Slow Lucene.Net search performance

Question

Facing slow search performance using Lucene.Net (+ NHibernate.Search but that doesn't matter).

Luke toolbox overview:

• Number of fields: 33
• Number of documents: 5607
• Number of terms: 101377
• Has deletions? / Optimized?: Yes (97478) / No

Index directory is ~200Mb large.

Query (using org.apache.lucene.analysis.SimpleAnalyzer)

Title:lapsa~0.5 Abstract:lapsa~0.5 Content:lapsa~0.5 Location:lapsa~0.5 Author:lapsa~0.5

takes ~60000ms in average.

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I suspect I'm missing something important. Any ideas what's wrong? Can't be that this is normal.

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Tried to 'check' and 'fix' them. Had to tick Don't open IndexReader (when opening corrupted index), otherwise Check index tool doesn't want to show up.

Results of checking:

BAD: missingSegments

Diagnostic output:

ERROR: could not read any segments file in directory java.io.FileNotFoundException: no segments* file found in org.apache.lucene.store.FSDirectory@D:\Temp\Index: files: at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:655) at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:538) at org.apache.lucene.index.SegmentInfos.read(SegmentInfos.java:306) at org.apache.lucene.index.CheckIndex.checkIndex(CheckIndex.java:340) at org.apache.lucene.index.CheckIndex.checkIndex(CheckIndex.java:319) at org.getopt.luke.Luke$6.run(Unknown Source)

Tried to press Fix Index. Got this:

ERROR during Fix Index: java.lang.NullPointerException at org.apache.lucene.index.CheckIndex.fixIndex(CheckIndex.java:781) at org.getopt.luke.Luke$7.run(Unknown Source)

Answer 1

In Luke go to the Tools menu and select check index tool. See if your index is corrupted or has other issues.

Answer 2

Sounds to me like you've got a corrupted index. Are there any files in your D:\Temp\Index folder? I assume there must be or searching wouldn't work at all... What version of Lucene.Net are you using? Earlier versions used to corrupt the index for me at the drop of a hat, but the later versions seem to be much better in that respect.

If you can't figure it out, you might just have to rebuild the index from scratch.

Answer 3

This one helped me. Switched on automatic optimization.