content: /*
   * 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
   * <p/>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p/>
   * 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.ambari.server.metrics.system.impl;
  
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.ThreadFactory;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.ambari.server.metrics.system.MetricsSink;
  import org.apache.ambari.server.metrics.system.SingleMetric;
  import org.apache.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.google.common.util.concurrent.ThreadFactoryBuilder;
  
  /**
   * @{link DatabaseMetricsSource} collects database metrics which is generated through Eclipselink PerformanceMonitor,
   * and publishes to configured Metric Sink.
   **/
  public class DatabaseMetricsSource extends AbstractMetricsSource {
    private static final Logger LOG = LoggerFactory.getLogger(DatabaseMetricsSource.class);
    private static String dbMonitorPrefix = "monitor.";
    private ExecutorService executor;
    private MetricsConfiguration configuration;
    private Set<String> includedMetricKeywords = new HashSet<>();
    private Set<Pattern> acceptedEntityPatterns = new HashSet<>();
    private Set<String> acceptedEntities = new HashSet<>();
    private static String TIMER = "Timer.";
    private static String COUNTER = "Counter.";
  
    @Override
    public void init(MetricsConfiguration metricsConfig, MetricsSink sink) {
      super.init(metricsConfig, sink);
      configuration = metricsConfig;
      initializeFilterSets();
      LOG.info("Initialized Ambari DB Metrics Source...");
    }
  
    /**
     * Initialize filter sets (Entities and keywords) to know which metrics to track vs drop.
     */
    private void initializeFilterSets() {
  
      String commaSeparatedValues = configuration.getProperty(dbMonitorPrefix + "query.keywords.include");
      if (StringUtils.isNotEmpty((commaSeparatedValues))) {
        includedMetricKeywords.addAll(Arrays.asList(commaSeparatedValues.split(",")));
      }
  
      commaSeparatedValues = configuration.getProperty(dbMonitorPrefix + "entities");
      if (StringUtils.isNotEmpty((commaSeparatedValues))) {
        String[] entityPatterns = (commaSeparatedValues.split(","));
        for (String pattern : entityPatterns) {
          acceptedEntityPatterns.add(Pattern.compile(pattern));
        }
      }
    }
  
    @Override
    public void start() {
      ThreadFactory threadFactory = new ThreadFactoryBuilder()
        .setNameFormat("DatabaseMetricsSource-%d")
        .build();
      executor = Executors.newSingleThreadExecutor(threadFactory);
      LOG.info("Started Ambari DB Metrics source...");
    }
  
    /**
     * Method to publish metrics to Sink asynchronously.
     * @param metricsMap Map of metrics to be published to Sink
     */
    public void publish(final Map<String, Long> metricsMap) {
      try {
        executor.submit(new Runnable() {
          @Override
          public void run() {
            long currentTime = System.currentTimeMillis();
  
            for (Iterator<Map.Entry<String, Long>> it = metricsMap.entrySet().iterator(); it.hasNext(); ) {
              Map.Entry<String, Long> metricEntry = it.next();
              String metricName = metricEntry.getKey();
              if (!acceptMetric(metricName)) {
                it.remove();
              }
            }
            final List<SingleMetric> metrics = new ArrayList<>();
            for (String metricName : metricsMap.keySet()) {
              double value = metricsMap.get(metricName).doubleValue();
              metrics.add(new SingleMetric(metricName, value, currentTime));
  
              /*
               * Add computed (Timer/Counter) metric.
               * Example
               * Counter Metric : Counter.ReadAllQuery.HostRoleCommandEntity = 10000
               * Timer Metric : Timer.ReadAllQuery.HostRoleCommandEntity = 50
               * Computed Metric (Avg time for the operation) : ReadAllQuery.HostRoleCommandEntity = 200 (10000 div by 50)
               */
  
              if (metricName.startsWith(COUNTER)) {
                String baseMetricName = metricName.substring(COUNTER.length());
                if (metricsMap.containsKey(TIMER + baseMetricName)) {
                  double timerValue = metricsMap.get(TIMER + baseMetricName).doubleValue();
                  if (value != 0.0) {
                    metrics.add(new SingleMetric(baseMetricName, timerValue / value , currentTime));
                  }
                }
              }
            }
            sink.publish(metrics);
          }
        });
      } catch (Exception e) {
        LOG.info("Exception when publishing Database metrics to sink", e);
      }
    }
  
    /**
     * Accept a metric to be passed to Sink or not.
     * @param metricName
     * @return true/false
     */
    public boolean acceptMetric(String metricName) {
  
      boolean accept = false;
  
      /*
        Include entities to be tracked.
        source.database.monitor.entities=Cluster(.*)Entity,Host(.*)Entity,ExecutionCommandEntity
       */
      if (acceptedEntities.contains(metricName)) {
        accept = true;
      } else {
        for (Pattern p : acceptedEntityPatterns) {
          Matcher m = p.matcher(metricName);
          if (m.find()) {
            accept = true;
          }
        }
      }
  
      /*
      Include some metrics which have the keyword even if they are not part of requested Entities.
      source.database.monitor.query.keywords.include=CacheMisses
       */
  
      for (String keyword : includedMetricKeywords) {
        if (metricName.contains(keyword)) {
          accept = true;
        }
      }
  
      String[] splits = metricName.split("\\.");
      if (splits.length <= 2) {
        accept = true; //Aggregate Counter metrics are always ok. They are not Entity specific
      }
  
      if (accept) {
        acceptedEntities.add(metricName);
        return true;
      }
  
      return false;
    }
  
    /**
     * Method to get Configuration value given key. An extra prefix is added internally.
     * @param key
     * @param defaultValue
     * @return Value corresponding to key = dbMonitorPrefix + key
     */
    public String getConfigurationValue(String key, String defaultValue) {
      return this.configuration.getProperty(dbMonitorPrefix + key, defaultValue);
    }
  }
  