MetricsCollector.java

/*
 * Copyright © 2015 Cask Data, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package co.cask.tephra.metrics;

import com.google.common.util.concurrent.Service;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;

/**
 * Basic API for Tephra to support system metrics.
 */
public interface MetricsCollector extends Service {
  /**
   * Report a metric as an absolute value.
   */
  void gauge(String metricName, int value, String... tags);

  /**
   * Report a metric as a count over a given time duration.  This method uses an implicit count of 1.
   */
  void rate(String metricName);

  /**
   * Report a metric as a count over a given time duration.
   */
  void rate(String metricName, int count);

  /**
   * Report a metric calculating the distribution of the value.
   */
  void histogram(String metricName, int value);

  /**
   * Called before the collector service is started, allowing the collector to setup any
   * required configuration.
   */
  void configure(Configuration conf);
}