReporter

// Initialize Dropwizard metric registry
String registryName = "registry";
MetricRegistry registry = SharedMetricRegistries.getOrCreate(registryName);
SharedMetricRegistries.setDefault(registryName);

// Initialize Dropwizard reporter
Logger dropWizardlogger = LoggerFactory.getLogger(DropWizard.class);

// The reporter
Slf4jReporter reporter = Slf4jReporter.forRegistry(registry)
  .outputTo(dropWizardlogger)
  .convertRatesTo(TimeUnit.SECONDS)
  .convertDurationsTo(TimeUnit.MILLISECONDS)
  .build();
reporter.start(1, TimeUnit.MINUTES);

with the CsvReporter, it doesn't write to a file, but instead writes a series of files to a specified directory.

String registryName = "vertx";
MetricRegistry registry = SharedMetricRegistries.getOrCreate(registryName);
SharedMetricRegistries.setDefault(registryName);

// A directory path
Path csvPath = Paths.get("logs");

// The reporter
CsvReporter reporter = CsvReporter.forRegistry(registry)
  .convertRatesTo(TimeUnit.SECONDS)
  .convertDurationsTo(TimeUnit.MILLISECONDS)
  .build(csvPath.toFile());

// Start
reporter.start(1, TimeUnit.MINUTES);