| /* |
| * 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.hadoop.metrics2.util; |
| |
| import java.util.Collection; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import com.google.common.base.Objects; |
| import com.google.common.collect.Maps; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.metrics2.AbstractMetric; |
| import org.apache.hadoop.metrics2.MetricsRecord; |
| import org.apache.hadoop.metrics2.MetricsTag; |
| |
| /** |
| * A metrics cache for sinks that don't support sparse updates. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class MetricsCache { |
| |
| static final Log LOG = LogFactory.getLog(MetricsCache.class); |
| static final int MAX_RECS_PER_NAME_DEFAULT = 1000; |
| |
| private final Map<String, RecordCache> map = Maps.newHashMap(); |
| private final int maxRecsPerName; |
| |
| class RecordCache |
| extends LinkedHashMap<Collection<MetricsTag>, Record> { |
| private static final long serialVersionUID = 1L; |
| private boolean gotOverflow = false; |
| |
| @Override |
| protected boolean removeEldestEntry(Map.Entry<Collection<MetricsTag>, |
| Record> eldest) { |
| boolean overflow = size() > maxRecsPerName; |
| if (overflow && !gotOverflow) { |
| LOG.warn("Metrics cache overflow at "+ size() +" for "+ eldest); |
| gotOverflow = true; |
| } |
| return overflow; |
| } |
| } |
| |
| /** |
| * Cached record |
| */ |
| public static class Record { |
| final Map<String, String> tags = Maps.newHashMap(); |
| final Map<String, Number> metrics = Maps.newHashMap(); |
| |
| /** |
| * Lookup a tag value |
| * @param key name of the tag |
| * @return the tag value |
| */ |
| public String getTag(String key) { |
| return tags.get(key); |
| } |
| |
| /** |
| * Lookup a metric value |
| * @param key name of the metric |
| * @return the metric value |
| */ |
| public Number getMetric(String key) { |
| return metrics.get(key); |
| } |
| |
| /** |
| * @return the entry set of the tags of the record |
| */ |
| public Set<Map.Entry<String, String>> tags() { |
| return tags.entrySet(); |
| } |
| |
| /** |
| * @return entry set of the metrics of the record |
| */ |
| public Set<Map.Entry<String, Number>> metrics() { |
| return metrics.entrySet(); |
| } |
| |
| @Override public String toString() { |
| return Objects.toStringHelper(this) |
| .add("tags", tags).add("metrics", metrics) |
| .toString(); |
| } |
| } |
| |
| public MetricsCache() { |
| this(MAX_RECS_PER_NAME_DEFAULT); |
| } |
| |
| /** |
| * Construct a metrics cache |
| * @param maxRecsPerName limit of the number records per record name |
| */ |
| public MetricsCache(int maxRecsPerName) { |
| this.maxRecsPerName = maxRecsPerName; |
| } |
| |
| /** |
| * Update the cache and return the current cached record |
| * @param mr the update record |
| * @param includingTags cache tag values (for later lookup by name) if true |
| * @return the updated cache record |
| */ |
| public Record update(MetricsRecord mr, boolean includingTags) { |
| String name = mr.name(); |
| RecordCache recordCache = map.get(name); |
| if (recordCache == null) { |
| recordCache = new RecordCache(); |
| map.put(name, recordCache); |
| } |
| Collection<MetricsTag> tags = mr.tags(); |
| Record record = recordCache.get(tags); |
| if (record == null) { |
| record = new Record(); |
| recordCache.put(tags, record); |
| } |
| for (AbstractMetric m : mr.metrics()) { |
| record.metrics.put(m.name(), m.value()); |
| } |
| if (includingTags) { |
| // mostly for some sinks that include tags as part of a dense schema |
| for (MetricsTag t : mr.tags()) { |
| record.tags.put(t.name(), t.value()); |
| } |
| } |
| return record; |
| } |
| |
| /** |
| * Update the cache and return the current cache record |
| * @param mr the update record |
| * @return the updated cache record |
| */ |
| public Record update(MetricsRecord mr) { |
| return update(mr, false); |
| } |
| |
| /** |
| * Get the cached record |
| * @param name of the record |
| * @param tags of the record |
| * @return the cached record or null |
| */ |
| public Record get(String name, Collection<MetricsTag> tags) { |
| RecordCache rc = map.get(name); |
| if (rc == null) return null; |
| return rc.get(tags); |
| } |
| } |