Proper LINQ to Lucene Index<T> usage pattern for ASP.NET?

What is the proper usage pattern for LINQ to Lucene's Index<T>?

It implements IDisposible so I figured wrapping it in a using statement would make the most sense:

IEnumerable<MyDocument> documents = null;

using (Index<MyDocument> index = new Index<MyDocument>(new System.IO.DirectoryInfo(IndexRootPath)))
{
    documents = index.Where(d => d.Name.Like("term")).ToList();
}

I am occasionally experiencing unwanted deleting of the index on disk. It seems happen 100% of the time if multiple instances of the Index exist at t开发者_高级运维he same time. I wrote a test using PLINQ to run 2 searches in parallel and 1 search works while the other returns 0 results because the index is emptied.

• Am I supposed to use a single static instance instead?
• Should I wrap it in a Lazy<T>?
• Am I then opening myself up to other issues when multiple users access the static index at the same time?

I also want to re-index periodically as needed, likely using another process like a Windows service. Am I also going to run into issues if users are searching while the index is being rebuilt?

The code looks like Linq-to-Lucene.

Most cases of completely cleared Lucene indexes are new IndexWriters created with the create parameter set to true. The code in the question does not handle indexing so debugging this further is difficult.

Lucene.Net is thread-safe, and I expect linq-to-lucene to also inhibit this behavior. A single static index instance would cache stuff in memory, but I guess you'll need to handle index reloading of changes yourself (I do not know if linq-to-lucene does this for you).

There should be no problems using several searchers/readers when reindexing, Lucene is build to support that scenario. However, there can only be one writer per directory, so no other process can write documents to the index while your windows service were to optimize the index.