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POHow to safely close an IndexReader?
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  1. POHow to safely close an IndexReader?
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    copied!<p>My question is very simple, When use <code>IndexReader.openIfChanged (reader)</code> replace the previous <code>reader</code>, How to safely the close <code>oldReader</code>?</p> <p>Here is the code: (Use Lucene 3.5)</p> <pre><code>IndexReader newReader=IndexReader.openIfChanged(reader); if(newReader!=null){ IndexReader oldReader=reader; IndexSearcher oldSearcher=searcher; reader=newReader; searcher=new IndexSearcher(newReader); oldSearcher.close(); oldReader.close();//or oldReader.decRef(),result is the same } </code></pre> <p>This code in a deamon thread,Every 5 seconds run time</p> <p><code>IndexReader</code> instance(<code>reader</code> object) is globally unique</p> <p>Since this change, I get an exception:</p> <pre><code>org.apache.lucene.store.AlreadyClosedException: this IndexReader is closed at org.apache.lucene.index.IndexReader.ensureOpen(IndexReader.java:297) at org.apache.lucene.index.IndexReader.getSequentialSubReaders(IndexReader.java:1622) at org.apache.lucene.search.TermQuery$TermWeight.scorer(TermQuery.java:98) at org.apache.lucene.search.BooleanQuery$BooleanWeight.scorer(BooleanQuery.java:298) at org.apache.lucene.search.BooleanQuery$BooleanWeight.scorer(BooleanQuery.java:298) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:577) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:517) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:487) at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:400) at org.zenofo.index.IndexManager.query(IndexManager.java:392) ... </code></pre> <p><code>IndexManager.java:392</code> using the <code>reader</code> object(<code>IndexReader</code> instance,globally unique)</p> <p><code>IndexManager.query</code> method has a large number of concurrent requests, all requests to use a globally unique <code>IndexReader</code> instance (<code>reader</code> object)</p> <p><img src="https://i.stack.imgur.com/AQiRT.gif" alt="enter image description here"></p> <p>I need to close <code>oldReader</code> just because:</p> <ul> <li><a href="https://stackoverflow.com/questions/8224413/too-many-open-files-in-lucene-indexing-when-number-of-users-increase">Too many open files in Lucene Indexing when number of users increase</a></li> <li><a href="http://wiki.apache.org/lucene-java/LuceneFAQ#Why_am_I_getting_an_IOException_that_says_.22Too_many_open_files.22.3F" rel="nofollow noreferrer">Lucene Wiki:Too many open files</a></li> </ul> <p>Reference:</p> <ul> <li><a href="http://lucene.apache.org/core/3_6_0/api/all/index.html?org/apache/lucene/index/IndexReader.html" rel="nofollow noreferrer">API-IndexReader</a></li> <li><a href="http://lucene.apache.org/core/3_6_0/api/all/index.html?org/apache/lucene/search/IndexSearcher.html" rel="nofollow noreferrer">API-IndexSearcher</a></li> </ul> <p>How do I solve this problem?</p>
 

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