Search Providers

Orleans.Search uses a pluggable provider architecture that allows you to use different database backends for your search index.

How Providers Work

A search provider is responsible for:

1. Storing grain state in a searchable database
2. Translating LINQ queries to database-specific queries
3. Returning grain IDs that match search predicates
4. Full-text search (optional, database-specific)

Architecture

IClusterClient.Search<TGrain>()
    |
    v
OrleansQueryProvider (LINQ translation)
    |
    v
ISearchProvider<TGrain, TState>
    |
    v
SearchProviderBase<TGrain, TState, TEntity>
    |
    v
Database-Specific Provider (PostgreSQL, etc.)
    |
    v
Database (PostgreSQL, SQL Server, etc.)

Available Providers

Choosing a Provider

PostgreSQL

Best for:

• Production workloads
• Full-text search with ranking
• Complex queries with multiple filters
• Large datasets requiring indexes

builder.Services.AddOrleansSearch()
    .UsePostgreSql(connectionString);

Custom Providers

You can create custom providers for other databases. See Creating Custom Providers for details.

Provider Registration

All providers follow the same registration pattern:

var builder = WebApplication.CreateBuilder(args);
 
// Configure Orleans
builder.UseOrleans(siloBuilder =>
{
    siloBuilder.UseLocalhostClustering();
    siloBuilder.AddMemoryGrainStorage("InnerStorage");
    siloBuilder.AddSearchableGrainStorage("InnerStorage");
});
 
// Add Orleans.Search with your chosen provider
builder.Services.AddOrleansSearch()
    .UsePostgreSql(connectionString);  // Or your custom provider

Source-Generated Components

When you mark a grain state with [Searchable], the source generator creates:

These generated components work with any provider that uses Entity Framework Core.

Next Steps

• PostgreSQL Provider - Configure PostgreSQL
• Creating Custom Providers - Build your own provider