[LUCENE-1399] NullPointerException issue with single IndexWriter instance shared among multiple Thread

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.3.2
• Fix Version/s: 2.4
• Component/s: core/index

Environment

Windows XP, JDK 1.6

• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Rudi Quark
• Created: 22/Sep/08 07:03
• Updated: 28/Aug/22 11:53
• Resolved: 23/Sep/08 08:34

Description

NullPointerException is thrown while indexing within multiple threads but using one single IndexWriter instance. According to "Lucene in Action" this should do: "...a single instance of either class can be shared among multiple threads, and all calls to its index-modifying methods will be properly synchronized so that index modifications are executed one after the other."

Following my exception trace:

java.lang.NullPointerException
at org.apache.lucene.index.IndexFileDeleter.decRef(IndexFileDeleter.java:475)
at org.apache.lucene.index.IndexWriter.commitTransaction(IndexWriter.java:1986)
at org.apache.lucene.index.IndexWriter.addIndexes(IndexWriter.java:2219)
at com.shi.marketingspy.test.SHILuceneWritingFromThreadsTest$testthread.run(SHILuceneWritingFromThreadsTest.java:48)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
at java.lang.Thread.run(Thread.java:619)

Following my test program:

package com.shi.marketingspy.test;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.index.IndexWriter;

public class SHILuceneWritingFromThreadsTest
{
public static void log(String s, com.shi.jipmisc misc)

{ misc.__Log(s); }

public static class testthread implements Runnable
{
public org.apache.lucene.index.IndexWriter indexwriter;
public int iThread;
public boolean bWithOptimize;
public com.shi.jipmisc misc;

public testthread(org.apache.lucene.index.IndexWriter indexwriter, int iThread, boolean bWithOptimize, com.shi.jipmisc misc)

{ this.indexwriter = indexwriter; this.iThread = iThread; this.bWithOptimize = bWithOptimize; this.misc = misc; }

public void run()
{
try
{
Analyzer anal = new com.shi.lucene.index.SHIAnalyser(null,null);
org.apache.lucene.store.Directory tmpidxdirectory = new org.apache.lucene.store.RAMDirectory();
org.apache.lucene.index.IndexWriter tempindexwriter = new IndexWriter(tmpidxdirectory, anal, true);

Document doc = new Document();
for(int ifld=0; ifld < 9; ifld++)

{ doc.add(new Field("field_"+ifld, "iThread: "+iThread+" field: "+ifld+" "+System.currentTimeMillis()+" "+misc.getDateString()+" "+misc.getDateString2()+" "+com.shi.jipmisc.getTimeStamp()+" "+misc.getClass()+" "+misc.getDebug(), Store.COMPRESS, Field.Index.UN_TOKENIZED)); }

tempindexwriter.addDocument(doc);
tempindexwriter.optimize();
org.apache.lucene.store.Directory[] idxs = new org.apache.lucene.store.Directory[1];
idxs[0] = tmpidxdirectory;
//todo: del-call...
this.indexwriter.addIndexes(idxs);
if (this.bWithOptimize)
this.indexwriter.optimize();
}
catch(Throwable e)

{ log("testthread:run\tERR:2(bWithOpti:"+bWithOptimize+")(iThread:"+iThread+"):"+e.getMessage()+"\n\t"+com.shi.jipmisc.stack2string(e), misc); }

}
}

public SHILuceneWritingFromThreadsTest()
{

}

public static void main(String[] args)

{ testluceneconcurrency(false); testluceneconcurrency(true ); }

public static java.util.concurrent.ExecutorService threadpool_optimized = java.util.concurrent.Executors.newFixedThreadPool(9999999);
public static java.util.concurrent.ExecutorService threadpool_not_optimized = java.util.concurrent.Executors.newFixedThreadPool(9999999);

public static void testluceneconcurrency(boolean bWithOptimize)
{
com.shi.jipmisc.createDir("temp", "c:");
com.shi.jipmisc.createDir("testluceneconcurrency", "c:/temp");
com.shi.jipmisc.createDir(""+bWithOptimize, "c:/temp/testluceneconcurrency");
com.shi.jipmisc misc = new com.shi.jipmisc();
misc.setMyPath("C:/temp/testluceneconcurrency");
misc.setDebug(true);
misc.emptyDir("c:/temp/testluceneconcurrency/"+bWithOptimize);
Analyzer anal = new com.shi.lucene.index.SHIAnalyser(null,null);
org.apache.lucene.index.IndexWriter indexwriter = null;
try

{ indexwriter = new IndexWriter("c:/temp/testluceneconcurrency/"+bWithOptimize, anal, true); }

catch(Throwable e)

{ log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tERR:0("+bWithOptimize+"):"+e.getMessage(), misc); return; }

log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tINF:step0("bWithOptimize")(BEGIN)-------------------------------------", misc);

for(int idoc=0; idoc < 9999; idoc++)
{
Document doc = new Document();
for(int ifld=0; ifld < 9; ifld++)

{ doc.add(new Field("field_"+ifld, "doc: "+idoc+" field: "+ifld+" "+System.currentTimeMillis()+" "+misc.getDateString()+" "+misc.getDateString2()+" "+com.shi.jipmisc.getTimeStamp()+" "+misc.getClass()+" "+misc.getDebug(), Store.COMPRESS, Field.Index.UN_TOKENIZED)); }

try

{ indexwriter.addDocument(doc); }

catch(Throwable e)

{ log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tERR:1("+bWithOptimize+"):"+e.getMessage(), misc); return; }

}
log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tINF:step1("bWithOptimize")", misc);
try

{ indexwriter.optimize(); }

catch(Throwable e)

{ log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tERR:2("+bWithOptimize+"):"+e.getMessage(), misc); return; }

log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tINF:step2("bWithOptimize")", misc);
java.util.concurrent.ExecutorService threadpool = bWithOptimize ? threadpool_optimized : threadpool_not_optimized;
for(int it=0; it < 999; it++)

{ threadpool.execute(new testthread(indexwriter, it, bWithOptimize, misc)); }

log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tINF:step3("bWithOptimize")", misc);
threadpool.shutdown(); //=execute threads and wait til all threads finish
com.shi.jipmisc.wait(999, misc);
log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tINF:step4("bWithOptimize")", misc);

try

{ //indexwriter.optimize(); //indexwriter.close(); }

catch(Throwable e)

{ log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tERR:9("+bWithOptimize+"):"+e.getMessage(), misc); return; }

log("SHILuceneWritingFromThreadsTest:testluceneconcurrency\tINF:step5("bWithOptimize")(END)-----------------------------", misc);
}
}