[LUCENE-3409] NRT reader/writer over RAMDirectory memory leak

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.2, 3.3, 4.0-ALPHA
• Fix Version/s: 3.4, 4.0-ALPHA
• Component/s: core/index
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: tal steier
• Created: 31/Aug/11 08:45
• Updated: 27/Nov/11 12:31
• Resolved: 31/Aug/11 12:09

Description

with NRT reader/writer, emptying an index using:
writer.deleteAll()
writer.commit()
doesn't release all allocated memory.

for example the following code will generate a memory leak:

/**

• Reveals a memory leak in NRT reader/writer<br>
• The following main() does 10K cycles of:
• <ul>
• <li>Add 10K empty documents to index writer</li>
• <li>commit()</li>
• <li>open NRT reader over the writer, and immediately close it</li>
• <li>delete all documents from the writer</li>
• <li>commit changes to the writer</li>
• </ul>
• Running with -Xmx256M results in an OOME after ~2600 cycles
  */
  public static void main(String[] args) throws Exception {
  RAMDirectory d = new RAMDirectory();
  IndexWriter w = new IndexWriter(d, new IndexWriterConfig(Version.LUCENE_33, new KeywordAnalyzer()));
  Document doc = new Document();

for(int i = 0; i < 10000; i++) {
for(int j = 0; j < 10000; ++j)

{ w.addDocument(doc); }

w.commit();
IndexReader.open(w, true).close();

w.deleteAll();
w.commit();
}

w.close();
d.close();
}