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Andy Seaborne closed JENA-848. ------------------------------ Close resolved issue on release of Jena 2.13.0. > jena-text Lucene concurrency issues > ----------------------------------- > > Key: JENA-848 > URL: https://issues.apache.org/jira/browse/JENA-848 > Project: Apache Jena > Issue Type: Bug > Components: Text > Reporter: Stephen Allen > Assignee: Stephen Allen > > When using jena-text with an in-process Lucene index, there are concurrency > issues when multiple requests are accessing the Dataset in using transactions. > It appears the problem is that a new Lucene IndexWriter is created at every > transaction start with no concurrency control. Instead the solution should > be to create a single IndexWriter when the DatasetGraphText is created and > use that for all requests. This works because the Lucene IndexWriter is > thread safe and designed for concurrent access. > This should also increase performance by not continually opening and closing > the IndexWriter. Also we can use Near Real-Time (NRT) IndexReaders that > don't have to wait until changes are pushed to disk. > If concurrent access is not controlled then you can end up with IndexWriter > objects being closed while they are still in use by other threads: > {code} > org.apache.lucene.store.AlreadyClosedException: this IndexWriter is closed > at > org.apache.lucene.index.IndexWriter.ensureOpen(IndexWriter.java:645) > at > org.apache.lucene.index.IndexWriter.commitInternal(IndexWriter.java:2974) > at org.apache.lucene.index.IndexWriter.commit(IndexWriter.java:2954) > at > org.apache.jena.query.text.TextIndexLucene.finishIndexing(TextIndexLucene.java:122) > at > org.apache.jena.query.text.TextDocProducerTriples.finish(TextDocProducerTriples.java:46) > at > org.apache.jena.query.text.DatasetGraphText.commit(DatasetGraphText.java:122) > at > org.apache.jena.query.text.TestLuceneWithMultipleThreads$2.run(TestLuceneWithMultipleThreads.java:156) > at > java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) > at java.util.concurrent.FutureTask.run(FutureTask.java:266) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) > at java.lang.Thread.run(Thread.java:744) > {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332)