Langsame Antwortzeiten und hohe Heap-Auslastung aufgrund von Volltextsuche

"192.168.1.50 [1488891244417] GET /content/geometrixx/en.html HTTP/1.1" #125856 prio=5 os_prio=0 tid=0x00007f32fd3e7800 nid=0x4eb9 runnable [0x00007f3287b64000]
java.lang.Thread.State: RUNNABLE
at java.lang.System.identityHashCode(Native Method)
at org.apache.lucene.index.IndexReader.hashCode(IndexReader.java:290)
at java.util.WeakHashMap.hash(WeakHashMap.java:298)
at java.util.WeakHashMap.put(WeakHashMap.java:449)
at java.util.Collections$SetFromMap.add(Collections.java:5461)
at java.util.Collections$SynchronizedCollection.add(Collections.java:2035)
- locked <0x000000031c1174e8> (a java.util.Collections$SynchronizedSet)
at org.apache.lucene.index.IndexReader.registerParentReader(IndexReader.java:128)
at org.apache.lucene.index.FilterAtomicReader.<init>(FilterAtomicReader.java:334)
at org.apache.lucene.search.highlight.WeightedSpanTermExtractor$DelegatingAtomicReader.<init>(WeightedSpanTermExtractor.java:378)
at org.apache.lucene.search.highlight.WeightedSpanTermExtractor.getLeafContext(WeightedSpanTermExtractor.java:364)
at org.apache.lucene.search.highlight.WeightedSpanTermExtractor.extract(WeightedSpanTermExtractor.java:216)
at org.apache.lucene.search.highlight.WeightedSpanTermExtractor.extract(WeightedSpanTermExtractor.java:99)
at org.apache.lucene.search.highlight.WeightedSpanTermExtractor.getWeightedSpanTerms(WeightedSpanTermExtractor.java:474)
at org.apache.lucene.search.highlight.QueryScorer.initExtractor(QueryScorer.java:217)
at org.apache.lucene.search.highlight.QueryScorer.init(QueryScorer.java:186)
at org.apache.lucene.search.highlight.Highlighter.getBestTextFragments(Highlighter.java:197)
at org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndex.getExcerpt(LuceneIndex.java:496)
at org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndex.access$300(LuceneIndex.java:152)
at org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndex$1.loadDocs(LuceneIndex.java:369)
at org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndex$1.computeNext(LuceneIndex.java:293)
at org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndex$1.computeNext(LuceneIndex.java:283)
at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
at org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndex$LucenePathCursor$1.hasNext(LuceneIndex.java:1116)
at com.google.common.collect.Iterators$7.computeNext(Iterators.java:645)
at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
at org.apache.jackrabbit.oak.spi.query.Cursors$PathCursor.hasNext(Cursors.java:205)
at org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndex$LucenePathCursor.hasNext(LuceneIndex.java:1137)
at org.apache.jackrabbit.oak.plugins.index.aggregate.AggregationCursor.fetchNext(AggregationCursor.java:89)
at org.apache.jackrabbit.oak.plugins.index.aggregate.AggregationCursor.hasNext(AggregationCursor.java:76)
at org.apache.jackrabbit.oak.spi.query.Cursors$IntersectionCursor.fetchNext(Cursors.java:402)
at org.apache.jackrabbit.oak.spi.query.Cursors$IntersectionCursor.hasNext(Cursors.java:394)
at org.apache.jackrabbit.oak.spi.query.Cursors$IntersectionCursor.fetchNext(Cursors.java:402)
at org.apache.jackrabbit.oak.spi.query.Cursors$IntersectionCursor.hasNext(Cursors.java:394)
at org.apache.jackrabbit.oak.query.ast.SelectorImpl.next(SelectorImpl.java:407)
at org.apache.jackrabbit.oak.query.QueryImpl$RowIterator.fetchNext(QueryImpl.java:773)
at org.apache.jackrabbit.oak.query.QueryImpl$RowIterator.hasNext(QueryImpl.java:798)
at com.google.common.collect.Iterators$5.hasNext(Iterators.java:542)
at org.apache.jackrabbit.oak.query.FilterIterators$DistinctIterator.fetchNext(FilterIterators.java:137)
at org.apache.jackrabbit.oak.query.FilterIterators$DistinctIterator.hasNext(FilterIterators.java:151)
at org.apache.jackrabbit.oak.jcr.query.QueryResultImpl$1.fetch(QueryResultImpl.java:108)
at org.apache.jackrabbit.oak.jcr.query.QueryResultImpl$1.<init>(QueryResultImpl.java:104)
at org.apache.jackrabbit.oak.jcr.query.QueryResultImpl.getRows(QueryResultImpl.java:91)
at com.day.cq.search.impl.builder.QueryImpl.execute(QueryImpl.java:475)
at com.day.cq.search.impl.builder.QueryImpl.getResult(QueryImpl.java:106)
at com.day.cq.search.impl.SimpleSearchImpl.getResult(SimpleSearchImpl.java:179)
at com.day.cq.wcm.foundation.Search.getResult(Search.java:219)