samza-core/src/main/java/org/apache/samza/util/MetricsReporterLoader.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.samza.util;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import org.apache.samza.SamzaException;
import org.apache.samza.config.MetricsConfig;
import org.apache.samza.metrics.MetricsReporter;
import org.apache.samza.metrics.MetricsReporterFactory;


/**
 * Helper class that instantiates the MetricsReporter.
 */
public class MetricsReporterLoader {

  private MetricsReporterLoader() {
  }

  public static Map<String, MetricsReporter> getMetricsReporters(MetricsConfig metricsConfig, String containerName) {
    Map<String, MetricsReporter> metricsReporters = new HashMap<>();

    String diagnosticsReporterName = MetricsConfig.METRICS_SNAPSHOT_REPORTER_NAME_FOR_DIAGNOSTICS;

    // Exclude creation of diagnostics-reporter, because it is created manually in SamzaContainer (to allow sharing of
    // sysProducer between reporter and diagnosticsManager
    List<String> metricsReporterNames = metricsConfig.getMetricReporterNames()
        .stream()
        .filter(reporterName -> !reporterName.equals(diagnosticsReporterName))
        .collect(Collectors.toList());

    for (String metricsReporterName : metricsReporterNames) {
      String metricsFactoryClassName = metricsConfig.getMetricsFactoryClass(metricsReporterName)
          .orElseThrow(() -> new SamzaException(
              String.format("Metrics reporter %s missing .class config", metricsReporterName)));
      MetricsReporterFactory metricsReporterFactory =
          ReflectionUtil.getObj(metricsFactoryClassName, MetricsReporterFactory.class);
      metricsReporters.put(metricsReporterName,
                           metricsReporterFactory.getMetricsReporter(metricsReporterName,
                                                                     containerName,
                                                                     metricsConfig));
    }
    return metricsReporters;
  }
}