mreutegg commented on code in PR #635: URL: https://github.com/apache/jackrabbit-oak/pull/635#discussion_r949119924
########## oak-store-document/src/main/java/org/apache/jackrabbit/oak/plugins/document/util/ThrottlingDocumentStoreWrapper.java: ########## @@ -0,0 +1,241 @@ +/* + * 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.jackrabbit.oak.plugins.document.util; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.math.DoubleMath; +import org.apache.jackrabbit.oak.cache.CacheStats; +import org.apache.jackrabbit.oak.plugins.document.Collection; +import org.apache.jackrabbit.oak.plugins.document.Document; +import org.apache.jackrabbit.oak.plugins.document.ThrottlingMetrics; +import org.apache.jackrabbit.oak.plugins.document.UpdateOp; +import org.apache.jackrabbit.oak.plugins.document.DocumentStore; +import org.apache.jackrabbit.oak.plugins.document.DocumentStoreException; +import org.apache.jackrabbit.oak.plugins.document.cache.CacheInvalidationStats; +import org.jetbrains.annotations.NotNull; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.List; +import java.util.Map; + +import static java.lang.Thread.sleep; + +/** + * Wrapper of another DocumentStore that does a throttling check on any method + * invocation (create or update) and throttled the system if under high load. + * <p> + * TODO update issue + * @see "https://issues.apache.org/jira/browse/OAK-2739 for more details" + */ +public class ThrottlingDocumentStoreWrapper implements DocumentStore { + + private static final Logger LOG = LoggerFactory.getLogger(ThrottlingDocumentStoreWrapper.class); + + @NotNull + private final DocumentStore store; + public ThrottlingDocumentStoreWrapper(final @NotNull DocumentStore store) { + this.store = store; + } + + @Override + public <T extends Document> T find(final Collection<T> collection, final String key) { + return store.find(collection, key); + } + + @Override + public <T extends Document> T find(final Collection<T> collection, final String key, + final int maxCacheAge) { + return store.find(collection, key, maxCacheAge); + } + + @NotNull + @Override + public <T extends Document> List<T> query(final Collection<T> collection, final String fromKey, + final String toKey, final int limit) { + return store.query(collection, fromKey, toKey, limit); + } + + @Override + @NotNull + public <T extends Document> List<T> query(final Collection<T> collection, final String fromKey, + final String toKey, final String indexedProperty, + final long startValue, final int limit) { + return store.query(collection, fromKey, toKey, indexedProperty, startValue, limit); + } + + @Override + public <T extends Document> void remove(Collection<T> collection, String key) { + performThrottling(); + store.remove(collection, key); + } + + @Override + public <T extends Document> void remove(Collection<T> collection, List<String> keys) { + performThrottling(); + store.remove(collection, keys); + } + + @Override + public <T extends Document> int remove(final Collection<T> collection, final Map<String, Long> toRemove) { + performThrottling(); + return store.remove(collection, toRemove); + } + + @Override + public <T extends Document> int remove(final Collection<T> collection, final String indexedProperty, + final long startValue, final long endValue) throws DocumentStoreException { + performThrottling(); + return store.remove(collection, indexedProperty, startValue, endValue); + } + + @Override + public <T extends Document> boolean create(final Collection<T> collection, final List<UpdateOp> updateOps) { + performThrottling(); + return store.create(collection, updateOps); + } + + @Override + public <T extends Document> T createOrUpdate(final Collection<T> collection, final UpdateOp update) { + performThrottling(); + return store.createOrUpdate(collection, update); + } + + @Override + public <T extends Document> List<T> createOrUpdate(final Collection<T> collection, final List<UpdateOp> updateOps) { + performThrottling(); + return store.createOrUpdate(collection, updateOps); + } + + @Override + public <T extends Document> T findAndUpdate(final Collection<T> collection, final UpdateOp update) { + performThrottling(); + return store.findAndUpdate(collection, update); + } + + @Override + public CacheInvalidationStats invalidateCache() { + return store.invalidateCache(); + } + + @Override + public CacheInvalidationStats invalidateCache(Iterable<String> keys) { + return store.invalidateCache(keys); + } + + @Override + public <T extends Document> void invalidateCache(Collection<T> collection, String key) { + store.invalidateCache(collection, key); + } + + @Override + public void dispose() { + store.dispose(); + } + + @Override + public <T extends Document> T getIfCached(final Collection<T> collection, final String key) { + return store.getIfCached(collection, key); + } + + @Override + public void setReadWriteMode(String readWriteMode) { + store.setReadWriteMode(readWriteMode); + } + + @Override + public Iterable<CacheStats> getCacheStats() { + return store.getCacheStats(); + } + + @Override + public Map<String, String> getMetadata() { + return store.getMetadata(); + } + + @NotNull + @Override + public Map<String, String> getStats() { + return store.getStats(); + } + + @Override + public long determineServerTimeDifferenceMillis() { + return store.determineServerTimeDifferenceMillis(); + } + + /** + * Return the size limit for node name based on the document store implementation + * + * @return node name size limit + */ + @Override + public int getNodeNameLimit() { + return store.getNodeNameLimit(); + } + + /** + * Return the @{@link ThrottlingMetrics} for the underlying document store + * + * @return throttling metric for document store + */ + @Override + public ThrottlingMetrics throttlingMetrics() { + return store.throttlingMetrics(); + } + + // helper methods + + private void performThrottling() { + + final ThrottlingMetrics metrics = throttlingMetrics(); + long throttleTime = getThrottleTime(metrics); + + if (throttleTime == 0) { + return; // no throttling + } + + try { + LOG.info("Throttling the system for {} ms", throttleTime); + sleep(throttleTime); + } catch (InterruptedException e) { + // swallow the exception and log it + LOG.error("Error while throttling", e); + } + } + + @VisibleForTesting + long getThrottleTime(final ThrottlingMetrics metrics) { + + long throttleTime = metrics.throttlingTime(); + final double threshold = metrics.threshold(); + final double currValue = metrics.currValue(); + + if (DoubleMath.fuzzyCompare(currValue,threshold/8, 0.001) <= 0) { + throttleTime = throttleTime * 8; + } else if (DoubleMath.fuzzyCompare(currValue,threshold/4, 0.001) <= 0) { + throttleTime = throttleTime * 4; + } else if (DoubleMath.fuzzyCompare(currValue, threshold/2, 0.001) <= 0) { + throttleTime = throttleTime * 2; + } else if (DoubleMath.fuzzyCompare(currValue, threshold,0.001) <= 0) { + throttleTime = metrics.throttlingTime(); Review Comment: OK, I see. Somehow I was confused by the threshold with the comparison. What is the reason for not using `Double.compare()` instead? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
