this hack is the occurrence of Exceptions like:
W 2014/02/11 18:51:33 ConcurrentLog GC overhead limit exceeded
java.io.IOException: GC overhead limit exceeded
at
net.yacy.cora.federate.solr.connector.AbstractSolrConnector.getDocumentById(AbstractSolrConnector.java:334)
at
net.yacy.cora.federate.solr.connector.MirrorSolrConnector.getDocumentById(MirrorSolrConnector.java:173)
at
net.yacy.cora.federate.solr.connector.ConcurrentUpdateSolrConnector.getDocumentById(ConcurrentUpdateSolrConnector.java:415)
at net.yacy.search.index.Fulltext.getMetadata(Fulltext.java:331)
at net.yacy.search.index.Fulltext.getMetadata(Fulltext.java:317)
at
net.yacy.search.query.SearchEvent.pullOneRWI(SearchEvent.java:1024)
at
net.yacy.search.query.SearchEvent.pullOneFilteredFromRWI(SearchEvent.java:1047)
at
net.yacy.search.query.SearchEvent$3.run(SearchEvent.java:1263)
Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded
at java.util.Arrays.copyOfRange(Arrays.java:3077)
at java.lang.StringCoding.decode(StringCoding.java:196)
at java.lang.String.<init>(String.java:491)
at java.lang.String.<init>(String.java:547)
at
org.apache.lucene.codecs.compressing.CompressingStoredFieldsReader.readField(CompressingStoredFieldsReader.java:187)
at
org.apache.lucene.codecs.compressing.CompressingStoredFieldsReader.visitDocument(CompressingStoredFieldsReader.java:351)
at
org.apache.lucene.index.SegmentReader.document(SegmentReader.java:276)
at
org.apache.lucene.index.BaseCompositeReader.document(BaseCompositeReader.java:110)
at
org.apache.lucene.index.IndexReader.document(IndexReader.java:436)
at
org.apache.solr.search.SolrIndexSearcher.doc(SolrIndexSearcher.java:657)
at
net.yacy.cora.federate.solr.connector.EmbeddedSolrConnector.SolrQueryResponse2SolrDocumentList(EmbeddedSolrConnector.java:230)
at
net.yacy.cora.federate.solr.connector.EmbeddedSolrConnector.getDocumentListByParams(EmbeddedSolrConnector.java:320)
at
net.yacy.cora.federate.solr.connector.AbstractSolrConnector.getDocumentById(AbstractSolrConnector.java:330)
... 7 more
This problem was analysed with the Eclipse Memory Analyser after a heap
dump, where the following problem was reported as the main Problem
Suspect:
One instance of "org.apache.solr.util.ConcurrentLRUCache" loaded by
"sun.misc.Launcher$AppClassLoader @ 0x42e940a0" occupies 902.898.256
(61,80%) bytes. The memory is accumulated in one instance of
"java.util.concurrent.ConcurrentHashMap$Segment[]" loaded by "<system
class loader>".
This memory is part of the result cache of Solr. Flushing this cache
appears the most appropriate solution to that problem.
orbiter
14764632b5