Singleton search context for search api

Question

Typical usage of search api uses a using statement to dispose of the search context.

 using (var context = ContentSearchManager.GetIndex(_indexName).CreateSearchContext())
 {
     var hits = context.GetQueryable<SearchResult>();
     return hits;
 }

This runs into a problem with hits.result or lucene reader being disposed before it can be used by the calling method. This may be more likely if creating a search service rather than calling this (for example) within an MVC controller.

Often this disposal problem is addressed by calling ToList() creating an IEnumerable<SearchResult> and returning that instead.

return hits.ToList()

By doing this, we loose hits.GetResults() and the properties within - Hits, TotalSearchResults and Facets

An alternative approach mentioned is to use a single search context that is not disposed and instead reused across the application.

Question

• Is using a single, reused context a good approach?
• Are there any pitfalls?
• Are there any good code examples of doing this, possibly with a dependency injection framework handling a singleton.

Answer 1

Is using a single, reused context a good approach?

Yes. It is the recommended approach.

Are there any pitfalls?

Yes. New documents added to your indexes will not show, until you re-open a new Search Context. So you may need to tie in your SearchContext to index update events.

Are there any good code examples of doing this, possibly with a dependency injection framework handling a singleton.

Because of the pitfalls, setting this up in a DI Singleton is probably not a good idea. For an on-source reference and explanation, see Sitecore 7 Patterns for Global Search Context Reuse