LUCENE-992: move buffered deletes into DocumentsWriter so IndexWriter.updateDocument is atomic

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@574260 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -83,6 +83,9 @@ Bug fixes
 
 13. LUCENE-991: The explain() method of BoostingTermQuery had errors when no payloads were present on a document.  (Peter Keegan via Grant Ingersoll)
 
+14. LUCENE-992: Fixed IndexWriter.updateDocument to be atomic again
+    (this was broken by LUCENE-843).  (Ning Li via Mike McCandless)
+
 New features
 
  1. LUCENE-906: Elision filter for French.

src/java/org/apache/lucene/index/DocumentsWriter.java

@@ -129,6 +129,16 @@ final class DocumentsWriter {
 
   private PrintStream infoStream;
 
+  // This Hashmap buffers delete terms in ram before they
+  // are applied.  The key is delete term; the value is
+  // number of buffered documents the term applies to.
+  private HashMap bufferedDeleteTerms = new HashMap();
+  private int numBufferedDeleteTerms = 0;
+
+  // The max number of delete terms that can be buffered before
+  // they must be flushed to disk.
+  private int maxBufferedDeleteTerms = IndexWriter.DEFAULT_MAX_BUFFERED_DELETE_TERMS;
+
   // How much RAM we can use before flushing.  This is 0 if
   // we are flushing by doc count instead.
   private long ramBufferSize = (long) (IndexWriter.DEFAULT_RAM_BUFFER_SIZE_MB*1024*1024);
@@ -265,8 +275,8 @@ final class DocumentsWriter {
 
   /** Called if we hit an exception when adding docs,
    *  flushing, etc.  This resets our state, discarding any
-   *  * docs added since last flush. */
+   *  docs added since last flush. */
-  void abort() throws IOException {
+  synchronized void abort() throws IOException {
 
     // Forcefully remove waiting ThreadStates from line
     for(int i=0;i<numWaiting;i++)
@@ -275,6 +285,9 @@ final class DocumentsWriter {
 
     pauseAllThreads();
 
+    bufferedDeleteTerms.clear();
+    numBufferedDeleteTerms = 0;
+
     try {
 
       // Discard pending norms:
@@ -2063,8 +2076,10 @@ final class DocumentsWriter {
 
   /** Returns a free (idle) ThreadState that may be used for
    * indexing this one document.  This call also pauses if a
-   * flush is pending. */
+   * flush is pending.  If delTerm is non-null then we
-  synchronized ThreadState getThreadState(Document doc) throws IOException {
+   * buffer this deleted term after the thread state has
+   * been acquired. */
+  synchronized ThreadState getThreadState(Document doc, Term delTerm) throws IOException {
 
     // First, find a thread state.  If this thread already
     // has affinity to a specific ThreadState, use that one
@@ -2134,6 +2149,9 @@ final class DocumentsWriter {
       }
     }
 
+    if (delTerm != null)
+      addDeleteTerm(delTerm, state.docID);
+
     return state;
   }
 
@@ -2141,9 +2159,19 @@ final class DocumentsWriter {
    * flush. */
   boolean addDocument(Document doc, Analyzer analyzer)
     throws CorruptIndexException, IOException {
+    return updateDocument(doc, analyzer, null);
+  }
+
+  boolean updateDocument(Term t, Document doc, Analyzer analyzer)
+    throws CorruptIndexException, IOException {
+    return updateDocument(doc, analyzer, t);
+  }
+
+  boolean updateDocument(Document doc, Analyzer analyzer, Term delTerm)
+    throws CorruptIndexException, IOException {
 
     // This call is synchronized but fast
-    final ThreadState state = getThreadState(doc);
+    final ThreadState state = getThreadState(doc, delTerm);
     boolean success = false;
     try {
       // This call is not synchronized and does all the work
@@ -2157,7 +2185,96 @@ final class DocumentsWriter {
         abort();
       }
     }
-    return state.doFlushAfter;
+    return state.doFlushAfter || timeToFlushDeletes();
+  }
+
+  synchronized int getNumBufferedDeleteTerms() {
+    return numBufferedDeleteTerms;
+  }
+
+  synchronized HashMap getBufferedDeleteTerms() {
+    return bufferedDeleteTerms;
+  }
+
+  // Reset buffered deletes.
+  synchronized void clearBufferedDeleteTerms() {
+    bufferedDeleteTerms.clear();
+    numBufferedDeleteTerms = 0;
+  }
+
+  synchronized boolean bufferDeleteTerms(Term[] terms) throws IOException {
+    while(pauseThreads != 0 || flushPending)
+      try {
+        wait();
+      } catch (InterruptedException e) {}
+      for (int i = 0; i < terms.length; i++)
+        addDeleteTerm(terms[i], numDocsInRAM);
+    return timeToFlushDeletes();
+  }
+
+  synchronized boolean bufferDeleteTerm(Term term) throws IOException {
+    while(pauseThreads != 0 || flushPending)
+      try {
+        wait();
+      } catch (InterruptedException e) {}
+    addDeleteTerm(term, numDocsInRAM);
+    return timeToFlushDeletes();
+  }
+
+  synchronized private boolean timeToFlushDeletes() {
+    return numBufferedDeleteTerms >= maxBufferedDeleteTerms && setFlushPending();
+  }
+
+  void setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms) {
+    if (maxBufferedDeleteTerms < 1)
+      throw new IllegalArgumentException("maxBufferedDeleteTerms must at least be 1");
+    this.maxBufferedDeleteTerms = maxBufferedDeleteTerms;
+  }
+
+  int getMaxBufferedDeleteTerms() {
+    return maxBufferedDeleteTerms;
+  }
+
+  synchronized boolean hasDeletes() {
+    return bufferedDeleteTerms.size() > 0;
+  }
+
+  // Number of documents a delete term applies to.
+  static class Num {
+    private int num;
+
+    Num(int num) {
+      this.num = num;
+    }
+
+    int getNum() {
+      return num;
+    }
+
+    void setNum(int num) {
+      // Only record the new number if it's greater than the
+      // current one.  This is important because if multiple
+      // threads are replacing the same doc at nearly the
+      // same time, it's possible that one thread that got a
+      // higher docID is scheduled before the other
+      // threads.
+      if (num > this.num)
+        this.num = num;
+    }
+  }
+
+  // Buffer a term in bufferedDeleteTerms, which records the
+  // current number of documents buffered in ram so that the
+  // delete term will be applied to those documents as well
+  // as the disk segments.
+  synchronized private void addDeleteTerm(Term term, int docCount) {
+    Num num = (Num) bufferedDeleteTerms.get(term);
+    if (num == null) {
+      bufferedDeleteTerms.put(term, new Num(docCount));
+    } else {
+      num.setNum(docCount);
+    }
+    numBufferedDeleteTerms++;
   }
 
   /** Does the synchronized work to finish/flush the

src/java/org/apache/lucene/index/IndexWriter.java

@@ -247,16 +247,6 @@ public class IndexWriter {
 
   private int termIndexInterval = DEFAULT_TERM_INDEX_INTERVAL;
 
-  // The max number of delete terms that can be buffered before
-  // they must be flushed to disk.
-  private int maxBufferedDeleteTerms = DEFAULT_MAX_BUFFERED_DELETE_TERMS;
-
-  // This Hashmap buffers delete terms in ram before they are applied.
-  // The key is delete term; the value is number of ram
-  // segments the term applies to.
-  private HashMap bufferedDeleteTerms = new HashMap();
-  private int numBufferedDeleteTerms = 0;
-
   /** Use compound file setting. Defaults to true, minimizing the number of
    * files used.  Setting this to false may improve indexing performance, but
    * may also cause file handle problems.
@@ -773,9 +763,7 @@ public class IndexWriter {
    */
   public void setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms) {
     ensureOpen();
-    if (maxBufferedDeleteTerms < 1)
+    docWriter.setMaxBufferedDeleteTerms(maxBufferedDeleteTerms);
-      throw new IllegalArgumentException("maxBufferedDeleteTerms must at least be 1");
-    this.maxBufferedDeleteTerms = maxBufferedDeleteTerms;
   }
 
   /**
@@ -785,7 +773,7 @@ public class IndexWriter {
    */
   public int getMaxBufferedDeleteTerms() {
     ensureOpen();
-    return maxBufferedDeleteTerms;
+    return docWriter.getMaxBufferedDeleteTerms();
   }
 
   /** Determines how often segment indices are merged by addDocument().  With
@@ -1134,10 +1122,11 @@ public class IndexWriter {
    * @throws CorruptIndexException if the index is corrupt
    * @throws IOException if there is a low-level IO error
    */
-  public synchronized void deleteDocuments(Term term) throws CorruptIndexException, IOException {
+  public void deleteDocuments(Term term) throws CorruptIndexException, IOException {
     ensureOpen();
-    bufferDeleteTerm(term);
+    boolean doFlush = docWriter.bufferDeleteTerm(term);
-    maybeFlush();
+    if (doFlush)
+      flush(true, false);
   }
 
   /**
@@ -1148,12 +1137,11 @@ public class IndexWriter {
    * @throws CorruptIndexException if the index is corrupt
    * @throws IOException if there is a low-level IO error
    */
-  public synchronized void deleteDocuments(Term[] terms) throws CorruptIndexException, IOException {
+  public void deleteDocuments(Term[] terms) throws CorruptIndexException, IOException {
     ensureOpen();
-    for (int i = 0; i < terms.length; i++) {
+    boolean doFlush = docWriter.bufferDeleteTerms(terms);
-      bufferDeleteTerm(terms[i]);
+    if (doFlush)
-    }
+      flush(true, false);
-    maybeFlush();
   }
 
   /**
@@ -1189,20 +1177,15 @@ public class IndexWriter {
   public void updateDocument(Term term, Document doc, Analyzer analyzer)
       throws CorruptIndexException, IOException {
     ensureOpen();
-    synchronized (this) {
+    boolean doFlush = false;
-      bufferDeleteTerm(term);
-    }
-    boolean success = false;
     try {
-      success = docWriter.addDocument(doc, analyzer);
+      doFlush = docWriter.updateDocument(term, doc, analyzer);
     } catch (IOException ioe) {
       deleter.refresh();
       throw ioe;
     }
-    if (success)
+    if (doFlush)
       flush(true, false);
-    else
-      maybeFlush();
   }
 
   // for test purpose
@@ -1357,7 +1340,7 @@ public class IndexWriter {
    */
   private void startTransaction() throws IOException {
 
-    assert numBufferedDeleteTerms == 0 :
+    assert docWriter.getNumBufferedDeleteTerms() == 0 :
            "calling startTransaction with buffered delete terms not supported";
     assert docWriter.getNumDocsInRAM() == 0 :
            "calling startTransaction with buffered documents not supported";
@@ -1462,9 +1445,6 @@ public class IndexWriter {
       deleter.checkpoint(segmentInfos, false);
       deleter.refresh();
 
-      bufferedDeleteTerms.clear();
-      numBufferedDeleteTerms = 0;
-
       commitPending = false;
       docWriter.abort();
       close();
@@ -1845,20 +1825,6 @@ public class IndexWriter {
     throws IOException {
   }
 
-  /**
-   * Used internally to trigger a flush if the number of
-   * buffered added documents or buffered deleted terms are
-   * large enough.
-   */
-  protected final synchronized void maybeFlush() throws CorruptIndexException, IOException {
-    // We only check for flush due to number of buffered
-    // delete terms, because triggering of a flush due to
-    // too many added documents is handled by
-    // DocumentsWriter
-    if (numBufferedDeleteTerms >= maxBufferedDeleteTerms && docWriter.setFlushPending())
-      flush(true, false);
-  }
-
   /**
    * Flush all in-memory buffered updates (adds and deletes)
    * to the Directory. 
@@ -1908,7 +1874,7 @@ public class IndexWriter {
       // when they are full or writer is being closed.  We
       // have to fix the "applyDeletesSelectively" logic to
       // apply to more than just the last flushed segment
-      boolean flushDeletes = bufferedDeleteTerms.size() > 0;
+      boolean flushDeletes = docWriter.hasDeletes();
 
       if (infoStream != null)
         infoStream.println("  flush: flushDocs=" + flushDocs +
@@ -1938,9 +1904,6 @@ public class IndexWriter {
 
         SegmentInfos rollback = null;
 
-        HashMap saveBufferedDeleteTerms = null;
-        int saveNumBufferedDeleteTerms = 0;
-
         if (flushDeletes)
           rollback = (SegmentInfos) segmentInfos.clone();
 
@@ -1975,9 +1938,9 @@ public class IndexWriter {
             // buffer deletes longer and then flush them to
             // multiple flushed segments, when
             // autoCommit=false
-            saveBufferedDeleteTerms = bufferedDeleteTerms;
+            int delCount = applyDeletes(flushDocs);
-            saveNumBufferedDeleteTerms = numBufferedDeleteTerms;
+            if (infoStream != null)
-            applyDeletes(flushDocs);
+              infoStream.println("flushed " + delCount + " deleted documents");
             doAfterFlush();
           }
 
@@ -1992,11 +1955,6 @@ public class IndexWriter {
               segmentInfos.clear();
               segmentInfos.addAll(rollback);
               
-              if (saveBufferedDeleteTerms != null) {
-                numBufferedDeleteTerms = saveNumBufferedDeleteTerms;
-                bufferedDeleteTerms = saveBufferedDeleteTerms;
-              }
-              
             } else {
               // Remove segment we added, if any:
               if (newSegment != null && 
@@ -2319,11 +2277,14 @@ public class IndexWriter {
   // flushedNewSegment is true then a new segment was just
   // created and flushed from the ram segments, so we will
   // selectively apply the deletes to that new segment.
-  private final void applyDeletes(boolean flushedNewSegment) throws CorruptIndexException, IOException {
+  private final int applyDeletes(boolean flushedNewSegment) throws CorruptIndexException, IOException {
 
+    final HashMap bufferedDeleteTerms = docWriter.getBufferedDeleteTerms();
+
+    int delCount = 0;
     if (bufferedDeleteTerms.size() > 0) {
       if (infoStream != null)
-        infoStream.println("flush " + numBufferedDeleteTerms + " buffered deleted terms on "
+        infoStream.println("flush " + docWriter.getNumBufferedDeleteTerms() + " buffered deleted terms on "
                            + segmentInfos.size() + " segments.");
 
       if (flushedNewSegment) {
@@ -2337,7 +2298,7 @@ public class IndexWriter {
           // Apply delete terms to the segment just flushed from ram
           // apply appropriately so that a delete term is only applied to
           // the documents buffered before it, not those buffered after it.
-          applyDeletesSelectively(bufferedDeleteTerms, reader);
+          delCount += applyDeletesSelectively(bufferedDeleteTerms, reader);
         } finally {
           if (reader != null) {
             try {
@@ -2361,7 +2322,7 @@ public class IndexWriter {
 
           // Apply delete terms to disk segments
           // except the one just flushed from ram.
-          applyDeletes(bufferedDeleteTerms, reader);
+          delCount += applyDeletes(bufferedDeleteTerms, reader);
         } finally {
           if (reader != null) {
             try {
@@ -2374,15 +2335,10 @@ public class IndexWriter {
       }
 
       // Clean up bufferedDeleteTerms.
-
+      docWriter.clearBufferedDeleteTerms();
-      // Rollbacks of buffered deletes are based on restoring the old
-      // map, so don't modify this one. Rare enough that the gc
-      // overhead is almost certainly lower than the alternate, which
-      // would be clone to support rollback.
-
-      bufferedDeleteTerms = new HashMap();
-      numBufferedDeleteTerms = 0;
     }
+
+    return delCount;
   }
 
   private final boolean checkNonDecreasingLevels(int start) {
@@ -2410,59 +2366,28 @@ public class IndexWriter {
 
   // For test purposes.
   final synchronized int getBufferedDeleteTermsSize() {
-    return bufferedDeleteTerms.size();
+    return docWriter.getBufferedDeleteTerms().size();
   }
 
   // For test purposes.
   final synchronized int getNumBufferedDeleteTerms() {
-    return numBufferedDeleteTerms;
+    return docWriter.getNumBufferedDeleteTerms();
-  }
-
-  // Number of ram segments a delete term applies to.
-  private static class Num {
-    private int num;
-
-    Num(int num) {
-      this.num = num;
-    }
-
-    int getNum() {
-      return num;
-    }
-
-    void setNum(int num) {
-      this.num = num;
-    }
-  }
-
-  // Buffer a term in bufferedDeleteTerms, which records the
-  // current number of documents buffered in ram so that the
-  // delete term will be applied to those ram segments as
-  // well as the disk segments.
-  private void bufferDeleteTerm(Term term) {
-    Num num = (Num) bufferedDeleteTerms.get(term);
-    int numDoc = docWriter.getNumDocsInRAM();
-    if (num == null) {
-      bufferedDeleteTerms.put(term, new Num(numDoc));
-    } else {
-      num.setNum(numDoc);
-    }
-    numBufferedDeleteTerms++;
   }
 
   // Apply buffered delete terms to the segment just flushed from ram
   // apply appropriately so that a delete term is only applied to
   // the documents buffered before it, not those buffered after it.
-  private final void applyDeletesSelectively(HashMap deleteTerms,
+  private final int applyDeletesSelectively(HashMap deleteTerms,
       IndexReader reader) throws CorruptIndexException, IOException {
     Iterator iter = deleteTerms.entrySet().iterator();
+    int delCount = 0;
     while (iter.hasNext()) {
       Entry entry = (Entry) iter.next();
       Term term = (Term) entry.getKey();
 
       TermDocs docs = reader.termDocs(term);
       if (docs != null) {
-        int num = ((Num) entry.getValue()).getNum();
+        int num = ((DocumentsWriter.Num) entry.getValue()).getNum();
         try {
           while (docs.next()) {
             int doc = docs.doc();
@@ -2470,21 +2395,37 @@ public class IndexWriter {
               break;
             }
             reader.deleteDocument(doc);
+            delCount++;
           }
         } finally {
           docs.close();
         }
       }
     }
+    return delCount;
   }
 
   // Apply buffered delete terms to this reader.
-  private final void applyDeletes(HashMap deleteTerms, IndexReader reader)
+  private final int applyDeletes(HashMap deleteTerms, IndexReader reader)
       throws CorruptIndexException, IOException {
     Iterator iter = deleteTerms.entrySet().iterator();
+    int delCount = 0;
     while (iter.hasNext()) {
       Entry entry = (Entry) iter.next();
-      reader.deleteDocuments((Term) entry.getKey());
+      delCount += reader.deleteDocuments((Term) entry.getKey());
     }
+    return delCount;
+  }
+
+  public synchronized String segString() {
+    StringBuffer buffer = new StringBuffer();
+    for(int i = 0; i < segmentInfos.size(); i++) {
+      if (i > 0) {
+        buffer.append(' ');
+      }
+      buffer.append(segmentInfos.info(i).name + ":" + segmentInfos.info(i).docCount);
+    }
+
+    return buffer.toString();
   }
 }

src/test/org/apache/lucene/index/TestAtomicUpdate.java

@@ -0,0 +1,184 @@
+package org.apache.lucene.index;
+
+/**
+ * Copyright 2004 The Apache Software Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import org.apache.lucene.util.*;
+import org.apache.lucene.store.*;
+import org.apache.lucene.document.*;
+import org.apache.lucene.analysis.*;
+import org.apache.lucene.index.*;
+import org.apache.lucene.search.*;
+import org.apache.lucene.queryParser.*;
+import org.apache.lucene.util._TestUtil;
+
+import junit.framework.TestCase;
+
+import java.util.Random;
+import java.io.File;
+
+public class TestAtomicUpdate extends TestCase {
+  private static final Analyzer ANALYZER = new SimpleAnalyzer();
+  private static final Random RANDOM = new Random();
+
+  private static abstract class TimedThread extends Thread {
+    boolean failed;
+    int count;
+    private static int RUN_TIME_SEC = 3;
+    private TimedThread[] allThreads;
+
+    abstract public void doWork() throws Throwable;
+
+    TimedThread(TimedThread[] threads) {
+      this.allThreads = threads;
+    }
+
+    public void run() {
+      final long stopTime = System.currentTimeMillis() + 1000*RUN_TIME_SEC;
+
+      count = 0;
+
+      try {
+        while(System.currentTimeMillis() < stopTime && !anyErrors()) {
+          doWork();
+          count++;
+        }
+      } catch (Throwable e) {
+        e.printStackTrace(System.out);
+        failed = true;
+      }
+    }
+
+    private boolean anyErrors() {
+      for(int i=0;i<allThreads.length;i++)
+        if (allThreads[i] != null && allThreads[i].failed)
+          return true;
+      return false;
+    }
+  }
+
+  private static class IndexerThread extends TimedThread {
+    IndexWriter writer;
+    public int count;
+
+    public IndexerThread(IndexWriter writer, TimedThread[] threads) {
+      super(threads);
+      this.writer = writer;
+    }
+
+    public void doWork() throws Exception {
+      // Update all 100 docs...
+      for(int i=0; i<100; i++) {
+        Document d = new Document();
+        int n = RANDOM.nextInt();
+        d.add(new Field("id", Integer.toString(i), Field.Store.YES, Field.Index.UN_TOKENIZED));
+        d.add(new Field("contents", English.intToEnglish(i+10*count), Field.Store.NO, Field.Index.TOKENIZED));
+        writer.updateDocument(new Term("id", Integer.toString(i)), d);
+      }
+    }
+  }
+
+  private static class SearcherThread extends TimedThread {
+    private Directory directory;
+
+    public SearcherThread(Directory directory, TimedThread[] threads) {
+      super(threads);
+      this.directory = directory;
+    }
+
+    public void doWork() throws Throwable {
+      IndexReader r = IndexReader.open(directory);
+      try {
+        assertEquals(100, r.numDocs());
+      } catch (Throwable t) {
+        throw t;
+      }
+      r.close();
+    }
+  }
+
+  /*
+    Run one indexer and 2 searchers against single index as
+    stress test.
+  */
+  public void runTest(Directory directory) throws Exception {
+
+    TimedThread[] threads = new TimedThread[4];
+
+    IndexWriter writer = new IndexWriter(directory, ANALYZER, true);
+
+    // Establish a base index of 100 docs:
+    for(int i=0;i<100;i++) {
+      Document d = new Document();
+      d.add(new Field("id", Integer.toString(i), Field.Store.YES, Field.Index.UN_TOKENIZED));
+      d.add(new Field("contents", English.intToEnglish(i), Field.Store.NO, Field.Index.TOKENIZED));
+      writer.addDocument(d);
+    }
+
+    IndexerThread indexerThread = new IndexerThread(writer, threads);
+    threads[0] = indexerThread;
+    indexerThread.start();
+    
+    IndexerThread indexerThread2 = new IndexerThread(writer, threads);
+    threads[1] = indexerThread2;
+    indexerThread2.start();
+      
+    SearcherThread searcherThread1 = new SearcherThread(directory, threads);
+    threads[2] = searcherThread1;
+    searcherThread1.start();
+
+    SearcherThread searcherThread2 = new SearcherThread(directory, threads);
+    threads[3] = searcherThread2;
+    searcherThread2.start();
+
+    indexerThread.join();
+    indexerThread2.join();
+    searcherThread1.join();
+    searcherThread2.join();
+
+    writer.close();
+
+    assertTrue("hit unexpected exception in indexer", !indexerThread.failed);
+    assertTrue("hit unexpected exception in indexer2", !indexerThread2.failed);
+    assertTrue("hit unexpected exception in search1", !searcherThread1.failed);
+    assertTrue("hit unexpected exception in search2", !searcherThread2.failed);
+    //System.out.println("    Writer: " + indexerThread.count + " iterations");
+    //System.out.println("Searcher 1: " + searcherThread1.count + " searchers created");
+    //System.out.println("Searcher 2: " + searcherThread2.count + " searchers created");
+  }
+
+  /*
+    Run above stress test against RAMDirectory and then
+    FSDirectory.
+  */
+  public void testAtomicUpdates() throws Exception {
+
+    Directory directory;
+
+    // First in a RAM directory:
+    directory = new MockRAMDirectory();
+    runTest(directory);
+    directory.close();
+
+    // Second in an FSDirectory:
+    String tempDir = System.getProperty("java.io.tmpdir");
+    File dirPath = new File(tempDir, "lucene.test.atomic");
+    directory = FSDirectory.getDirectory(dirPath);
+    runTest(directory);
+    directory.close();
+    _TestUtil.rmDir(dirPath);
+  }
+}

src/test/org/apache/lucene/index/TestIndexWriterDelete.java

@@ -436,6 +436,7 @@ public class TestIndexWriterDelete extends TestCase {
           catch (IOException e) {
             if (debug) {
               System.out.println("  hit IOException: " + e);
+              e.printStackTrace(System.out);
             }
             err = e;
             if (1 == x) {
@@ -503,10 +504,20 @@ public class TestIndexWriterDelete extends TestCase {
           }
           int result2 = hits.length();
           if (success) {
-            if (result2 != END_COUNT) {
+            if (x == 0 && result2 != END_COUNT) {
               fail(testName
                    + ": method did not throw exception but hits.length for search on term 'aaa' is "
                    + result2 + " instead of expected " + END_COUNT);
+            } else if (x == 1 && result2 != START_COUNT && result2 != END_COUNT) {
+              // It's possible that the first exception was
+              // "recoverable" wrt pending deletes, in which
+              // case the pending deletes are retained and
+              // then re-flushing (with plenty of disk
+              // space) will succeed in flushing the
+              // deletes:
+              fail(testName
+                   + ": method did not throw exception but hits.length for search on term 'aaa' is "
+                   + result2 + " instead of expected " + START_COUNT + " or " + END_COUNT);
             }
           } else {
             // On hitting exception we still may have added
@@ -515,7 +526,7 @@ public class TestIndexWriterDelete extends TestCase {
               err.printStackTrace();
               fail(testName
                    + ": method did throw exception but hits.length for search on term 'aaa' is "
-                   + result2 + " instead of expected " + START_COUNT);
+                   + result2 + " instead of expected " + START_COUNT + " or " + END_COUNT);
             }
           }
 
@@ -535,10 +546,8 @@ public class TestIndexWriterDelete extends TestCase {
     }
   }
 
-  // This test tests that buffered deletes are not lost due to i/o
+  // This test tests that buffered deletes are cleared when
-  // errors occurring after the buffered deletes have been flushed but
+  // an Exception is hit during flush.
-  // before the segmentInfos have been successfully written
-
   public void testErrorAfterApplyDeletes() throws IOException {
     
     MockRAMDirectory.Failure failure = new MockRAMDirectory.Failure() {
@@ -662,9 +671,11 @@ public class TestIndexWriterDelete extends TestCase {
 
       hitCount = getHitCount(dir, term);
 
-      // If we haven't lost the delete the hit count will be zero
+      // If the delete was not cleared then hit count will
-
+      // be 0.  With autoCommit=false, we hit the exception
-      assertEquals(0, hitCount);
+      // on creating the compound file, so the delete was
+      // flushed successfully.
+      assertEquals(autoCommit ? 1:0, hitCount);
 
       if (autoCommit) {
         modifier.close();