| /* |
| * 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; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.apache.jackrabbit.oak.plugins.document.util.Utils; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import com.google.common.base.Stopwatch; |
| |
| import static java.util.concurrent.TimeUnit.MILLISECONDS; |
| import static org.apache.jackrabbit.oak.plugins.document.Collection.SETTINGS; |
| |
| /** |
| * The JournalGarbageCollector can clean up JournalEntries that are older than a |
| * particular age. |
| * <p> |
| * It would typically be invoked in conjunction with the VersionGarbageCollector |
| * but must not be confused with that one - 'journal' refers to the separate |
| * collection that contains changed paths per background writes used for |
| * observation. |
| */ |
| public class JournalGarbageCollector { |
| |
| private static final Logger log = LoggerFactory.getLogger(JournalGarbageCollector.class); |
| |
| /** |
| * ID of the journalGC document in the settings collection. |
| */ |
| private static final String JOURNAL_GC_ID = "journalGC"; |
| |
| /** |
| * Key name of the entry that contains the timestamp of the journal tail. |
| */ |
| private static final String TAIL_TIMESTAMP = "tailTimestamp"; |
| |
| private final DocumentNodeStore ns; |
| |
| private final long maxRevisionAgeMillis; |
| |
| private volatile long lastTailTimestampRefresh = Long.MIN_VALUE; |
| |
| private Revision tailRevision; |
| |
| public JournalGarbageCollector(DocumentNodeStore nodeStore, |
| long maxRevisionAgeMillis) { |
| this.ns = nodeStore; |
| this.maxRevisionAgeMillis = maxRevisionAgeMillis; |
| this.tailRevision = new Revision(0, 0, ns.getClusterId()); |
| } |
| |
| /** |
| * Deletes entries in the journal that are older than |
| * {@link #getMaxRevisionAgeMillis()}. |
| * |
| * @return the number of entries that have been removed |
| */ |
| public int gc() { |
| DocumentStore ds = ns.getDocumentStore(); |
| Revision checkpointRev = ns.getCheckpoints().getOldestRevisionToKeep(); |
| Long keep = null; |
| if (checkpointRev != null) { |
| // keep more entries than just up to the checkpoint to account |
| // for branch commits that may be referenced by merge commits |
| keep = checkpointRev.getTimestamp() - maxRevisionAgeMillis / 2; |
| } |
| long now = ns.getClock().getTime(); |
| long gcOlderThan = now - maxRevisionAgeMillis; |
| if (keep != null && keep < gcOlderThan) { |
| gcOlderThan = keep; |
| log.debug("gc: Checkpoint {} is older than maxRevisionAge: {} min", |
| keep, MILLISECONDS.toMinutes(maxRevisionAgeMillis)); |
| } |
| if (log.isDebugEnabled()) { |
| log.debug("gc: Journal garbage collection starts with maxAge: {} min.", |
| MILLISECONDS.toMinutes(maxRevisionAgeMillis)); |
| } |
| Stopwatch sw = Stopwatch.createStarted(); |
| |
| // update the tail timestamp in the journalGC document |
| // of the settings collection |
| updateTailTimestamp(gcOlderThan); |
| |
| int numDeleted = ds.remove(Collection.JOURNAL, JournalEntry.MODIFIED, 0, gcOlderThan); |
| |
| sw.stop(); |
| |
| if (numDeleted > 0) { |
| log.info("gc: Journal garbage collection took {}, deleted {} entries that were older than {} min.", |
| sw, numDeleted, MILLISECONDS.toMinutes(now - gcOlderThan)); |
| } |
| return numDeleted; |
| } |
| |
| private void updateTailTimestamp(long gcOlderThan) { |
| UpdateOp op = new UpdateOp(JOURNAL_GC_ID, true); |
| op.max(TAIL_TIMESTAMP, gcOlderThan); |
| ns.getDocumentStore().createOrUpdate(SETTINGS, op); |
| } |
| |
| public Revision getTailRevision() { |
| refreshTailRevisionIfNecessary(); |
| return tailRevision; |
| } |
| |
| long getMaxRevisionAgeMillis() { |
| return maxRevisionAgeMillis; |
| } |
| |
| private void refreshTailRevisionIfNecessary() { |
| // refresh once a minute |
| long now = ns.getClock().getTime(); |
| if (lastTailTimestampRefresh + TimeUnit.MINUTES.toMillis(1) > now) { |
| return; |
| } |
| lastTailTimestampRefresh = now; |
| |
| Document doc = ns.getDocumentStore().find(SETTINGS, JOURNAL_GC_ID); |
| if (doc == null) { |
| // no gc yet |
| return; |
| } |
| Long ts = Utils.asLong((Number) doc.get(TAIL_TIMESTAMP)); |
| if (ts != null) { |
| tailRevision = Utils.max(tailRevision, new Revision(ts, 0, ns.getClusterId())); |
| } |
| } |
| |
| private List<String> asKeys(List<JournalEntry> deletionBatch) { |
| final List<String> keys = new ArrayList<String>(deletionBatch.size()); |
| for (JournalEntry e : deletionBatch) { |
| keys.add(e.getId()); |
| } |
| return keys; |
| } |
| |
| } |