Are there any recommendations for integrating Lucene.NET into an ASP.NET MVC application?

Question

I'm wondering if there are any recommendations, best practises or top-tips for integrating a Lucene.NET based search into an ASP.NET MVC web application?

Things I've read (or think I've read) in various places include the following:

• One IndexWriter , many IndexReader s
• When the index is updated, reset/ re-initialise the IndexReader s

Are there any other useful tips or resources I should read before starting?

Thanks,
Kieron

Answer 1

Here are my tips (in no particular order):

• Choose the most appropriate locking mechanism.
• Use the SetRAMBufferSizeMB to reduce the disk I/O overhead when writing the index.
• Don't over use the SetMaxBufferedDocs property.
• Use the Search hits (TopDocs and ScoreDoc[]) object to retrieve the index search results.
• Index writing is an expensive operation, so use it sparingly.
• Know the data that you will be indexing as some data types (IE, dates) can be difficult to search on if they are not stored consistently.

A few gotchas from one of my previous projects were:

• I had to use the BooleanQuery to do a traditional AND operation for searching multiple fields.
• There is no UPDATE functionality within Lucene so a document needs to be deleted and re-added.
• You can't sort / OrderBy on a tokenized field.

I would suggest looking at the source code for RavenDb as it is built on top of Lucene and uses a number of best practices.

Answer 2

RavenDb is definitely the easiest way to go here -- it really is lucene++.

In terms of how to use it, I'd recommend looking at the SubText blogging engine. Code is MIT licensed so you can just use it in your project and it has a very well designed index writer/reader.

In our apps, we tend to have one writer and a separate app with many readers. The locking strategy can be key here--especially make sure the readers don't try and lock the index. I'm blanking on the specific term we had to use to make this happen.