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https://issues.apache.org/jira/browse/OAK-9184?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Thomas Mueller resolved OAK-9184.
---------------------------------
Resolution: Fixed
> Very slow, potential endless loop in LucenePropertyIndex.loadDocs()
> -------------------------------------------------------------------
>
> Key: OAK-9184
> URL: https://issues.apache.org/jira/browse/OAK-9184
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: lucene
> Affects Versions: 1.22.4, 1.32.0, 1.8.23
> Reporter: Thomas Mueller
> Assignee: Thomas Mueller
> Priority: Major
> Fix For: 1.34.0, 1.22.5, 1.8.24
>
>
> We found one case of a very slow, possibly endless loop in this method.
> {noformat}
> java.lang.Thread.State: RUNNABLE at
> org.apache.lucene.search.TopScoreDocCollector$InOrderPagingScoreDocCollector.collect(TopScoreDocCollector.java:85)
> at org.apache.lucene.search.Scorer.score(Scorer.java:65) at
> org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:621) at
> org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:491) at
> org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:448) at
> org.apache.lucene.search.IndexSearcher.searchAfter(IndexSearcher.java:243) at
> org.apache.jackrabbit.oak.plugins.index.lucene.LucenePropertyIndex$1.loadDocs(LucenePropertyIndex.java:434)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.LucenePropertyIndex$1.computeNext(LucenePropertyIndex.java:353)
> {noformat}
> Background: Many threads are waiting to lock here:
> {noformat}
> - waiting to lock <0x00007fbd804a9448> (a
> org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker.acquireIndexNode(IndexTracker.java:202)
> public IndexNode acquireIndexNode(String path) {
> IndexNodeManager index = indices.get(path);
> IndexNode indexNode = index != null ? index.acquire() : null;
> if (indexNode != null) {
> return indexNode;
> } else {
> return findIndexNode(path); <<= synchronized method
> }
> }
> {noformat}
> And the thread that is holding that (synchronized) lock on IndexTracker is
> also waiting to get a write lock here:
> {noformat}
> "oak-lucene-992" #21559 daemon prio=1 os_prio=0 tid=0x00007ed0280ad000
> nid=0x1be8 waiting on condition [0x00007fb96c352000]
> java.lang.Thread.State: WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> - parking to wait for <0x00007fbedad77210> (a
> java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync)
> at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
> at
> java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.lock(ReentrantReadWriteLock.java:943)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.IndexNodeManager.close(IndexNodeManager.java:174)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker.close(IndexTracker.java:104)
> - locked <0x00007fbd804a9448> (a
> org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker.update(IndexTracker.java:114)
> - locked <0x00007fbd804a9448> (a
> org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker)
> void close() throws IOException {
> lock.writeLock().lock(); <<== waiting here
> try {
> checkState(!closed);
> closed = true;
> } finally {
> lock.writeLock().unlock();
> }
> {noformat}
> It looks like a read lock is not released. The places where a read lock is
> acquired:
> {noformat}
> IndexNode acquire() {
> lock.readLock().lock();
> (released if the method returns null or throws an exception)
> private void release() {
> lock.readLock().unlock();
> }
> {noformat}
> acquire() is called in acquireIndexNode:
> {noformat}
> public IndexNode acquireIndexNode(String path) {
> IndexNodeManager index = indices.get(path);
> IndexNode indexNode = index != null ? index.acquire() : null; <<==
> here
> if (indexNode != null) {
> return indexNode;
> } else {
> return findIndexNode(path);
> }
> }
> private synchronized IndexNode findIndexNode(String path) {
> // Retry the lookup from acquireIndexNode now that we're
> // synchronized. The acquire() call is guaranteed to succeed
> // since the close() method is also synchronized.
> IndexNodeManager index = indices.get(path);
> if (index != null) {
> IndexNode indexNode = index.acquire(); <<== here
> return checkNotNull(indexNode);
> }
> {noformat}
> This method is called in multiple places (getPlanDescription, getPlans,
> loadDocs, getSize, getOldFullTextIndexPath, dumpIndexContent, getFieldInfo,
> getFieldTermPrefixInfo, getIndexedPaths, getIndexStats) but always released
> in "finally".
> There is one thread that seems to hold this read lock:
> {noformat}
> "10.13.0.73 [1597750655085] GET
> /mnt/overlay/granite/ui/content/shell/omnisearch/searchresults.html HTTP/1.1"
> #10953 prio=5 os_prio=0 tid=0x00007fb97000f000 nid=0x8b59 runnable
> [0x00007fb96c44c000]
> java.lang.Thread.State: RUNNABLE
> at
> org.apache.lucene.search.TopScoreDocCollector$InOrderPagingScoreDocCollector.collect(TopScoreDocCollector.java:85)
> at org.apache.lucene.search.Scorer.score(Scorer.java:65)
> at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:621)
> at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:491)
> at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:448)
> at
> org.apache.lucene.search.IndexSearcher.searchAfter(IndexSearcher.java:243)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.LucenePropertyIndex$1.loadDocs(LucenePropertyIndex.java:434)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.LucenePropertyIndex$1.computeNext(LucenePropertyIndex.java:353)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.LucenePropertyIndex$1.computeNext(LucenePropertyIndex.java:339)
> at
> com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
> at
> com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.LucenePropertyIndex$LucenePathCursor$1.hasNext(LucenePropertyIndex.java:1718)
> at com.google.common.collect.Iterators$7.computeNext(Iterators.java:645)
> at
> com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
> at
> com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
> at
> org.apache.jackrabbit.oak.plugins.index.Cursors$PathCursor.hasNext(Cursors.java:216)
> at
> org.apache.jackrabbit.oak.plugins.index.lucene.LucenePropertyIndex$LucenePathCursor.hasNext(LucenePropertyIndex.java:1751)
> at
> org.apache.jackrabbit.oak.query.ast.SelectorImpl.next(SelectorImpl.java:432)
> at
> org.apache.jackrabbit.oak.query.QueryImpl$RowIterator.fetchNext(QueryImpl.java:824)
> at
> org.apache.jackrabbit.oak.query.QueryImpl$RowIterator.hasNext(QueryImpl.java:851)
> at com.google.common.collect.Iterators$5.hasNext(Iterators.java:542)
> at
> org.apache.jackrabbit.oak.query.FilterIterators$DistinctIterator.fetchNext(FilterIterators.java:141)
> at
> org.apache.jackrabbit.oak.query.FilterIterators$DistinctIterator.hasNext(FilterIterators.java:155)
> at
> org.apache.jackrabbit.oak.jcr.query.QueryResultImpl$1.fetch(QueryResultImpl.java:98)
> at
> org.apache.jackrabbit.oak.jcr.query.QueryResultImpl$1.next(QueryResultImpl.java:123)
> at
> org.apache.jackrabbit.oak.jcr.query.QueryResultImpl$1.next(QueryResultImpl.java:78)
> at
> org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate$SynchronizedIterator.next(SessionDelegate.java:702)
> at
> org.apache.jackrabbit.oak.jcr.query.PrefetchIterator.size(PrefetchIterator.java:135)
> at
> org.apache.jackrabbit.oak.jcr.query.QueryResultImpl$3.getSize(QueryResultImpl.java:143)
> at
> org.apache.jackrabbit.oak.jcr.query.QueryResultImpl.getRows(QueryResultImpl.java:140)
> {noformat}
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