org.apache.solr.search.LFUCache Maven / Gradle / Ivy
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* 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.solr.search;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.lang.invoke.MethodHandles;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.TimeUnit;
import org.apache.lucene.util.Accountable;
import org.apache.lucene.util.RamUsageEstimator;
import org.apache.solr.common.SolrException;
import org.apache.solr.metrics.MetricsMap;
import org.apache.solr.metrics.SolrMetricsContext;
import org.apache.solr.util.ConcurrentLFUCache;
import org.apache.solr.util.IOFunction;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.solr.common.params.CommonParams.NAME;
/**
* SolrCache based on ConcurrentLFUCache implementation.
*
* This implementation does not use a separate cleanup thread. Instead it uses the calling thread
* itself to do the cleanup when the size of the cache exceeds certain limits.
*
* Also see SolrCaching
*
* This API is experimental and subject to change
*
* @see org.apache.solr.util.ConcurrentLFUCache
* @see org.apache.solr.search.SolrCache
* @since solr 3.6
* @deprecated This cache implementation is deprecated and will be removed in Solr 9.0.
* Use {@link CaffeineCache} instead.
*/
public class LFUCache implements SolrCache, Accountable {
private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
private static final long BASE_RAM_BYTES_USED = RamUsageEstimator.shallowSizeOfInstance(LFUCache.class);
public static final String TIME_DECAY_PARAM = "timeDecay";
public static final String CLEANUP_THREAD_PARAM = "cleanupThread";
public static final String INITIAL_SIZE_PARAM = "initialSize";
public static final String MIN_SIZE_PARAM = "minSize";
public static final String ACCEPTABLE_SIZE_PARAM = "acceptableSize";
public static final String AUTOWARM_COUNT_PARAM = "autowarmCount";
public static final String SHOW_ITEMS_PARAM = "showItems";
// contains the statistics objects for all open caches of the same type
private List statsList;
private long warmupTime = 0;
private String name;
private int autowarmCount;
private State state;
private CacheRegenerator regenerator;
private String description = "Concurrent LFU Cache";
private ConcurrentLFUCache cache;
private int showItems = 0;
private Boolean timeDecay = true;
private int maxIdleTimeSec;
private MetricsMap cacheMap;
private Set metricNames = ConcurrentHashMap.newKeySet();
private SolrMetricsContext solrMetricsContext;
private int maxSize;
private int minSizeLimit;
private int initialSize;
private int acceptableSize;
private boolean cleanupThread;
@Override
public Object init(Map args, Object persistence, CacheRegenerator regenerator) {
state = State.CREATED;
this.regenerator = regenerator;
name = (String) args.get(NAME);
String str = (String) args.get(SIZE_PARAM);
maxSize = str == null ? 1024 : Integer.parseInt(str);
str = (String) args.get(MIN_SIZE_PARAM);
if (str == null) {
minSizeLimit = (int) (maxSize * 0.9);
} else {
minSizeLimit = Integer.parseInt(str);
}
checkAndAdjustLimits();
str = (String) args.get(ACCEPTABLE_SIZE_PARAM);
if (str == null) {
acceptableSize = (int) (maxSize * 0.95);
} else {
acceptableSize = Integer.parseInt(str);
}
// acceptable limit should be somewhere between minLimit and limit
acceptableSize = Math.max(minSizeLimit, acceptableSize);
str = (String) args.get(INITIAL_SIZE_PARAM);
initialSize = str == null ? maxSize : Integer.parseInt(str);
str = (String) args.get(AUTOWARM_COUNT_PARAM);
autowarmCount = str == null ? 0 : Integer.parseInt(str);
str = (String) args.get(CLEANUP_THREAD_PARAM);
cleanupThread = str == null ? false : Boolean.parseBoolean(str);
str = (String) args.get(SHOW_ITEMS_PARAM);
showItems = str == null ? 0 : Integer.parseInt(str);
// Don't make this "efficient" by removing the test, default is true and omitting the param will make it false.
str = (String) args.get(TIME_DECAY_PARAM);
timeDecay = (str == null) ? true : Boolean.parseBoolean(str);
str = (String) args.get(MAX_IDLE_TIME_PARAM);
if (str == null) {
maxIdleTimeSec = -1;
} else {
maxIdleTimeSec = Integer.parseInt(str);
}
description = generateDescription();
cache = new ConcurrentLFUCache<>(maxSize, minSizeLimit, acceptableSize, initialSize,
cleanupThread, false, null, timeDecay, maxIdleTimeSec);
cache.setAlive(false);
statsList = (List) persistence;
if (statsList == null) {
// must be the first time a cache of this type is being created
// Use a CopyOnWriteArrayList since puts are very rare and iteration may be a frequent operation
// because it is used in getStatistics()
statsList = new CopyOnWriteArrayList<>();
// the first entry will be for cumulative stats of caches that have been closed.
statsList.add(new ConcurrentLFUCache.Stats());
}
statsList.add(cache.getStats());
return statsList;
}
private String generateDescription() {
String descr = "Concurrent LFU Cache(maxSize=" + maxSize + ", initialSize=" + initialSize +
", minSize=" + minSizeLimit + ", acceptableSize=" + acceptableSize + ", cleanupThread=" + cleanupThread +
", timeDecay=" + timeDecay +
", maxIdleTime=" + maxIdleTimeSec;
if (autowarmCount > 0) {
descr += ", autowarmCount=" + autowarmCount + ", regenerator=" + regenerator;
}
descr += ')';
return descr;
}
@Override
public String name() {
return name;
}
@Override
public int size() {
return cache.size();
}
@Override
public V put(K key, V value) {
return cache.put(key, value);
}
@Override
public V remove(K key) {
return cache.remove(key);
}
@Override
public V computeIfAbsent(K key, IOFunction mappingFunction) {
return cache.computeIfAbsent(key, k -> {
try {
return mappingFunction.apply(k);
} catch (IOException e) {
throw new UncheckedIOException(e);
}
});
}
@Override
public V get(K key) {
return cache.get(key);
}
@Override
public void clear() {
cache.clear();
}
@Override
public void setState(State state) {
this.state = state;
cache.setAlive(state == State.LIVE);
}
@Override
public State getState() {
return state;
}
@Override
public void warm(SolrIndexSearcher searcher, SolrCache old) {
if (regenerator == null) return;
long warmingStartTime = System.nanoTime();
LFUCache other = (LFUCache) old;
// warm entries
if (autowarmCount != 0) {
int sz = other.size();
if (autowarmCount != -1) sz = Math.min(sz, autowarmCount);
Map items = other.cache.getMostUsedItems(sz);
Map.Entry[] itemsArr = new Map.Entry[items.size()];
int counter = 0;
for (Object mapEntry : items.entrySet()) {
itemsArr[counter++] = (Map.Entry) mapEntry;
}
for (int i = itemsArr.length - 1; i >= 0; i--) {
try {
boolean continueRegen = regenerator.regenerateItem(searcher,
this, old, itemsArr[i].getKey(), itemsArr[i].getValue());
if (!continueRegen) break;
} catch (Exception e) {
SolrException.log(log, "Error during auto-warming of key:" + itemsArr[i].getKey(), e);
}
}
}
warmupTime = TimeUnit.MILLISECONDS.convert(System.nanoTime() - warmingStartTime, TimeUnit.NANOSECONDS);
}
@Override
public void close() throws IOException {
SolrCache.super.close();
// add the stats to the cumulative stats object (the first in the statsList)
statsList.get(0).add(cache.getStats());
statsList.remove(cache.getStats());
cache.destroy();
}
//////////////////////// SolrInfoMBeans methods //////////////////////
@Override
public String getName() {
return LFUCache.class.getName();
}
@Override
public String getDescription() {
return description;
}
@Override
public Category getCategory() {
return Category.CACHE;
}
// returns a ratio, not a percent.
private static String calcHitRatio(long lookups, long hits) {
if (lookups == 0) return "0.00";
if (lookups == hits) return "1.00";
int hundredths = (int) (hits * 100 / lookups); // rounded down
if (hundredths < 10) return "0.0" + hundredths;
return "0." + hundredths;
}
@Override
public SolrMetricsContext getSolrMetricsContext() {
return solrMetricsContext;
}
@Override
public void initializeMetrics(SolrMetricsContext parentContext, String scope) {
solrMetricsContext = parentContext.getChildContext(this);
cacheMap = new MetricsMap((detailed, map) -> {
if (cache != null) {
ConcurrentLFUCache.Stats stats = cache.getStats();
long lookups = stats.getCumulativeLookups();
long hits = stats.getCumulativeHits();
long inserts = stats.getCumulativePuts();
long evictions = stats.getCumulativeEvictions();
long idleEvictions = stats.getCumulativeIdleEvictions();
long size = stats.getCurrentSize();
map.put(LOOKUPS_PARAM, lookups);
map.put(HITS_PARAM, hits);
map.put(HIT_RATIO_PARAM, calcHitRatio(lookups, hits));
map.put(INSERTS_PARAM, inserts);
map.put(EVICTIONS_PARAM, evictions);
map.put(SIZE_PARAM, size);
map.put(MAX_SIZE_PARAM, maxSize);
map.put(MIN_SIZE_PARAM, minSizeLimit);
map.put(ACCEPTABLE_SIZE_PARAM, acceptableSize);
map.put(AUTOWARM_COUNT_PARAM, autowarmCount);
map.put(CLEANUP_THREAD_PARAM, cleanupThread);
map.put(SHOW_ITEMS_PARAM, showItems);
map.put(TIME_DECAY_PARAM, timeDecay);
map.put(RAM_BYTES_USED_PARAM, ramBytesUsed());
map.put(MAX_IDLE_TIME_PARAM, maxIdleTimeSec);
map.put("idleEvictions", idleEvictions);
map.put("warmupTime", warmupTime);
long clookups = 0;
long chits = 0;
long cinserts = 0;
long cevictions = 0;
long cidleEvictions = 0;
// NOTE: It is safe to iterate on a CopyOnWriteArrayList
for (ConcurrentLFUCache.Stats statistics : statsList) {
clookups += statistics.getCumulativeLookups();
chits += statistics.getCumulativeHits();
cinserts += statistics.getCumulativePuts();
cevictions += statistics.getCumulativeEvictions();
cidleEvictions += statistics.getCumulativeIdleEvictions();
}
map.put("cumulative_lookups", clookups);
map.put("cumulative_hits", chits);
map.put("cumulative_hitratio", calcHitRatio(clookups, chits));
map.put("cumulative_inserts", cinserts);
map.put("cumulative_evictions", cevictions);
map.put("cumulative_idleEvictions", cidleEvictions);
if (detailed && showItems != 0) {
Map items = cache.getMostUsedItems(showItems == -1 ? Integer.MAX_VALUE : showItems);
for (Map.Entry e : (Set) items.entrySet()) {
Object k = e.getKey();
Object v = e.getValue();
String ks = "item_" + k;
String vs = v.toString();
map.put(ks, vs);
}
}
}
});
solrMetricsContext.gauge(this, cacheMap, true, scope, getCategory().toString());
}
// for unit tests only
MetricsMap getMetricsMap() {
return cacheMap;
}
@Override
public Set getMetricNames() {
return metricNames;
}
@Override
public String toString() {
return name + (cacheMap != null ? cacheMap.getValue().toString() : "");
}
@Override
public long ramBytesUsed() {
synchronized (statsList) {
return BASE_RAM_BYTES_USED +
RamUsageEstimator.sizeOfObject(name) +
RamUsageEstimator.sizeOfObject(metricNames) +
RamUsageEstimator.sizeOfObject(statsList) +
RamUsageEstimator.sizeOfObject(cache);
}
}
@Override
public int getMaxSize() {
return maxSize != Integer.MAX_VALUE ? maxSize : -1;
}
@Override
public void setMaxSize(int maxSize) {
if (maxSize > 0) {
this.maxSize = maxSize;
} else {
this.maxSize = Integer.MAX_VALUE;
}
checkAndAdjustLimits();
cache.setUpperWaterMark(maxSize);
cache.setLowerWaterMark(minSizeLimit);
description = generateDescription();
}
@Override
public int getMaxRamMB() {
return -1;
}
@Override
public void setMaxRamMB(int maxRamMB) {
// no-op
}
private void checkAndAdjustLimits() {
if (minSizeLimit <= 0) minSizeLimit = 1;
if (maxSize <= minSizeLimit) {
if (maxSize > 1) {
minSizeLimit = maxSize - 1;
} else {
maxSize = minSizeLimit + 1;
}
}
}
}