I did some searches for this issue and didn't find anything. Apologies
if this is known.
I am calling IndexWriter.GetReader() from an IndexWriter instance which
is getting used in a multithreaded scenario. I want to do real-time
searches against potentially uncommitted documents. My indexing
infrastructure keeps only one IndexWriter open at a time (of course).
Works great except that very rarely the request to GetReader() will
throw a NullReferenceException. Here is the stack trace:
System.NullReferenceException: Object reference not set to an instance
of an object.
at Lucene.Net.Index.SegmentReader.Norm.Clone()
at Lucene.Net.Index.SegmentReader.ReopenSegment(SegmentInfo si,
Boolean doClone, Boolean openReadOnly)
at Lucene.Net.Index.SegmentReader.Clone(Boolean openReadOnly)
at
Lucene.Net.Index.IndexWriter.ReaderPool.GetReadOnlyClone(SegmentInfo
info, Boolean doOpenStores, Int32 termInfosIndexDivisor)
at Lucene.Net.Index.DirectoryReader..ctor(IndexWriter writer,
SegmentInfos infos, Int32 termInfosIndexDivisor)
at Lucene.Net.Index.IndexWriter.GetReader(Int32
termInfosIndexDivisor)
at Lucene.Net.Index.IndexWriter.GetReader()
at Dovetail.Search.Indexing.IndexWriterWrapper.withSearcher[T](Func`2
func)
at
Dovetail.Search.Indexing.LuceneDocumentFinder.GetDocumentByUrl(String
uri)
at ...
For context. My withSearcher<T> code:
public T withSearcher<T>(Func<IndexSearcher, T> func)
{
var indexReader = _indexWriter.GetReader();
var searcher = new IndexSearcher(indexReader);
try
{
return func(searcher);
}
finally
{
searcher.Close();
indexReader.Close();
}
}
If it helps I am using a FSDirectory. Any suggestions? Or ideas how I
might better characterize this?
I can work around by switching back to searching on committed documents
via a search created from a read-only IndexReader from a Directory. I
wanted to do real time searches to avoid explicit commits (which are not
always necessary) in my indexing workflow.
Kevin @ Dovetail Software
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