Elasticsearch NEST重用ElasticClient进行不同的索引查询

Question

如何在.NET Core应用程序中将ElasticClient注册为单例，但仍能在查询期间指定不同的索引？

例如：

在Startup.cs中，我将弹性客户端对象注册为单例，只提及URL而不指定索引。

public void ConfigureServices(IServiceCollection services)
{
    ....
    var connectionSettings = new ConnectionSettings(new Uri("http://localhost:9200"));
    var client = new ElasticClient(connectionSettings);
    services.AddSingleton<IElasticClient>(client);
    ....
}

然后在上面注入ElasticClient单例对象时，我想将它用于2个不同查询中的不同索引。

在下面的类中，我想从一个名为“Apple”的索引查询

public class GetAppleHandler
{   
    private readonly IElasticClient _elasticClient;

    public GetAppleHandler(IElasticClient elasticClient)
    {
        _elasticClient = elasticClient;
    }

    public async Task<GetAppleResponse> Handle()
    {
        // I want to query (_elasticClient.SearchAsync<>) using an index called "Apple" here
    }
}

从下面的代码我想从一个名为“橙色”的索引查询

public class GetOrangeHandler
{   
    private readonly IElasticClient _elasticClient;

    public GetOrangeHandler(IElasticClient elasticClient)
    {
        _elasticClient = elasticClient;
    }

    public async Task<GetOrangeResponse> Handle()
    {
        // I want to query (_elasticClient.SearchAsync<>) using an index called "Orange" here
    }
}

我怎样才能做到这一点？如果不可能，您能否建议其他方法允许我通过.NET Core依赖注入注入ElasticClient，同时还允许我从同一ES实例的2个不同索引进行查询？

Answer 1

只需要在请求中指定索引

var defaultIndex = "person";
var pool = new SingleNodeConnectionPool(new Uri("http://localhost:9200"));

var settings = new ConnectionSettings(pool)
    .DefaultIndex(defaultIndex)
    .DefaultTypeName("_doc");

var client = new ElasticClient(settings);

var searchResponse = client.Search<Person>(s => s
    .Index("foo_bar")
    .Query(q => q
        .Match(m => m
            .Field("some_field")
            .Query("match query")
        )
    )
);

搜索请求将在此处

POST http://localhost:9200/foo_bar/_doc/_search
{
  "query": {
    "match": {
      "some_field": {
        "query": "match query"
      }
    }
  }
}

• foo_bar索引已在搜索请求中定义
• _doc类型已经从DefaultTypeName("_doc")的全球规则中推断出来